# Compression check on a 383 stroker...! Uploaded Video of new motor.



## Georgiadawgs78 (Jun 21, 2009)

Ok a while back i cracked a cylinder in my jeep thats in my avator. So I pulled the motor and took it to a local machine shop where i spent a little over 3K to do a total makeover and throw in an all forged 383 stroker kit with all forged pistons, h beam rods, and 400 crank. I also put new rods and lifters but left the old cam. I vatted the block, replaced cam bearings and freeze plugs, and everything else. I didnt touch the heads, intake, carb, or cam. The motor now has 140 miles on it since I put it in. Here lately it started running like complete crap. It will rev up like a sure beauty but when you put it in gear and take off it is slow and feels like it is just bogging down. This thing use to be FAST! So anyways I decided to check the compression and it was all out of wack. 

1-210
3-170
5-90
7-210
2-235
4-225
6-10
8-120 This one was real jumpy sometimes 30 and sometimes 90....It would just hit on the first turnover and thats it.

So what would you say would be wrong with it. I have heard many different things! One being the rings arent spaced right so its loosing compression, two the valves arent right and that the heads need a valve job, and three that the cam or lifters are shot since I put new lifters in with the old cam that was already wore down to match the old lifters so the cam isnt opening and closing the valves like it is suppose to. 

I talked to the maching shop that worked on it and he threw it off on the heads...probably because he has nothing to do with heads since he didnt touch them. Everybody else says its in the rings or a hole in the piston. I also noticed today that when I first cranked it that the left side exhause smoked like crazy for about 30 seconds. The machine shop man said for me to pull the motor and that he would look at it but who knows the cost. But if he really thinks that it is in the heads then why not just pull the heads since it would be ten times easier than the whole motor. Any help would be greatly appreciated.

Thanks,

Big D


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## stevetarget (Jun 21, 2009)

I would check the heads first


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## jrry (Jun 21, 2009)

Check for cam timing - time chain could be out of time


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## Jranger (Jun 21, 2009)

How did your plugs look on the left side when you checked compression? Smoke usually means oil is seeping back in past the rings if I'm not mistaken.


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## redneckcamo (Jun 21, 2009)

bent valves would be my first guess ...

did ya check the clearance with the new pistons ?  flat tops or domes ?

what kinda compression do ya have ...10 to 1...  9 to 1 ...8 to 1 ?

on the cam ...roller lifters or flat tappet ?

give us a little more info on the engine !!

and if you put new lifters on an old cam that is a flat tappet cam ....you may have wore the lobes down real fast ......THAT IS A HUGE NO NO in engine building !!!


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## Davans (Jun 21, 2009)

Jumped timimg, bent valves / Push tubes ?


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## Slug-Gunner (Jun 21, 2009)

*$3K+ for HALF-A-JOB*



Georgiadawgs78 said:


> Ok a while back i cracked a cylinder in my jeep thats in my avator. So I pulled the motor and took it to a local machine shop where i spent a little over 3K to do a total makeover and throw in an all forged 383 stroker kit with all forged pistons, h beam rods, and 400 crank. I also put new rods and lifters but left the old cam. I vatted the block, replaced cam bearings and freeze plugs, and everything else. I didnt touch the heads, intake, carb, or cam. The motor now has 140 miles on it since I put it in. Here lately it started running like complete crap. It will rev up like a sure beauty but when you put it in gear and take off it is slow and feels like it is just bogging down. This thing use to be FAST! So anyways I decided to check the compression and it was all out of wack.
> 
> 1-210
> 3-170
> ...




Big D,
First question - who did all the assembly work? What is year model of the engine?
How many miles were on the engine when it was HALF-WAY rebuilt? Did you put a NEW oil pump in it? Who's idea was it NOT TO REPLACE THE CAM or HAVE THE HEADS REBUILT TOO? Were NEW timing chain and gears installed? 
Were you there when the 'initial run-up' of the newly rebuilt engine was done? 

You say the engine only has 140 miles on it and is ALREADY 'SHOT'! My first guess is that "You just couldn't wait to see what kind of power that 383 'Stroker' had and 'what it could do' and TESTED IT BEFORE LETTING THE RINGS GET _PROPERLY SEATED_."  If so, you probably 'glazed' the cylinder walls or 'cracked a ring'.

Most likely what you have is CAMSHAFT and LIFTER FAILURE. This can be easily checked by pulling the valve covers and using a dial indicator gauge on the rocker arm ends to determine the 'amount of lift' on each rocker arm as the engine is turned over by hand. 

There is also the possibility of "head gasket failure" between cylinders 3 & 4 and 6 & 8 (adjoining cylinders) since YOU DIDN'T HAVE THE HEADS 'RESURFACED' for trueness. 

Since you effectively increased the cu. in. displacement with the stroker kit, and didn't modify the carburetor, you may have been running TOO LEAN and burned some valves too.

I would normally suggest a CYLINDER LEAK-DOWN TEST, but that is probably 'pointless' at this time considering your compression readings. This would help determine if the 'loss of compression' was due to valve or piston ring problems by 'listening' for where the 'air leakage' is coming from - carburetor inlet or oil filler cap areas.


Considering the 'smoking for 30 seconds' on initial startup, that is sometimes 'normal' considering that excessive oil or 'assembly lube' may be present on cylinder walls and rings to insure adequate lubrication until oil pressure and flow is present.

Whether to just 'pull the engine' or 'only pull the heads' is a toss-up since you're most likely going to have to change the camshaft (and maybe bearings too) and lifters. Which is easier.... pulling the engine; or pulling the front of the jeep off to change the camshaft? 

While the heads are off, they can do a 'vacuum test' on each cylinder to determine the condition of the rings and HOW WELL THEY'RE SEATING. At least that's what I would do BEFORE TEARING ANYTHING COMPLETELY APART since YOU DON'T RE-USE OLD RINGS ONCE THEY ARE REMOVED FROM THE CYLINDERS.

Sorry if I sound 'sarcastic' and 'harsh', but I've seen this similar situation happen ALL TOO OFTEN over my 50+ years of automotive work. People trying to 'save a few bucks' and doing a job HALF-WAY.... only to have it FAIL and cost them TWICE AS MUCH in the end. 

I've had people wanting to rebuild their engine and then NOT WANT TO PUT A NEW OIL PUMP OR WATER PUMP IN IT.  If so, sorry - my guarantee is 'only out the door'. (When I put it to them that way, they usually would agree with me to add those items.)

Personally, I wouldn't have agreed to NOT PUT A NEW CAMSHAFT IN without giving you a REAL HARD TIME and ABSOLUTELY NO GUARANTEE if you didn't. I've seen them FAIL TOO MANY TIMES because owners didn't put 'new lifters' in with a new camshaft or vise-versa. Even then, if a new camshaft and lifters ARE NOT 'RUN-IN' PROPERLY FOR 20 MINUTES = THEY CAN FAIL PREMATURELY. (One of the BIGGEST CAUSES of camshaft lobe/lifter failure.)

"Penny-wise and pound foolish." comes to mind.

_Well, you've LEARNED ONE THING.... "DO IT RIGHT THE FIRST TIME!"_


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## deadend (Jun 21, 2009)

The ring spacing issue is nonexistant because rings rotate in normal engine operation.  I would look first at the cam issues.  I cannot think of a bigger NO-NO than what you did with the cam.  

Another issue could be the run in.  If you did not properly break in the engine and severely overloaded it in the first hour of its life wanting to try it out you probably trashed the rings and maybe some other stuff.

Not to sound harsh but you would have been better off buying a crate engine instead of trying to build an engine without the proper know how and parts.


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## Georgiadawgs78 (Jun 21, 2009)

Well I took to hops speed shop and let him do all the work he asked me what the oil pressure was running and i told him what it was when it was idling and he said that it had plenty of pressure. I took him every piece of the motor and told him what was up and he took it from there. He never said that I needed a new cam or I would have spent the money in the first place. I trusted him that he knew what he was doing and would fix it up right. I didnt give the motor straight heck. I hardly ever give it heck and especially didnt give it heck when I first got it back in the jeep. I didnt have the carburetor butterfly held open all the way so I will try that and see what the readings are. Maybe that was the problem a little but either way it still isnt right. The heads were trued up and the block was decked. The motor is in the 70's model and I have no clue how many miles were on it due to the speedometer wasnt hooked up. But i had put around 850 miles on it. It has scorpion 1.6 roller rockers with a crowler cam. Vic jr edelbock aluminum intake with holley aed carb (Think its a 750 but not sure) It has a double timing chain and as far as I know he didnt replace it or the gears. I was present for the final assembly and start up. Again i wasnt trying to save money if i was i wouldnt have put an all forged stroker kit in it. If he would have mentioned that i needed to put a new cam in it i would have..that wouldnt have been but a few more hundred bucks. If i would have known that the lifters needed to go back the way they came out i would have def of kept them in line. I be honest with you i think that it is the rings because the spark plugs a few weeks ago when i changed them had oil all around them. Also the valve cover breather blows oil out like crazy on the drivers side which it didnt do before i rebuilt it. It also has afr aluminum heads by the way. Thanks for all your input and help. Im going to go back and redo the compression check and see what it turns out to be. Thanks again.


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## GoldDot40 (Jun 21, 2009)

Easiest thing you can do is remove the valve covers. 'Wiggle' each and every rocker arm to feel for excess 'looseness'. If you find any...it's a tell tell sign that you lost your cam. Don't take this the wrong way, but if you spent $3K and you didn't get a new cam AND lifters.....along with a thorough inspection of your cylinder heads, then you got shafted. Also, if the engine builder didn't point out that you needed to replace your cam....he doesn't need to be building engines....period. That's sloppy work if I've ever seen it.

And as much money as you poured into everything else.....why did you skimp on the rocker arms? Scorpion is known for being cheap and fragile. You should have opted for Comp Magnums or Crower rocker arms. (Scorpion reportedly just bought out the newly 'out-of-business' Crane Cams...so hopefully their quality will improve)

Also, did you break in the new lifters? Anytime you replace the cam and/or lifters, you HAVE to break it in properly when using a flat tappet camshaft. This has to be done before it's ever driven. You have to start the engine and set the rpm to 2000-2500 for AT LEAST 20 minutes continuously. The engine is not supposed to be cut off or idle within this 20 minute period.

Another thing is what type of oil did you pour in initially? If you didn't use an oil that has high concentration of zinc/phosphorous, then it's likely your cam is flat. These newer oils have had the ZDDP (zinc/phosphorous) greatly reduced in order to be used in newer vehicles. You either HAVE to use an oil that still has higher amounts of ZDDP or pour in a ZDDP supplement. Motor oils that still contain optimum amounts of this stuff include Valvoline VR1 Racing oil (off-road use only) formula, Joe Gibbs Racing oil, Kendall Racing oil, etc.


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## Slug-Gunner (Jun 21, 2009)

*Do a "Cylinder Leak-Down Test"....*



Georgiadawgs78 said:


> Well I took to hops speed shop and let him do all the work he asked me what the oil pressure was running and i told him what it was when it was idling and he said that it had plenty of pressure. I took him every piece of the motor and told him what was up and he took it from there. He never said that I needed a new cam or I would have spent the money in the first place. I trusted him that he knew what he was doing and would fix it up right. I didnt give the motor straight heck. I hardly ever give it heck and especially didnt give it heck when I first got it back in the jeep. I didnt have the carburetor butterfly held open all the way so I will try that and see what the readings are. Maybe that was the problem a little but either way it still isnt right. The heads were trued up and the block was decked. The motor is in the 70's model and I have no clue how many miles were on it due to the speedometer wasnt hooked up. But i had put around 850 miles on it. It has scorpion 1.6 roller rockers with a crowler cam. Vic jr edelbock aluminum intake with holley aed carb (Think its a 750 but not sure) It has a double timing chain and as far as I know he didnt replace it or the gears. I was present for the final assembly and start up. Again i wasnt trying to save money if i was i wouldnt have put an all forged stroker kit in it. If he would have mentioned that i needed to put a new cam in it i would have..that wouldnt have been but a few more hundred bucks. If i would have known that the lifters needed to go back the way they came out i would have def of kept them in line. I be honest with you i think that it is the rings because the spark plugs a few weeks ago when i changed them had oil all around them. Also the valve cover breather blows oil out like crazy on the drivers side which it didnt do before i rebuilt it. It also has afr aluminum heads by the way. Thanks for all your input and help. Im going to go back and redo the compression check and see what it turns out to be. Thanks again.



EDIT:  Rewrite to correct misread input info.
(_Bassquatch_ was posting while I was writing this.)

Big D,
You stated in your OP that you had 'cracked a cylinder'. How was that 'repaired'? Was a 'cylinder sleeve' installed - and if so, what type? Did you 'bore' out the cylinders or leave them at stock bore diameter? Were all cylinders 'resleeved' or only the bad one? Were ALL the cylinder bores 'magna-fluxed' for cracks? (If one was 'cracked' others may have had 'hidden/invisible to the eye' cracks too.)

From what I can gather from your comments, the engine had been previously 'rebuilt' or at least 'modified'. You hadn't stated earlier that it had 'roller-tappet' rocker arms  in it.... if paired with ROLLER TAPPETS,  that may have 'saved you' (hopefully), if the cam was pre-lubed properly. A 'roller-tappet' cam isn't as 'critical' in the 'run-in break-in' as 'flat-tappet cams' are. That is, of course, if the previous lifters WERE ALSO 'ROLLER-TAPPET' LIFTERS! If the 'old lifters' were 'flat-tappet' lifters, he screwed up by not changing the cam. _If the 'new lifters' were FLAT TAPPET LIFTERS, he screwed up BIG TIME._ "Run-in period" wouldn't have mattered if he paired on 'old flat-tappet camshaft' with a new set of 'flat-tappet lifters'..... IT WOULD HAVE FAILED EVENTUALLY ANYWAY! Please clarify for us what type cam, lifters, etc. were used before and after.

Do you know the 'lift specs' for your camshaft? Not really needed, just 'helpful'. Pull your valve covers and use a dial-indicator set up to measure the 'amount of lift' at the valve-stem end of the rocker arm. It will have to be relocated and 'zeroed' for each new measurement. At each rocker arm, rotate the engine through TWO revolutions and measure the total amount of lift present for each rocker arm. Note which ones are for exhaust or intake BY CYLINDER #. When finished, compare all of the exhaust and intake readings WITH EACH OTHER for each separate cylinder. All of the intake and all the exhaust 'lift' measurements should be approximately EQUAL._ Any LARGE VARIATIONS will indicate WORN LOBES ON THE CAMSHAFT._ If all are within .020-.050" of each respective intake or exhaust measurement, then the camshaft is most likely NOT A PROBLEM.

OK, here's what to do on the 'compression test' to help determine if the 'rings are a problem'. First, I hope you are using a 'screw-in' type compression tester and not one of the rubber-tipped hand held ones. Block, or use a bungi-cord to hold the carburetor open to WOT during all test measurements and if possible, disable coil by disconnecting + lead to coil and tape it off.

1. Try to run engine first and get it 'warmed up' and oil circulation to all engine components.

2. Remove ALL spark plugs and disable coil and open carb butterfly.

3. Check compression on each cylinder at least TWICE and allow engine to turn over for minimum of 6 revolutions or 'hits' on compression gauge. Try to notice what the initial 'hit' reading is on the first compression stroke. Write each reading down in separate columns.

Now, we're going to do a 'wet' compression test and repeat the whole test again. This time, as you get ready to measure each cylinder squirt about 1-2 oz or engine oil into the cylinder being measured and turn the engine over for a few revolutions to distribute this oil around the cylinder walls (seals the rings). It is a good idea to put a rag around the spark plug hole to catch any 'oil spray' that might be ejected out on the compression strokes.

1. Screw the compression tester into THAT CYLINDER PLUG HOLE and do the compression test. Write down these readings (with a 'W' in front of the #s.

2. Repeat for each cylinder.

3. Compare your 'dry' readings to your 'wet' readings for each cylinder.

If the readings that were previously LOW for the 'dry' readings are now comparable to the other cylinders or have increased considerably, THE RINGS WERE CAUSING THE LOW COMPRESSION READINGS PREVIOUSLY.

If the reading _all_ INCREASE SLIGHTLY, but the previously LOW READING cylinders are still considerably LOWER than all other cylinders, VALVES OR VALVE SEATS are most likely the problem. (or head gasket between previously mentioned cylinders)

By doing both the wet/dry compression test AND using a dial-indicator to measure 'valve-lift', you can pretty much tell where your problem is (cylinders/rings or heads/valves or camshaft). 

As regards the oil pump, I will NEVER TRUST a newly rebuilt engine to an 'OLD' OIL PUMP (that I don't know the EXACT AGE OF). It may have had 'good pressure' before, but do you REALLY WANT TO TRUST IT WITH $3k+ of NEW BOTTOM END PARTS? Especially, considering and comparing the actual cost of a NEW OIL PUMP when you're already doing the 'labor' anyway. It's just 'the way I think' about such things.  

BTW:
Was the oil pump PROPERLY PRIMED before 'initial' engine startup? (or gear cavity filled with Vaseline)

Hope this helps you find your problem.

Maybe _HGM_ or _Bassquatch_ can give their opinions too....
_Bassquatch_ - good point on high ZDDP content break in oil and 'quick-check' of rocker arms for camshaft damage.


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## Georgiadawgs78 (Jun 22, 2009)

Bassquatch said:


> Easiest thing you can do is remove the valve covers. 'Wiggle' each and every rocker arm to feel for excess 'looseness'. If you find any...it's a tell tell sign that you lost your cam. Don't take this the wrong way, but if you spent $3K and you didn't get a new cam AND lifters.....along with a thorough inspection of your cylinder heads, then you got shafted. Also, if the engine builder didn't point out that you needed to replace your cam....he doesn't need to be building engines....period. That's sloppy work if I've ever seen it.
> 
> And as much money as you poured into everything else.....why did you skimp on the rocker arms? Scorpion is known for being cheap and fragile. You should have opted for Comp Magnums or Crower rocker arms. (Scorpion reportedly just bought out the newly 'out-of-business' Crane Cams...so hopefully their quality will improve)
> 
> ...



I removed the valve cover yesterday and the rocker arms have a little side to side wiggle when they are all the way up but none on the way down. Also the push rods can be twisted or turned when they are all the way up. I called the fella at the speed shop and he told me to check and make sure that I could turn all the push rods when they were all the way up and the pressure was off; this being that if I couldnt turn them that they were to tight and needed some adjustment. It did go for a break in period to let everything seat after it was properly timed...but im not sure of the exact time but it was for atleast 10 minutes. The motor oil was just regular as far as i know. I think 20w50 if im not mistaken but im not quite sure but he said dont run nothing but he said to run only that oil in it. I did run the valvoline vr1 racing oil in it before hand though. Thanks for your help


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## Georgiadawgs78 (Jun 22, 2009)

Slug-Gunner said:


> EDIT:  Rewrite to correct misread input info.
> (_Bassquatch_ was posting while I was writing this.)
> 
> Big D,
> ...



The number 5 cylinder was cracked. It was honed and sleeved. That is the only cylinder that was touched. The motor is already bored .040 over. He said at first he wasnt sure if the cylinder wall was going to be thick enough but it wound up being ok. He supposively checked to make sure that there was no more cracks in any of the other cylinders. It was pretty apparent that that one was cracked do to the scarring on the top of the piston. As far as i know its not mixing oil and water. It would be pretty obvious when I pulled the valve cover off. The oil seemed clean, ive checked the oil when it was hot and there was not sign of milky water/oil mix!

On to the cam. Im not exactly sure about the new lifters...I never seen the new lifters that were put in. But i just looked on the internet and i am pretty sure the previous lifters were flat tappet. They were solid on both sides with no rollers on the bottom. I did have all the specs on the cam when i pulled it i ran the numbers and its a crower cam but i lost the sheet of paper some where down the line. 

Im def going to try a wet comp test on it...I already thought that would be a good idea.  And im def using the screw in type and not the other kind you mentioned. Previously i turned it over four times...so should i just do it four times on the wet test or go back and do a dry and wet test with 6 licks each. Seems to get a comparable number they would have to be the same. Also i will try and get the lift measure...see if i can find a dial and maybe someone that knows how to do that because im not sure i know how. Havent seen it done or done it myself.

And if i could have went back i would have replaced the oil pump and cam and everything but as i said i didnt realize i needed to but im probably going to just pull the motor and replace the cam and everything. Anybody have a opinion on which cam i need to go with. Im going to take a picture of the rocker arms and everything to see what you think. 

Also what would cause the oil to blow out of the valve cover breather. Im thinking that the smoke when first cranked, blowing oil out of the breather, and some oil on the spark plugs would seem to put it back to the rings.

Also what do you think if i drained the oil to see if there is a considerable amount of metal shavings in the oil? Seems to me that that would be a dead give away that the cam/lifters were ate up.

Thanks again for everybodys help i really appreciate it!!!


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## Georgiadawgs78 (Jun 22, 2009)

*Pictures of rockers*

Here are some pictures of the motor


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## rayjay (Jun 24, 2009)

Good grief. You have 8000 rpm parts in a 4000 rpm application.

You might as well pull the motor and get it over with.


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## Slug-Gunner (Jun 24, 2009)

*Short reply....*

Just a 'quick reply'. I will give a more detailed answer later tonight.

First question, what is the damage shown to the left-front (driver's side) of the intake manifold in the top picture (lower-right on picture). IT IS 'GOUGED' and looks like it was dropped or dragged on the concrete.  How about posting some more photos of the entire engine and engine compartment area so we can see what all has been done to this engine?

"Blow-back" out the oil filler is most likely due to air loss in the cylinders during 'compression stroke'. This could be due to 'ring failure' or 'rings not seated yet', but could also be due to ANOTHER CRACKED CYLINDER WALL TOO.  It wouldn't necessarily show 'water in oil' unless it was cracked in a WATER-JACKET area.... MOST LIKELY ONLY WITHIN CRANKCASE OIL-GALLERY AREA.
If the engine doesn't have a PCV system, it should have an 'oil breather' type oil filler cap or  some means to relieve 'crankcase pressure' build-up.

Just my 'personal opinion', but you 'half-stepped' again on only sleeving ONE CYLINDER. You had NO KNOWLEDGE of the condition of the remaining cylinder walls without a "MAGNUFLUX TEST" being done. You had NO PREVIOUS KNOWLEDGE of exactly WHAT HAD BEEN DONE TO THIS ENGINE BEFORE YOU ACQUIRED THE VEHICLE. Someone obviously tried to make high-performance 'modifications' to this engine, based on your limited pictures and description. Whether these were done PROPERLY or OF UNKNOWN QUALITY is not known. The cylinder walls may have already been TOO THIN.... your putting the 'stroker kit' in it, would have increased the 'compression ratio' and put additional 'strain on the cylinder walls'. Adequate oil lubrication IS ESSENTIAL for the cylinder wall on a 'stroker engine'. If a rod was installed incorrectly (facing wrong direction), it would be directing the 'oil spray hole' in the WRONG DIRECTION and that cylinder would LACK ADEQUATE LUBRICATION.  You'll only know that by doing a complete 'tear-down'.

Draining the oil would NOT SHOW ADEQUATE contamination or bearing failure results.... You would need to drop the oil pan and check the deposits in the bottom of the oil pan.

 Draw an 'oil sample' and have a DETAILED _USED OIL ANALYSIS_ done on it by a reputable company. These can be found by going to the following web site - 'Bob is the Oil Guy' - this web site will tell you more about oil than you ever thought possible. Read over and 'research' the various brand oils in the "Used Oil Analysis - Test Results" section. Use the 'home page' sidebar titles to read about all the aspects of lubrication and oils.

ADDED EDIT:
Always have WITNESSES PRESENT and TAKE PLENTY OF PHOTOS during any disassembly or checks you make yourself. Keep 'DETAILED RECORDS' of anything you do (witnessed). You may need all this info and witnesses later if you end up 'in court' over problems that may come up later trying to get his 'failure' resolved (especially if the 'mechanic' denies responsibility or tries to use the fact that you DID ANY DISASSEMBLY TO DETERMINE THE CAUSE and not let him do it).  _GET THAT "USED OIL ANALYSIS" DONE ASAP_!

Hope this helps.
_
BTW:
I have over 10 years experience in building and maintaining just HIGH-PERFORMANCE RACING ENGINES during the '60s-70s "Muscle-Car Era". You learned REAL FAST that 'half-stepping' usually resulted in engine failure and extra WASTED $$$ IN "DOING IT AGAIN"!_

I will 'break down' your last post in a later new post or ADDED EDIT to this one.


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## 7Mag Hunter (Jun 24, 2009)

My guess would be the heads...Bent valves or worn guides...
Possibly bent pushrods...
Both could result in loss of compression...
If deck height was not carefully checked or high lift cam with
flattop pistons "could" result in slight valve/piston collision...
High lift rockers  increase cam lift and could be a contributing
factor...Since your compression readings seem to be all over the
place I doubt a piston ring problem....
I have built 2 SB 383 strokers for trucks and always use dished
pistons and mild cams....
Pull the push rods from the weak cylinders and see if they are bent..
Let us know what you find...


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## Slug-Gunner (Jun 24, 2009)

*I agree !!!!*



7Mag Hunter said:


> My guess would be the heads...Bent valves or worn guides...
> Possibly bent pushrods...
> Both could result in loss of compression...
> If deck height was not carefully checked or high lift cam with
> ...




I fully agree and concur.... _7Mag Hunter_ makes some EXCELLENT points for consideration. Especially, since the 'heads werent touched' (except rocker arm modifications) and/or possibly taken into consideration for _ADEQUATE 'VALVE-PISTON CLEARANCE' TOLERANCES._

Check push-rods for 'bent' damage as suggested (remove and 'roll' on known flat surface) and measure that 'valve-lift' so you can compare it later against 'deck-height' clearance between open valve and piston top surface.

Were these 'flat-topped' high compression pistons or did they have 'dished-tops' or 'valve clearance cut-outs' recessed into them?

Possible 'sources of problems' are coming up THAT SHOULD HAVE ALL BEEN CONSIDERED (and suggestions made/eliminated) PRIOR TO or DURING ENGINE ASSEMBLY by an 'experienced' high-performance engine builder.

The 'plot' thickens.     -----    you >  < engine builder


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## hawgrider1200 (Jun 24, 2009)

I can't believe anybody put new pistons in old cylinders without boring the cylinders to the pistons. Somebody said you did not need to worry about the rings being misaligned, but you do. My youngest brother had bought an engine from a feller who had just rebuilt it and it wouldn't run right, he took it apart and all that was wrong with it was rings with the gaps lined up with each other. When he put it back together, It ran like a scalded dawg.


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## Georgiadawgs78 (Jun 24, 2009)

I will post real quick myself on a few things since im at work. 
1) All 8 cylinders were honed but only one was sleeved
2) I dont know what is up with the picture put the intake manifold fine...must just be something in the picture. I have some things sitting on top of the intake.
3) Used the same size push rods and style pistons. They have the valve reliefs on top...NOT flat top or dish style
4) Im thinking that its best that I dont do any breaking down and investigating of the engine myself that way it cant get blamed on me for messing something up.
5) The machine shop man never said or mentioned anything about needing to sleeve all of the cylinders.
6) I took quite a few pictures but they are going to have to be resized...it takes me a while to figure out how to do that..but they are of the whole engine compartment and what not. 
7) Im going to go back and check the dry compression and then do a wet compression check this weekend. Too busy with work right now plus i need someone else to help as well.
8) Again thanks for all  the help and hopefully i can figure everything out pretty soon. Im going to do those compression checks and then start unhooking and pulling everything out to get it ready to pull the engine AGAIN.


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## Georgiadawgs78 (Jun 24, 2009)

rayjay said:


> Good grief. You have 8000 rpm parts in a 4000 rpm application.
> 
> You might as well pull the motor and get it over with.



Elaborate a little if you could. Im not sure if i get what you are saying. Thanks!


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## Georgiadawgs78 (Jun 24, 2009)

*Used oil analysis*

Hey slug gunner. Where do you go to get the oil analyzed? I went to the website but didnt see anything to where you could send the oil to? Do they do it or do i have to get it done locally. This is the first time ive heard of getting your oil analyzed. Thanks
Dexter


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## Slug-Gunner (Jun 24, 2009)

Georgiadawgs78 said:


> Hey slug gunner. Where do you go to get the oil analyzed? I went to the website but didnt see anything to where you could send the oil to? Do they do it or do i have to get it done locally. This is the first time ive heard of getting your oil analyzed. Thanks
> Dexter




GD78,
Later this evening or in the morning, I'll check the "BITOG" web site and post some UOA site links or links to discussions on the web site. 

Take a look at the 'sidebar' articles when you have time this evening for more info on oil and WHAT "UOA" oil analysis is. There is a 'link' near the bottom of the 'sidebar' article on UOA that will take you to ACTUAL TEST RESULTS of various brands of commercially available oils. It shows that their REALLY IS A DIFFERENCE in the 'protection factor' of different brands of oils.

It also explains about the ZDDP levels in various brands of oils too - along with what other 'additives' do for various aspects of oil and 'lubrication characteristics' = a lot of USEFUL KNOWLEDGE.

ADDED INFO:
Many on these forums are still basing their 'oil knowledge' on the same oils that their fathers used in the '60s-'70s.  Modern oils and especially some of the 'synthetic' oils being produced ARE FAR SUPERIOR now than ever before. The statement that many make.... like _"Oil is oil."_ or "_All oils are the same as long as they meet the mfgs rated standards."_ COULD NOT BE FURTHER FROM THE TRUTH than now between different brands available - even more so when you compare conventional 'dino' oils to the higher quality SYNTHETIC BASED OILS.


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## GoldDot40 (Jun 24, 2009)

Georgiadawgs78 said:


> Elaborate a little if you could. Im not sure if i get what you are saying. Thanks!



What he's saying is, you have certain parts that are usually used in an all out high revving racing application. 

The full roller rockers = overkill
Stud girdle = overkill
Edelbrock Victor Jr intake manifold = overkill
etc 
etc
etc

Of course you never stated what kind of stuff you planned on doing with this engine. Is it race engine? I noticed it's in a truck....you planning on hauling/towing anything? Off-roading? All the high performance parts CAN actually hurt you in off-idle/low rpm torque....which is usually where it matters the most in a heavy pickup truck. You live and you learn. I hope you get it all figured out. Like Slug-Gunner, I've been hotrodding for quite a few years....and I have built several stout engines for friends, family, and myself over the years.

Engine components will only work as they are designed if everything else is compatible. Everything must compliment everything else. When you have a well balanced engine, planned and built for exactly what you intend to do with it....it will definitely leave a smile on your face. 

 Feel free to PM me anytime if you ever want advice on compatible parts to use in an engine.....especially Chevrolets.


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## 7Mag Hunter (Jun 24, 2009)

Lets cut him some slack....He is asking for help, not criticism...
With forged crank/rods and aluminum heads he does have a
good bottom end for high revs and top end for breathing....
Things we don't know are the rear end gear ratio and cam lift
and duration....
While most stroker motors are built for low end torque, they
can also rev to well over 6 grand with the right parts...
I also use roller rockers and full float pistons on my strokers....Just
a little less friction....No stud girdle tho...


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## Slug-Gunner (Jun 24, 2009)

*Ring "END-GAP" Issues....*



hawgrider1200 said:


> I can't believe anybody put new pistons in old cylinders without boring the cylinders to the pistons. Somebody said you did not need to worry about the rings being misaligned, but you do. My youngest brother had bought an engine from a feller who had just rebuilt it and it wouldn't run right, he took it apart and all that was wrong with it was rings with the gaps lined up with each other. When he put it back together, It ran like a scalded dawg.



Just a little 'added info' to _hawgrider1200's_ post.

Although the recommended 'gap spacing' between adjoining ring grooves is between 120-180 degrees apart from each other and the next ring, the ring "END-GAP" can be EXTREMELY CRITICAL (especially with a bore that WAS already 0.040" over and has only been re-honed prior to assembly). If the ring "END-GAP" is NOT ADEQUATE, it can lead to either/both ring failure (cracked rings) or GLAZED CYLINDER WALLS during initial engine run-in.  EACH RING must be individually fitted into the cylinder (that it will be going into) and 'squared-up' and the "END-GAP" _INDIVIDUALLY ADJUSTED TO THE PROPER CLEARANCES OR GAP_. It then must be assembled onto the proper piston that IS MARKED AND DESIGNATED TO GO INTO THAT CYLINDER BORE. This is EVEN MORE CRITICAL if the engine is a HIGH-PERFORMANCE ENGINE.

Just MORE INFO for consideration.


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## Georgiadawgs78 (Jun 25, 2009)

This Jeep originally came out of Florida where it was sand dragged for a season. A fella out of Dalton, GA traded two broncos and some cash for it. Drove it on the weekends and maybe once  a week to work. Didnt race it or drag it or anything. I seen it in autotrader after looking for a jeep for about 4 months. Drove up looked at it and bought it. My sole intentions for this thing is to just drive it on the weekends and a toy. I wanted to drag it a few times to see what it had and could do. This thing HAD some torque and would probably hang with most anything in the 8th of a mile...but anyways the people at atlanta motor speedway said that i had to have a helmet full leather suit and arm restraints. Could have had the helmet and arm restraints but dont have a leather suit so i just said the heck with it. I would love to sand drag it but thats not something that happens around here. Its def not going to see any mud. The top end is exactly like it is when i bought it. I just modified the bottom end since i had to anyways with the cracked cylinder. Thanks again for all the help i really appreciate it!!! Im hoping to get started on it in the morning and give you some more compression numbers.


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## Georgiadawgs78 (Jun 25, 2009)

4:10 gears in the rear end is what the previous owner stated. Runs right around 3000 rpms at 60mph


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## Georgiadawgs78 (Jun 25, 2009)

*Pics*

Here are a few more pictures so you can get an idea of what we are working with.
Dexter


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## Georgiadawgs78 (Jun 27, 2009)

*Dry and Wet Compression Check*

Okay so i finally got the dry and wet compression done today. Just in time because it started raining while i was cleaning up. I ran the test atleast twice on each cylinder as long as the two test were right there with each other and i turned the engine over six times each time. Also with the carb held wide open.

So here is the results.....!!!

DRY TEST

8......20;20------------7......235;235
6......135;10;30-------5......120;115
4......230;230---------3.......250;250
2......235;240---------1.......230;240

*NOTE* Number six cylinder is very inconsitent. It hits what ever it want when it wants but those numbers represent right around what it hits each time.

WET TEST


8......30;0------------7......290;285
6......50;0------------5......120;135
4......295;290--------3.......300+;295
2......280;275--------1.......300+;300+

*Note* The number eight cylinder hit on the first run on the first turn of the engine and thats it. The next few test it didnt hit nothing. Same as cylinder six. it hit 50 psi with the first turn of the motor but the next five didnt move the dial. All runs after yielded 0 as well. CYLINDER THREE barely hit past 300 on the first run. CYLINDER ONE hit way over 300 on the first run... around the 330 or so range i would guess but it only reads up to 300. The second run hit prob around 310 to 315.

So heres the tests....what do yall think? I feel like the compression on the wet test are a little high....? I felt like 225 would be a good cylinder compression for the motor but im not an engine builder so im not sure. I do know that something is def wrong and that the compression did improve on almost every cylinder which would seem to me that something isnt quite right with the rings.


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## Backlasher82 (Jun 27, 2009)

I wouldn't worry too much about the high compression numbers you got on the wet test, I think you put too much oil in the cylinders.

A leakdown test will tell you the problem with the 20 psi cylinder but I'm betting valve leakage unless you have a big hole in the piston dome. 

Good luck and keep us posted.


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## Georgiadawgs78 (Jun 28, 2009)

Backlasher82 said:


> I wouldn't worry too much about the high compression numbers you got on the wet test, I think you put too much oil in the cylinders.
> 
> A leakdown test will tell you the problem with the 20 psi cylinder but I'm betting valve leakage unless you have a big hole in the piston dome.
> 
> Good luck and keep us posted.



Well lets hope so. I had a 16oz bottle of oil that i used and didnt quite use half of it. I turned the engine over about 15 times on each cylinder. First 10 i would leave the rag over the spark plug hole then leave it off to get any excess out. I will be pulling the motor sometime next week since i will be gone all this week in meriwether county on a big erosion control job. The weekend is the fourth so i will start on it and should have it pulled and ready to send back to the machine shop. Im thinking the number 5 cylinder is def a valve because that one is the one that had some water damage on the valves. But i have no clue on the 6 and 8 cylinders unless its a blowed head gasket? Should still have a lot more psi though. Doesnt make much sense since it only hit the first time and would show any compression the rest of the tries. Thought it might be the compression tool so i put it back on 2nd cylinder and it done fine. I will keep you posted. I just really wanted to get some good info from some people so i wouldnt get the run around at the machine shop. Im probably going to go ahead and put a cam and a new set of lifters on it. Get a valve job done and hope that the pistons dont have a hole in it. 

LETS SAY THAT ONE OF THE PROBLEMS IS THAT THE LIFTERS AND CAM LOBES ARE ATE UP...Should i be resposible for that or the machine shop since he never mentioned putting a new cam in it at all. Should he have to buy the cam and lifters or should I? All he wanted was the specs for it!!! If its the rings he is def going to be fixing it. I will pay to get the valve job. Also does anybody know what type of CAM I should go back in it? I want something that hits a lick but as i stated this is just a weekend driver. I went to the night of fire tonight and was wishing I had my jeep running so i could take it over there one friday night and give her all she had. 

One more question I have is anybody familiar with an air shifter? This thing has the CO2 bottle and everything hooked up to the cheetah scs shifter and it has the rpm setting box but i think it might be missing a box or something to make it work. Just thought about it since i heard all those pro mods and dragsters with them running.

Dexter


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## Slug-Gunner (Jun 28, 2009)

*Compression Test Analysis....*



Georgiadawgs78 said:


> Okay so i finally got the dry and wet compression done today. Just in time because it started raining while i was cleaning up. I ran the test atleast twice on each cylinder as long as the two test were right there with each other and i turned the engine over six times each time. Also with the carb held wide open.
> 
> So here is the results.....!!!
> 
> ...




Dry Compression Test:
First, let's determine what is probably considered the normal 'dry compression readings' for your engine. Most techs consider that anything that is within +/- 10% of the 'average' reading is considered NORMAL. Let's say your average reading then is say 240.... that would mean that anything between about (roughly) 220-260 would be considered 'acceptable'. This means that cylinders 1-4 & 7 are 'acceptable'. Cylinder 5 is about HALF what it should be and cylinders 6 & 8 are 'extremely' LOW (adjoining). As to #6 being variable, I'll address that later.

Based on your 240 average, I would say you have about at least a 12:1 compression ratio. We would need bore x stroke and combustion chamber volume to calculate a 'true' compression ratio though. What this DOES MEAN is that you should be using 'PREMIUM' GASOLINE for fuel. If your were running REGULAR UNLEADED FUEL, you may have BURNED VALVES or possibly BURNED A HOLE IN A PISTON. This would be due to 'detonation' of the fuel charge. Did you ever notice any 'pinging' or 'knock' during moderate-to-hard acceleration?


Wet Compression Test:
First, let me explain a few things about what a 'wet test' actually accomplishes or does. By squirting at least 1-2 ounces of oil in each cylinder and then 'turning it over' to distribute the oil around the cylinder before you actually make the measurement, you are SEALING THE RINGS  & CYLINDER WALLS MORE EFFECTIVELY (especially a 'marginal/cracked ring' or glazed/lightly-scored cylinder wall). Because of the 'oil distribution' around all areas of the cylinder, some 'slight' additional sealing of the valves _may sometimes happen too_, especially if they are only 'marginal' on their sealing of the valve/seat face.

This 'effective sealing' is clearly indicated on cylinders 1, 3, 4, & 7 and pretty good on 2. I don't see any real problem on these cylinders and a reading of near 300 with 'high compression' is TOTALLY NORMAL. Cylinders 5, 6, & 8 show basically NO CHANGE when oil was added to the cylinders.... So I would say your problem is most likely not with the rings or cylinder walls themselves (at least not a TOTAL FAILURE). It is 'possible' that #8 may have a CRACKED PISTON TOP too.

I'm leaning towards 'bent valves' more than 'burnt valves' but I could be wrong, especially if you were using REGULAR GAS. It may be that #5 valves may have even been marginal before the engine job was done, but that could have only been verified by having done a 'vacuum test' on the heads after they were 'resurfaced'. 

The 'VACUUM TEST' is accomplished by placing the 'resurfaced' and 'reconditioned valves' assembled head on a SMOOTH, FLAT RUBBER MAT with a light coating of Vaseline on the head mating surface. Then a 'gaged vacuum' is applied to each cylinder via the spark plug hole with an adapter. This vacuum is 'held' for at least 5-10 minutes to insure that the valves SEAL PROPERLY and no leaks or cracks in the combustion chamber are present. 

Here's where I'm going to make a few "WAGs" (Wild-A__-Guesses" based on past experience. The fact that cylinders 6 & 8 are adjoining cylinders might lead me to believe that when the heads were 'trued' or 'shaved' might make me suspicious that the head was NOT PERFECTLY LEVEL WHEN THIS WAS DONE..... in effect one end (6&8 end) was taken down more than the other end (unevenly). This could have then given UNEVEN valve-piston clearance at that end, resulting in a 'slight' collision of the valves with the pistons. If the valves 'hit' the pistons this WILL BE IMMEDIATELY OBVIOUS when you pull the heads off and can see the piston tops (they will have 'impact' marks on them). The only way this theory could be determined would be to ACCURATELY MEASURE THE 'DECK HEIGHT' AT EACH COMBUSTION CHAMBER ON THE HEAD. This is something that would needed to be done by either a 'precision' automotive machinist, or someone 'skilled' and 'knowledgeable' in doing it. This LAST SUGGESTION is of course dependent on whether you have 'evidence' of valve damage or piston damage evident from the valves and pistons colliding with each other.

I was going to suggest another possibility, but it would have MOST LIKELY AFFECTED ALL VALVES IF TRUE. This would have been involving your 'new' roller rockers if they were NOT 1:1 ratio rockers. Some specialty 'roller rockers' were once available that had a greater than 1:1 ratio to give more 'lift'. This could be determined by using a dial indicator and measuring the amount of LIFT at EACH END of the rocker arm to see if they WERE EQUAL OR NOT.

Oh, to maybe expain the variable readings on #6 cylinder.... if the valve was bent JUST VERY SLIGHTLY, it might be possible that at one point in it's rotation that it JUST HAPPENED TO SEAT 'ALMOST' FULLY and cause a higher reading at that time. The opposite is sometimes true for a BURNED VALVE.... it can read higher, EXCEPT WHEN THE 'BURNED AREAS' ARE ALIGNED PERFECTLY.

Out of curiosity, what type of HEAD GASKETS were used and what was their 'thickness'? Head gasket thickness (COMPRESSED) comes into play when determining DECK HEIGHT CLEARANCES. This engine was apparently NOT "BLUE-PRINTED" before assembly to take into consideration all PREVIOUS and CURRENT MODIFICATIONS.

Only REMOVING THE HEADS will tell you what you have,but you may NOT NEED TO PULL THE WHOLE ENGINE..... YET. Depends on what you find then = condition of PISTONS & CYLINDER WALLS.

One thing that was never mentioned before.... were the VALVE STEM SEALS ever changed? Should have been!


ADDED EDIT:
Remembering our previous discussion on CHANGING THE CAMSHAFT, make sure you inspect the 'flat-tappet' lifters for what the surfaces look like AND DO NOT GET ANY SWAPPED AROUND IN DIFFERENT LOCATIONS while looking at them. If you decide to TAKE A CHANCE and leave them in, you may be back in that engine again in a year or less to change it then. If you change the camshaft, get one with an economy grind and more lower end torque curve to it to match your 'stroker' engine. 
Also, when you pull the push-rods out, take a 4x4 piece of wood about a foot long and drill 16 1/2" holes in it (8 on each side opposite each other and slightly spaced in pairs). Drill a hole in the center at one end to designate the FRONT of the engine. Put them in this block as you remove them to keep them oriented to the correct position they came from. You can do something similar for the lifters, but use a 2x6 and drill 1" or larger holes for them. These holes SHOULD NOT go all the way thru the boards being drilled.

Hope this helps.

PS:
Collect about 6 ounces of oil as an 'oil sample' from the engine BEFORE ANY DISASSEMBLY - IN A 'CLEAN' CONTAINER OR JAR.

Out of curiosity, what did you happen to pay for your jeep. If you ever happen to want to sell it, I might be interested IF THE PRICE IS RIGHT.


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## redneckcamo (Jun 28, 2009)

well after reading thru this thread at the various information you have given it sounds like an engine a young dude built around here a few years ago ........ he ended up compressing the rings in the grooves of the pistons (they were forged too) due too severe detonation in the combustion chambers ..... high compression an low octane fuel/pump gas ! 

when you tear it down... I bet the rings are squeezed in the grooves of the pistons !!


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## Georgiadawgs78 (Jun 28, 2009)

I might have ran some regular gasoline back when gas was high and i was pressed for money but most of the time I would run either premium or 110. The funny thing is that the machine shop cranked it up and tuned it up and everything with regular low grade gas and then set there and told me that it would be fine. The fella i bought it from told me to either run high grade or racing fuel in it. So up until racing fuel went up to $8 dollars a gallon i ran it. I havent never heard it knock or ping but it is pretty loud as well. Im probably going to figure out some kind of exhaust to quiten it down a bit. The valve seat seals were not replaced so i will add that to the list of things i need to do.


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## Georgiadawgs78 (Jul 9, 2009)

Ok fellas i got everything unhooked and ready to pull the motor out in the morning to take back to the machine shop. Just going to see if yall had any suggestions on what type/brand of cam, lifters, and oil pump to put back in it. Im going to take a few more pics and pull the oil pan and what not. Might pull a head to see what she is looking like in there.


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## GoldDot40 (Jul 10, 2009)

Georgiadawgs78 said:


> Ok fellas i got everything unhooked and ready to pull the motor out in the morning to take back to the machine shop. Just going to see if yall had any suggestions on what type/brand of cam, lifters, and oil pump to put back in it. Im going to take a few more pics and pull the oil pan and what not. Might pull a head to see what she is looking like in there.



I'd be glad to recommend some stuff for you....but I'd need to know what exactly you're looking for from the engine....performance wise. You going to play in the mud, race it, or just cruise in it?


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## Slug-Gunner (Jul 11, 2009)

*Talk to "Tech Support" Specialists....*

I've been out of the 'Performance Engine Building' for too long to know what's currently available. I'd suggest sitting down and making a list of all the current engine modifications you have on your engine - bore x stroke and engine cubic inch capacity; type of crankshaft and pistons; type of heads and intake manifold (yours is a "PERFORMER AIR-GAP® & RPM AIR-GAP® MANIFOLD")  .... EVERYTHING YOU HAVE ON IT (to include transmission mods and rear axle ratios, tire sizes, etc.).

Then call BOTH Edelbrock and Summit Racing and talk to one of their "Tech Support Specialist" _(click on names to go to 'links')_ and tell them what you want to do with your Jeep when finished (What type of "performance" you want.) They are 'experts' in this field and can give you the best info on the type of cam design that is best for your needs THAT WILL COMPLIMENT YOUR CURRENT ENGINE MODS. 

Since most of your upper engine components are Edelbrock, it might be best to stick with that brand since many of their products are engineered and designed to 'compliment each other'.


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## Georgiadawgs78 (Jul 14, 2009)

Well finally figured out what was wrong with it. The lobes for cylinders 6 and 8 were grounded off. That would leave only cylinder 5 left that is totally out of whack and i believe that the valves arent seating properly since they were scarred up by water in the cylinder when the number 5 cylinder cracked. I dont believe he has tore the motor down to check the rings or pistons since he couldnt tell me which valves were scarred up. So i got him to give me the numbers of the heads and this is what he come up with. Imagine a box with stuff written in the corners and middle. 
Top left has a 5; Top right has a 24; Bottom left has a S; Bottom right has a 3; in the dead middle is a 02; and in between the 5 and S is a J. What do yall make of this?


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## Slug-Gunner (Jul 14, 2009)

*Contact the Manufacturer to Decode #'s.....*



Georgiadawgs78 said:


> Well finally figured out what was wrong with it. The lobes for cylinders 6 and 8 were grounded off. That would leave only cylinder 5 left that is totally out of whack and i believe that the valves arent seating properly since they were scarred up by water in the cylinder when the number 5 cylinder cracked. I dont believe he has tore the motor down to check the rings or pistons since he couldnt tell me which valves were scarred up. So i got him to give me the numbers of the heads and this is what he come up with. Imagine a box with stuff written in the corners and middle.
> _
> Top left has a 5; Top right has a 24; Bottom left has a S; Bottom right has a 3; in the dead middle is a 02; and in between the 5 and S is a J. What do yall make of this?
> _



They are most likely some form of manufacturer's assembly line 'run code'. You need to contact the manufacturer of your heads and ask their 'technical support' personnel. I reread over this thread and couldn't find where you mentioned what brand of heads you had, but thought they were Edelbrock. 

Let us know what you find out.


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## Georgiadawgs78 (Jul 14, 2009)

Slug-Gunner said:


> I reread over this thread and couldn't find where you mentioned what brand of heads you had, but thought they were Edelbrock.
> 
> Let us know what you find out.



Hey the heads are AFR aluminum heads. Just trying to pull some specs for them and see what size they were. I emailed AFR's tech with the information maybe they can get back with me on it. What do yall think would be a good ball park figure on a valve job on my heads. I know there is many diff types of valve jobs with the degreeing and stuff just thought yall might be able to give me some type of insight on this. Thanks for all of yalls help. Im going to try and get a video up when i get it back running and stuff.


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## boneboy96 (Jul 14, 2009)

if you ever get this back up and running...I wanna see it...sounds like it's going to smoke the tires!


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## Slug-Gunner (Jul 14, 2009)

*Use 'Google Search' to "Learn All You Can"....*

I suggest you start using 'Google Search' to start "Learning All You Can" about your 383 cu in engine and what modifications you have and can do to it.

Here are a couple to start with:

383 cu in Frequently Asked Questions 
(Read all of this.... especially the LAST PART on cams and oil pumps.)

383 Stroker Engines (put on a bib to catch your drool) 

Air-Flow Research Web Site

_You need to find out what the 'compression chamber' capacity of your heads are so you can calculate your "Compression Ratio" properly._



Since you've already had one "bad experience" from 'half-stepping' on your engine rebuilding, here are a few suggestions on your heads.

1.  Once the heads are disassembled, have them "magna-flux" tested for any cracks or irregularities, especially around the valve guides and valve seats.

2.  Other than having the valves and seats "reground and reseated", check the valve guides for wear.

3.  Install 'high-performance' teflon style valve stem seals.

4.  Have the valve springs checked for proper spring tension and height (static and under 'max lift' compression).

5.  Once the heads are completely assembled 'vacuum test' them as described in an earlier post.


Have you decided yet whether you are going to go with a 'flat-tappet' cam & lifter setup or go with a 'roller-cam & lifter' setup?

Check around as suggested earlier for recommendations with Summit Racing or Edelbrock tech support on 'matching' camshaft grind to your needs and current engine mods. Keep in mind the the 'higher' the performance specs, the rougher it will idle and be LESS STREET DRIVABLE on a 'daily-driver basis'. You can most likely go with a grind that will give you better 'low-end torque' and better fuel economy, yet will still have the 'get-up & go' when you want it to.

"Hind-sight is 20/20".... don't get hit with a 2x4 to 'learn twice'. Do your 'research' to make sure you get everything done right this time.

DON'T FORGET THE 20-30 MINUTE 'RUN-IN' OF THE NEW CAMSHAFT AND LIFTERS.... unless you want to do it again in a few months. Remember, don't let it get below 1800 rpm, but not over 2500 rpm during this period.... and use PREMIUM FUEL WHILE DOING IT.

AND....

Bassquatch said:


> Another thing is what type of oil did you pour in initially? If you didn't use an oil that has high concentration of zinc/phosphorous, then it's likely your cam is flat. These newer oils have had the ZDDP (zinc/phosphorous) greatly reduced in order to be used in newer vehicles. You either HAVE to use an oil that still has higher amounts of ZDDP or pour in a ZDDP supplement. Motor oils that still contain optimum amounts of this stuff include Valvoline VR1 Racing oil (off-road use only) formula, Joe Gibbs Racing oil, Kendall Racing oil, etc.
> 
> Also, did you break in the new lifters? Anytime you replace the cam and/or lifters, you HAVE to break it in properly when using a flat tappet camshaft. This has to be done before it's ever driven. You have to start the engine and set the rpm to 2000-2500 for AT LEAST 20 minutes continuously. The engine is not supposed to be cut off or idle within this 20 minute period.


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## Georgiadawgs78 (Jul 14, 2009)

I suggest you start using 'Google Search' to start "Learning All You Can" about your 383 cu in engine and what modifications you have and can do to it. Ive been doing a ton of looking on the web and seeing what people are saying about different set ups and what they are turning on the dyno.

Here are a couple to start with:

383 cu in Frequently Asked Questions 
(Read all of this.... especially the LAST PART on cams and oil pumps.) That is a pretty interesting and useful website. Thanks.

383 Stroker Engines (put on a bib to catch your drool) Ive actually looked at those motors and what they were running in them.

Air-Flow Research Web Site

You need to find out what the 'compression chamber' capacity of your heads are so you can calculate your "Compression Ratio" properly. Im going to get the shop to calculate the ratio for me I believe, as soon as i get the specs on the cylinder heads.



Since you've already had one "bad experience" from 'half-stepping' on your engine rebuilding, here are a few suggestions on your heads.

1. Once the heads are disassembled, have them "magna-flux" tested for any cracks or irregularities, especially around the valve guides and valve seats.

2. Other than having the valves and seats "reground and reseated", check the valve guides for wear.

3. Install 'high-performance' teflon style valve stem seals.

4. Have the valve springs checked for proper spring tension and height (static and under 'max lift' compression).

5. Once the heads are completely assembled 'vacuum test' them as described in an earlier post.


Have you decided yet whether you are going to go with a 'flat-tappet' cam & lifter setup or go with a 'roller-cam & lifter' setup? Im just going to go back with the flat tappet cam since thats what was in it to start with. He said all his labor is free and that he is going to try and get the cam warrantied.

Check around as suggested earlier for recommendations with Summit Racing or Edelbrock tech support on 'matching' camshaft grind to your needs and current engine mods. Keep in mind the the 'higher' the performance specs, the rougher it will idle and be LESS STREET DRIVABLE on a 'daily-driver basis'. You can most likely go with a grind that will give you better 'low-end torque' and better fuel economy, yet will still have the 'get-up & go' when you want it to. Now with the more low end torque will i need to change the 27-2800 stall to a little lower rpm?

"Hind-sight is 20/20".... don't get hit with a 2x4 to 'learn twice'. Do your 'research' to make sure you get everything done right this time.

DON'T FORGET THE 20-30 MINUTE 'RUN-IN' OF THE NEW CAMSHAFT AND LIFTERS.... unless you want to do it again in a few months. Remember, don't let it get below 1800 rpm, but not over 2500 rpm during this period.... and use PREMIUM FUEL WHILE DOING IT. Im def going to do this with the oil additive that i bought the other day. Def cant forget that.


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## Georgiadawgs78 (Jul 14, 2009)

boneboy96 said:


> if you ever get this back up and running...I wanna see it...sounds like it's going to smoke the tires!



Oh she will be back up and running in a few weeks. I got to go out of town for the rest of the week for work and then sat i leave for the beach and wont be back for a week but when i get back im going to get it finished up and thrown back in the jeep. Im going to post a video of it on here if i can figure out how to do it. Might need someone one to teach me how to imbed a video in a post and not just a youtube link. Oh and yeah it will smoke those 39.5x18" tires with ease.


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## Eric Brooks (Jul 17, 2009)

Do a leakdown and call it a day.


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## horse2292 (Jul 17, 2009)

I have 383 that I had in a K5 and it would roast my 42's. I did the dart heads and lots of extras. Was trying to sell it but didn't get much interest. I didn't figure 1800 was bad for a 4 bolt main stroker. Post up pictures of the tear down.


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## 7Mag Hunter (Jul 17, 2009)

I have had good luck with Comp Cams 268 grind cams in
stroker motors...It is a hydraulic can with 268 degrees duration
and 454" lift...Mild but makes good low end torque...Decent mileage
too....
For a bit more mid range look at the 270 degree solid lifter cam....
Its still a streetable cam ....


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## Georgiadawgs78 (Jul 28, 2009)

Thanks again for all the replies and help. I believe Ive got everything figured out. Im going to tone her down a bit by replacing the worn crower cam http://crower.com/misc/cam_spec/cam_finder.php?part_num=00321 with a comp cam. Cant remember the exact numbers but its going to be a milder cam. 

Then im going to replace the victor jr with the Edelbrock performer rpm air gap (PN# 75014) This should add more to the bottom end.

I am also going to exchange the B&M Holeshot 3000 torque converter (PN#20413) with a B&M Holeshot 2400 (PN# 20412).

Also, I am going to go ahead and do a complete make over on the heads and check them out and get a valve job. That should pretty much have everything covered that I can think of besides an oil pump and new water pump. 

Im thinking about dressing the engine up a little bit as well with the intake being endurashine along with the valve covers. Ive heard some mixed reviews about them staining with fuel spills but i havent never had any problems with a fuel leak. 

So what do yall think...sound like a decent combination? Am I missing anything?


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## fishhead (Jul 31, 2009)

A couple of other things you need to consider. 
1. Aluminum heads can not be magnafluxed, they have to be pressure tested. Since you did not have any heating issues or water in the oil you can probably get by without having the heads pressure tested. 
2. When breaking in your new cam be sure to use the right oil. Most cam company's offer a break in additive to add to the oil. Or to be sure you can use Joe Gibbs BR oil. This oil and those additives have an increased amount of Zinc Dialkyl Dithio Phosphate (ZDDP) tat helps keep the cam rom wearing out.
3. AFR really makes some fine heads, good power and torque.


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## Georgiadawgs78 (Jul 31, 2009)

fishhead said:


> A couple of other things you need to consider.
> 1. Aluminum heads can not be magnafluxed, they have to be pressure tested. Since you did not have any heating issues or water in the oil you can probably get by without having the heads pressure tested.
> 2. When breaking in your new cam be sure to use the right oil. Most cam company's offer a break in additive to add to the oil. Or to be sure you can use Joe Gibbs BR oil. This oil and those additives have an increased amount of Zinc Dialkyl Dithio Phosphate (ZDDP) tat helps keep the cam rom wearing out.
> 3. AFR really makes some fine heads, good power and torque.




Thanks for your help...I didnt realize that aluminum heads couldnt be magnafluxed. Im def going to add a bottle of the oil additive with the ZDDP in it for the cam break in.


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## Slug-Gunner (Jul 31, 2009)

*Check With Manufacturer....*



Georgiadawgs78 said:


> Thanks for your help...I didnt realize that aluminum heads couldnt be magnafluxed. Im def going to add a bottle of the oil additive with the ZDDP in it for the cam break in.



When in doubt, GO TO THE SOURCE!

I suggest giving AFR a phone call and talk to one of their 'tech support' people about "the best method to test their heads for 'flaws'. Explain what happened with your last 'rebuild' and that you WANT TO ELIMINATE ANY POSSIBILITY OF FAILURE AGAIN. 

While you've got them on the phone, give them the model/casting #s for your heads and inquire about the cc capacity of the head's combustion chamber so you can get an accurate calculation of your compression ratio.

_ADDED COMMENT:
As a matter of fact, while you've got AFR 'tech spt' on the phone, give them the bore x stroke dimensions (or 383 cu in + .040 over) and they can probably calculate it for you in a few seconds._


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## fishhead (Aug 1, 2009)

A few other thoughts,
1. Be sure you get a very reputable machine shop to perform the valve job. Be sure to use 3 angle serdi type cutters. A lot of power can be lost very quickly by doing a poor  valve job.
2. Most reputable machine shops  check spring pressures, both open pressure and seat pressure, as part of the valve job. Also be sure to check the springs for coil bind. 
3. There are other good alternatives to the teflon valve seals. Viton is very durable, seals very well, and there is less chance of damaging the seal upon installation. 
4. Since this is a pretty serious engine there is a good chance the eads have been milled down to increase compression. The only sure way to determine this is to C.C. the heads. Most machine shops perform this operation on a regular basis.
5. If you need any advice please feel free to P.M. me and I will be glad to help.


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## Georgiadawgs78 (Aug 6, 2009)

Thanks for your help fishhead. Im actually installing the reccomended springs for the milder cam I am putting in it. We done a leak down test on all of the valves and everything was fine minus the number five intake valve. It poured...so I called afr and ordered another valve..the old one was bent. Just to give an update on what I have done so far. Checked the bottom end out and everything looked fine. Two lobes on the cam was wore completely out along with egg shaped lifters to go with them. Ordered and installed a comp extreme energy flat tappet cam and lifter set. The springs got in today and should be installed tomorrow. He ordered the valve and it should be here in a couple of days. I ordered a brand new dual plane edelbrock performer eps intake manifold with the enduroshine finish to replace the old victor jr, brand new B&M holeshot 2400 torque converter to replace the old B&M Holeshot 3000 torque converter, and I also went ahead and broke down and bought a new set of enduroshine edelbrock valve covers to match the intake. Those things are way over priced. But i did find the best prices at a company called loppers off of ebay. They didnt have the items on ebay but I called and got them ordered. Should be back together and in the jeep by next weekend.


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## fishhead (Aug 6, 2009)

Before you put  it back together be sure you check piston to valve clearance. That valve got bent somehow, better to find it now than later.


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## Georgiadawgs78 (Aug 7, 2009)

Oh yeah def. Its the same valve that the cylinder was cracked. The old piston face had some good water damage on it. Im hoping it had something to do with that!Thanks!
D


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## flatheadz (Aug 13, 2009)

I've had several problems like this. I ll bet you wiped the lobes on the cams. new motor etc, old cam, new lifter big no- no. you said motor ran great. the only thing that makes since is bent pushrods or wiped lobes. You can remove valve cover and turn motor over and watch /measure your rockers to tell if you still have proper lift. only other condition would be stuck / dropped valve. If you rebuild head ( $125). Put stainless valves in it. You can turn the Edited to Remove Profanity ----Edited to Remove Profanity ----Edited to Remove Profanity ----Edited to Remove Profanity ---- out of if & not worry about dropping one. Good luck


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## Georgiadawgs78 (Aug 19, 2009)

I've been told numerous times that you cant replace the lifters without a new cam as well...The only bad thing is that they have all been after the fact that I did it lol...! Finally i got the edelbrock valve covers and intake. Man does that endurashine look really good. I will post some pics tomorrow of it! We have been waiting on the intake and stuff so we can get it rolling so i should hopefully have this thing in the jeep running this weekend.


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## Georgiadawgs78 (Aug 22, 2009)

Well i went to pick the motor up friday and found out that the MSD Distributor gear was ate up bad. Some of the teeth were missing and the rest were nicked up and ground down. But it should be in and ready to pick up Monday.


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## Georgiadawgs78 (Aug 27, 2009)

Well FWIW...I picked my motor up yesterday and set it the shop hoping to get it slapped back in there tonight. To say the least it didnt happen. Got home from school, slapped a new front tranny seal in along with the new torque converter. Rolled her in the shop and eased the motor down. Got to looking to see how it lined up with the tranny to find out that I was missing one key ingredient to a functioning motor! NO FLEX PLATE was on the back of my motor! You talking about one PEOD person! So I call him up and ask him how im suppose to get my motor in without a flex plate. He says he doesnt recall seeing it with the rest of my parts and that he tore the motor down all in one spot and worked on it. He is going to look tomorrow and see if he can find it. I told him he had no choice but to find it because i know it was there on the motor when i took it to him. After a little thought im pretty sure he probably it off when he put it on the motor stand off the engine puller outside and set it somewhere else. But either way this delayed me another day and wasted my time and my buddies along with some more gas and time going and getting the flex plate. Sorry for the long post but I had to vent a little. I will post some pictures of the motor out of the jeep and hopefully get a video up soon of it running a little.


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## Georgiadawgs78 (Apr 21, 2011)

*updating with an engine video*



boneboy96 said:


> if you ever get this back up and running...I wanna see it...sounds like it's going to smoke the tires!





Maybe this will work. I know its an old thread and what not but I figured I would post a short video of the engine and what not. Shes still running strong. Sorry for the bad quality, I recorded it with my iphone and its really too loud for it lol...


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## rayjay (Apr 22, 2011)

If you like messing with fast 'cars' you should start learning to do the work yourself. It's not rocket science. Actually it's very simple. It seems difficult but that's just because there are a lot of parts. As long as you have an organized work place and go step by step it's pretty simple.

When I had my racecar / fab shop I used to build a few engines for people plus my own engines and I built a test stand so that I could breakin the cam, set the timing, check oil pressure when hot, etc. Then  the next day I would come in and retorque the heads and relash the valves and after another few test runs the motor would be ready to bolt in and drive away.  None of this lashing the valves in the car throwing oil everywhere.


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