What I try to recommend is a piston that has a sufficient amount of flat area on the crown that it will be able to "squish" the mixture (that would normally be in between the piston crown and the underside of the cylinder head), across the chamber, creating turbulence and homogenizing the air fuel mixture in the chamber to help insure complete combustion of the mix. Building a tight squish (0.035" to 0.045" on a SBC) will also help to prevent detonation and may allow the motor to operate on a lesser grade of fuel than if you didn't have a tight squish.
If a fellow has to use a dish at all to reach the intended static compression ratio on his build, I prefer the "D" shape of the Keith Black pistons. They have a generous flat area on the crown to generate the proper squish at close to TDC. Pistons that have circular dishes generally don't have enough flat area on the piston crown to cause the mixture to "squish" across the chamber.
I would back down a little with iron heads, closer to 9.5:1. Here's a forged piston from KB that will produce a 9.6:1 SCR with 64cc heads. http://www.kb-silvolite.com/icon/icon.php?action=details&P_id=21
Notice the compression height on these pistons is 1.433", 0.008" taller than most 383 pistons that measure 1.425". This additional compression height will get the piston crown closer to the block deck at TDC and should make it easier to adjust your SCR and squish.
Choose a cam that closes the intake at ~35 degrees ABDC @0.050" tappet lift for a dynamic compression ratio of 8.49:1 that will operate on pump gas.pisto
There is a line of Sealed Power pistons w/a smaller diameter, deeper round dish that have a wider squish band that might be a better option than the traditional shallow round dish pistons- especially the ultra weak shallow dish w/45 degree chamfer around the circumference. Both are shown here.
I've not had the time to research this line of pistons fully for application and specs, but I do know the piston shown (H423NP w/10cc dish) has a 1.54" compression height. I'm hoping they also have this dish type in 1.56" CH, and for a 383 SBC stroker, too.
If anyone happens to have this info I'd appreciate a link or the info can be simply added to the wiki (link above).
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