[94cobra69ss396]

Were they all low before or just the ones that were broken? If they were all low before I don't see how they won't be now. Are you sure you have as high of a compression ratio as you thought? What type of pistons do you have, flat top or dished? If dish what's the cc? How thick of a head gasket are you using? What the deck height on the pistons?

[enkeivette]

I've done the math before obviously, but feel free to double check.

Standard deck height which is 20 or 25 down, -5cc reliefs, 74cc heads, 61 HG, 4.03 bore...

I get about 9:1, with a 110LSA I guess I shouldn't expect much dynamic.

[BRUTAL64]

Originally Posted by enkeivette

Got my new piston pressed today. In the process of removing the old rings, and I've snapped several. Is there a trick to installing the new ones without snapping them?

Also, setting the gap at .022, did the Total Seal math and I get .022165 for a blown gas engine.

Old rings were not installed upside down.

I've been doing the ring install by finger and thumb since the 70s. I'd have to show you how it's done. I don't think I could explain in words.

[BRUTAL64]

Originally Posted by enkeivette

I've done the math before obviously, but feel free to double check.

Standard deck height which is 20 or 25 down, -5cc reliefs, 74cc heads, 61 HG, 4.03 bore...

I get about 9:1, with a 110LSA I guess I shouldn't expect much dynamic.

Just ran your numbers thru the engine program I have. I got 8.49 ratio.

I did it three times.


I used the same program on my engine.

I ran that for a 350.

For a 383 it is 9.17

[94cobra69ss396]

Originally Posted by enkeivette

I've done the math before obviously, but feel free to double check.

Standard deck height which is 20 or 25 down, -5cc reliefs, 74cc heads, 61 HG, 4.03 bore...

I get about 9:1, with a 110LSA I guess I shouldn't expect much dynamic.

What's the bore on the head gasket?

[BRUTAL64]

Originally Posted by 94cobra69ss396

What's the bore on the head gasket?

I used 4.060 bore for the head gasket.


With a 4.030 hg bore the cr is 8.50.

Again, that is for a 350.


383 with 4.060 hg bore is 9.17

[94cobra69ss396]

Originally Posted by BRUTAL64

I used 4.60 bore for the head gasket.

He has a 383 with a 3.75 stroke, correct?

[BRUTAL64]

Originally Posted by 94cobra69ss396

He has a 383 with a 3.75 stroke, correct?

Shit that is right. Ok, I'll redo it.

383 is 9.17

[enkeivette]

Knew I forgot something, 4.166 bore HG, 3.75 stroke. 6" rod if that matters.

[BRUTAL64]

Originally Posted by enkeivette

Knew I forgot something, 4.166 bore HG, 3.75 stroke. 6" rod if that matters.

I got 9.12 cr.