i dont know the story behind your setup. what were you running motor wise and what numbers were you hitting?

sad to say, it sounds like a hg issue to me. :-( valve seat or something like that wouldnt be across the board. sounds like the head is warped from being lifted.

how much boost were you running? stock head bolts? and what hg?

 

2mm copper SCE head gasket, stock bolts, built head, 14-16 psi on 91 pump. I put down 457 hp on a dyno dynamics tuned by Mase.
Scott (DSDDCD) was running this gasket also and his leaked.. ( between each cylinder and the water jacket also)

 

hmmmmm...

the tune numbers sound awesome actually. i highly doubt that was the problem.

sce gasket and stock bolts might be it. the reason i say that is because those sce gaskets give false torque numbers because it requires a higher amt of torque to flatten the beveled/raised "sealing" edges.

over time, they part that was originally very tight gets loose from the lack of force exerting in all directions from the raised edges that are now flattened and heat cycled, thus requiring more torque since the crush space has now changed.


thats a lot of rambling but i bet a few of you who have used sce products will know what im talking about.

ran into the same issue with turbo inlet gaskets made by them. gaskets looked diesel and stout, but the compression of everything changed after flattening and heat cycles.

 

I re torqued the SCE twice, once after a few heat cycles and then a second time at around 6K miles... The second time it was seaping coolant out of the side of the block but the re torque took care of it. Yes I always kinda knew I was going to have to revisit the gasket...

I was planning on putting a 3mm inline pro gasket with ARP's, but Scott (DSDDCD) just put one on and he tested his number one cylinder yesterday and it pushed coolant just like me. I am unsure how much pressure he was putting into the cylinder though.

 

Okay the results are in, a factory HG definatly does not raise the level and the random misses I have are DEFINATLY attributed to the leak as the car I tested/drove was SOOOOO much smoother.

I am going to start research on a set of low comp pistons. Since my bores are prefect I will just throw them in with the stock rods and crank. I found some great details on a Porsche site for cylinder preperation which should be quite easy.

 

My bores were not perfect like yours..

 

OK, I've decided I need to pull the head ASAP and replace the head gasket. That will buy me some time to get another motor together with 9:1 pistons.

I was looking at trying to Cosworth 1.1mm gasket as it looks promising, but it only comes in 88mm bore as its smallest option (1mm over stock bore). Do you think running this gasket would be a problem?

My only other option I'm willing to go with would be an OEM gasket and to turn the boost down even more.

 

I thought you guys would have learned by now. Stock HG and call it a day. Let it make what it makes, who cares about the actual numbers except the penis swingers here on the internet.

 

Post up that link man!!

 

lol penis swingers.



x2 on anything but stock HG.



i am excited to see someone try the low copression pistons in a stock bored, stock materialed sleeve.