[Damian]

I doubt it. You looking almost in the realm of the difference in plug gaps.

[enkeivette]

I doubt your plugs are that close, but crank it to TDC stick your pinky in there and see if there's reason for concern.

[enkeivette]

Word on the street is that stock pistons come out of the block a bit. So you might be able to go bigger than .054. And obviously drop more than .25 points.

[94cobra69ss396]

Originally Posted by Vettezuki

If going to a thicker gasket to drop CR, the only way to maintain quench (assuming I even have vaguely correct quench as it is), would be to change pistons right? If not, you need to elaborate.

Guys, here's a picture of the quench area that I outlined and have an arrow pointing to. It is where the flat area of the piston meets with the flat area of the head. It can only be changed by using a thicker/thinner HG or by resurfacing the block so that the piston is not as far down in the hole.



I'm just starting to assemble the 355 for our Camaro and need to order bearings and head gaskets so I measured to see how far down the piston is. On our new block the piston is .029 down so I'm going to go with the thinnest gasket I can find to try and get the quench as close to .050 as possible. We are using a forged piston with a long skirt and a tight piston to wall clearance so we could go tighter than .050.

[BRUTAL64]

Originally Posted by enkeivette

I'll bet GM thinks about it less than we do.

Bet they don't. Why do you think they came up with a FAST BURN chamber?


Well, actually, Smoky designed that chamber in the Sixites.

[BRUTAL64]

Originally Posted by 94cobra69ss396

Guys, here's a picture of the quench area that I outlined and have an arrow pointing to. It is where the flat area of the piston meets with the flat area of the head. It can only be changed by using a thicker/thinner HG or by resurfacing the block so that the piston is not as far down in the hole.



I'm just starting to assemble the 355 for our Camaro and need to order bearings and head gaskets so I measured to see how far down the piston is. On our new block the piston is .029 down so I'm going to go with the thinnest gasket I can find to try and get the quench as close to .050 as possible. We are using a forged piston with a long skirt and a tight piston to wall clearance so we could go tighter than .050.

Good illustration. I use a .032 copper head gasket.

[94cobra69ss396]

Originally Posted by BRUTAL64

Good illustration. I use a .032 copper head gasket.

I found a .021 one but it says the block must be O-ringed. I'm still looking.

[enkeivette]

Ben, you can also retard the cam 4 degrees, which would bleed off compression and lower your dynamic compression ratio. Then just rock it back when it's time to smog if you would even need to.

And for fun you could even rock it forward 8 degrees (4 degrees advanced) for the track, fill up with Torco and see if you run faster. Cornfed did this if I remember correctly.

[enkeivette]

Originally Posted by 94cobra69ss396

Black arrows show how you can increase HG bore, decreasing CR, without changing quench.