Turbo KA-128psi comp before, 155 now but...

[klattr1]

well i blew my headgasket a few weeks ago getting up to 140 mph real quick(non detonation blown heagasket). Previous info before it happened: 128 psi across all 4 cylinders, 390 rwhp on sc61 turbo at 24 psi. It only made sense that my power loss was from my compression loss.I ordered ARP head studs and Cometic metal headgasket to keep the head from lifting(stock headbolts and gasket previously). I assembled everything(cams, int. man., etc) and started up the car but I immediately noticed that coolant was leaking from the head. I knew immediately that the head was warped. So I compression checked the motor and got 155 across all 4 cylinders.My reasoning comes to think that maybe the machine shop installed the JWT cams wrong(off a tooth or something) cuz my 128 psi setup was so consistent. If it was a blown headgasket that caused the low compression, it would have prolly been not as consistent.So at least I did something right and fixed the compression problem but my head is still leaking. So now I have to remove everything and bring it to the machine shop for inspection of cracks and prolly resurface. I'm looking into to see if I can reuse the metal headgasket even though i crushed it all ready by torquing down the head. We'll see. If yall get any ideas about this compression crap let me know.So now expect to see like 60 to 65 more rwhp at the same boost levels as before.I dont know maybe 440-460 rwhp at 24 psi is my hopes if all things go right. Things never work out like I plan for them but I learn as I go and make things better!

[WDRacing]

So your leaking water from the head area, but aren't burning water or losing compression? I suppose if you have a damaged head it would leak from the water jacket and not make it to the cylinder, although I've never seen it. Very strange...I would love to take apart your motor with you and check things out.

If your cams were off a tooth or somthing sever enough to cause that compression loss I would think it would idle like a**. I made that mistake on my RB and the idle was awful. But having consistent compression loss across the board only leaves a few options, warped head being one of them. I just don't get the leaking water part with no comp loss or burning. Unless its coming from another area, intake maybe.

Brian

[klattr1]

well, the leaking water came from both sides it seemed like. It started off leaking some right underneath #1 cylinder area of the intake manifold. Then I tightened down all the intake manifolds bolts to see if it would fix it and then filled the rest of the coolant in. Well, as soon as I started it up, it did run funny but I thought that was because of the coolant getting in #1 cylinder(I found coolant on #1 spark plug before compression test). So it appears thats theres no damage as of now. The cylinders are making good compression(what they are supposed to be finally!) but now I have a leaking issue. This couldnt be something thats not obvious could it? I assume its a warped head since I overheated and blew the headgasket previously but I'm not sure until I take it to the machine shop. After I pull it off tomorrow, I'm gonna inspect every inch of the surface of the block and head and make sure the machine shop checks it for cracks and warpage!Thanks WD

[C-Kwik]

Get a true straightedge. Put it against the block and head decks both straight across the center and sides and then diagonally at opposite corners. The flat surfaces should be against the straight edge. If not, measure the variance and compare it to the FSM. A stock headgasket may work better if the head has slight warpage and is within factory specs. Metal headgaskets tend to require a flatter mating surface on both sides.

Most metal headgaskets are reusable, but check with Cometic.

[sxseguy]

Does the Cometic gasket come plain like this one, or does it have oil and coolant passage seals on them like this one? Here's some additional info on making a copper gasket work correctly.

If it's the plain one, I'm sure you remembered to use some kind of liquid gasket to seal the passages, but that's never a fool-proof endeavor. Check the head for straightness once you have it off, but it could just be that one of those beads of sealant got smeared and somehow didn't seal right. Difficulty sealing the oil and water passages is while I'll probably never bother with copper.

Good luck.

[klattr1]

well, i found out the Cometic headgasket can be reused. Guy at Cometic said that the gasket would spring right back as soon as I loosened head.I will have the head removed today and at the machine shop.I'll find out soon whats the deal.

[Projex240]

any news yet?