[enkeivette]

Crankcase is blowing air at me like crazy, oil is still clean. Consensus seems to be that it's a f'd ring or a hole/ crank in my piston. Pistons are forged so I'm optimistic and hoping that it's a ring.

Also, this engine only made 135psi in each cylinder when it was running good. And it's always made less power than it should for what it is, someone hypothesized that my rings were installed upside down. It would def explain things. Either way, pistons are coming out.

Also, this would explain the excessive crankcase pressure that I've always had a problem with. Anyone else remember the oil squirting out on dyno day? Maybe it wasn't the intake leak.

Just pray for me that the pistons are still usable and the cylinder is still smooth.

[big2bird]

You have a hole, or a broken land.

[big_G]

And you must find out why it happened so as to not have a repeat occurrence. Detonation is #1 on the list of causes. Too lean next. When you pull the plugs you will know.

[BRUTAL64]

Yea, I blew 4 piston ring lands out with detnotion. Figure worst case here.

[joedls]

Do you have a PCV valve on it or breathers? Also, I'd do a leakdown test before I pulled it apart.

[94cobra69ss396]

Originally Posted by enkeivette

Crankcase is blowing air at me like crazy, oil is still clean. Consensus seems to be that it's a f'd ring or a hole/ crank in my piston. Pistons are forged so I'm optimistic and hoping that it's a ring.

Also, this engine only made 135psi in each cylinder when it was running good. And it's always made less power than it should for what it is, someone hypothesized that my rings were installed upside down. It would def explain things. Either way, pistons are coming out.

Also, this would explain the excessive crankcase pressure that I've always had a problem with. Anyone else remember the oil squirting out on dyno day? Maybe it wasn't the intake leak.

Just pray for me that the pistons are still usable and the cylinder is still smooth.

How big is the cam in the Vette and what's the compression? The Cobra with a 110 lobe seperation and 9:1 has 155psi cranking pressure. Also, how much boost are you running? Did you ever here it detonate? Forged pistons can take quite a bit of abuse. I've had the Cobra detonate quite a bit with the forged pistons and haven't had a problem with them in the 2 years they've been in there. I also have around 30,000-40,000 hard miles on it.

[SeanPlunk]

Originally Posted by 94cobra69ss396

How big is the cam in the Vette and what's the compression? The Cobra with a 110 lobe seperation and 9:1 has 155psi cranking pressure. Also, how much boost are you running? Did you ever here it detonate? Forged pistons can take quite a bit of abuse. I've had the Cobra detonate quite a bit with the forged pistons and haven't had a problem with them in the 2 years they've been in there. I also have around 30,000-40,000 hard miles on it.

As I recall his compression is 9.5:1? I think his cam has a 111lsa but I can't remember for sure. I think he's running 15lbs.

[94cobra69ss396]

Originally Posted by SeanPlunk

As I recall his compression is 9.5:1? I think his cam has a 111lsa but I can't remember for sure. I think he's running 15lbs.

His crancking pressure should be higher than the Cobra's 155psi with 9.5 and a 111 lsa. To give another comparison, the Chevelle with 12.25:1 and a 110 lsa has 210-215psi.

[BRUTAL64]

Originally Posted by joedls

Do you have a PCV valve on it or breathers? Also, I'd do a leakdown test before I pulled it apart.

Hey, Joe. Where ya been?

[joedls]

Originally Posted by BRUTAL64

Hey, Joe. Where ya been?

I had a death in the family, then I had the flu for about a week. I've had my head down trying to catch up.