Compression numbers in.

[Husky]

I did the compression check on my motor after cam timing it correctly(I think?) today. Here's what I came up with:

2____4____6
<-Front of Motor
1____3____5

1: 143 PSi.
2: 135 PSi.
3: 142 PSi.
4: 111 PSi.
5: 150 PSi.
6: 150 PSi.

Would a head with a toasted valve acount for the number 4 cylinder pressure being so far away from the others? Or would it have little or no compression? Would I be able to push 150 PSi through the cylinders if the Cam Timing was off?

[Dave]

whelp, I'd be thinking what you've got labeled as #4 as having a bad head gasket (the side towards the firewall is the bank with 1, 3, and 5 by the way)

a bad valve CAN cause this problem, but the only way to check it now is with a "leakdown test"

--Dave.

[Husky]

Leakdown test?

Also, Yeah, a headgasket is what I'm scared shitless of. I'd HATE to have to do that, I've just gotten done with the sixth one in my Eclipse(Warped head. Really Really Really warped head)

[HayesPerformance]

Husky, Was the engine warm?????

Hey Husky,

We have been in the automotive business over 25 yrs. Was the Engine WARM? If not, even with aluminum heads warm lety the engine run from a cold start for a minute or two THEN check the compression. Or you WILL get at times a little lower piston. Also make sure that you turn the engine over a few times not just one single small crank and always check the compression Several times on each piston. Some times a small piece of dirt in the tester will give a different reading. After all that if one is still low THEN with a oil can shoot a few shots of oil in the cylinder. Now Check the compression again. WHAT HAPPENS??? Does the compression go UP? Then you got bad rings. Does it STAY THE SAME?? Then you have
1. a bad valve
2. a bad valve seat
3. a valve spring thats weaker then the rest

ANY QUESTIONS HUSKY, JUST E-MAIL US

David Hayes @
HAYES PERFORMANCE PLUS
hayesuniversal@shaw.ca

[Husky]

Thanks hayes. I tested each cylinder twice, the lower one three times. I averaged the readings together from the seperate tests for each cylinder. That's how I got my numbers. Also, for the test, I did it with a warm(not hot, didn't want to damage the heads) motor. I cranked 12 times on each test(Listened for the pop from the cylinder being tested).

I'll try the test you're talking about tomorrow or tonight. I'm currently working on my intake gaskets right now, which is a nice lead-in to my next question:

Does the Fel-Pro intake gasket set require RTV or sealant between the upper and lower manifolds, or should I just use the dry gasket?

[HayesPerformance]

Gaskets

Hi Husky,

The factory GM engine assembly manual says to leave it dry. Something that GM stresses and we practice is make sure that the surfaces are free from any oil or grease. After carefully cleaning it perfectly we wipe it clean with a lint free towel with paint thinner on it or a NON-OIL based solvent. IF there is a scratch or nick on any of the mating surfaces, then with your finger use a very small amount of high heat (like ULTRA BLACK) RTV and spread it or dab it where the scratch is and then wipe off all of it except the tiny amount what filled the crack or nick. Start all bolt FINGER TIGHT. Tighten the LOWER INTAKE to 25 N.m or 18 ft. lbs. Tighten the UPPER INTAKE PLENUM to the same torque. SPLIT THE TIGHTNING INTO STAGES. Starting by torquing all the bolts to 9ft. lbs. for instance. Do it GRADUALLY!! Start at the middle bolts and work in a circular pattern. DO NOT TIGHTEN ONE SIDE OR ONE END FULLY!!!! IF you have the right metric thread chaser / cleaner, go over all the bolts and bolt holes to make sure there perfectly clean and blow them out with air. One very important thing in any engine work is that your work is CLEAN free from ALL oil and grease.

Regards,
David Hayes

[Husky]

Got it mostly done tonight. They cancelled school tomorrow(snow day baby), so I'll be relazing and turning a wrench all day. I've still got to figure out what to do about the plenum though. You know the little thingie that plugs into the manifold on the passenger side, it's got the vacuum lines for the tranny and fuel pressure regulator on it... Well, I broke one bolt off in the manifold and toasted the threads on the other one on. Not sure how I managed to do that, but I did. I seem to have a thing for ruining bolts/nuts on these cars. I'll probably buy a Helicoil or something tomorrow, that or JBweld it in place.

[Husky]

Oh. Hayes, Yeah, I didn't wait for a reply. I used a thin spray of copper gasket maker on each side of the gasket to keep it in place while I installed. I also did chase the threads and I blew them out with canned air.

[HayesPerformance]

Vacuum Port

Hey Husky,

Put RTV on the large O-ring that is on that vacuum port to help seal it and hold it in place. You can just drill two small holes and use some course bolts or screws that will fit. The two bolts just hold that vauum port in place.

[Husky]

RTV'd it.

So, everythign was put back together today, and i was done. I sat down after washing up, and somethign was in my pocket! I Pulled it out...

LIM bolt. Fuck.

[your_I.D.]

lol that sucks.