Quench and open chamber heads

[xring]

Do we get any quench effect (with proper clearances) using dish pistons and, say, J-heads?

Thanks.

 

[ramcharger]

Nope. Your quench is limited to the head deck that resides over the bore which is very small. The only iron heads that will give you significant quench are magnums and closed chamber W2's and you'll need flat tops or pistons that properly match the quench pad. Dishes won't cut it.

 

[C130 Chief]

Didn't KB make a "reverse deflector" dome for open heads? Or are those history.

 

[moper]

Can you? Yes. But here's what it took me: Sotck block, bored .060 over. KB .070 quench domes. 346 casting heads, stage 2 ported. Block was align honed (to set the centerline in order to square deck the block). Square deck block. Took a factory forged crank, had it indexed, stroke corrected, and turned/polished. Had LY rods resized and length matched. That was the shortblock... Pistons were set to .010 above deck. Mock up block with all 8 pistons. Install heads (no gasket) and clay each piston. Take thickness readings on clay and determine which chamber was deepest. Equalize depth of chambers and polish to get flat surface (not too perfect, but I removed the casting features). The mill heads .040 each, plus .040 intake surfaces to get perfect .040 quench in all 8 holes. This engine is my own. I can't imagine getting paid to do it for soemone else. The money is better spent elswhere. They do make them, but to do it right, you need to do more than simply trim the domes as KB says. Also, if they are pressed pin, the domes have to be cut with the rod in place.