Quench area

[D@nno]

I'm in the process of building up a 2.4, and am wondering what kind of piston to head clearance I should be shooting for. I've heard the smaller the better to help with reducing detionation. The pistons I'm getting have an .008 deck clearance. I'm thinking of decking the block to bring the clearance to 0 and using the .030 gasket, which is the smallest i've seen. Will this be enough clearance? I read a magazine article about a guy who ran .024 on a sbc with stock rods! The pistons were just kissing the heads at 7000rpm.

 

[D@nno]

Oh ya 1 more question. Since i'm running a little more bore
i will unshroud the valves a little more, but what is the deal with polishing the combustion chamber? Very smooth or a little rougher to help with mixture?

 

[5150DSM]

Oh ya 1 more question. Since i'm running a little more bore
i will unshroud the valves a little more, but what is the deal with polishing the combustion chamber? Very smooth or a little rougher to help with mixture?

Unlike the ports and runners, a nice even polish, that removes as little material as possible is ideal for the combustion chambers. Rough surfaces increase the surface area of the chamber and incrementally slow flame front propogation and travel. Also, the little "nooks and crannies" in a rough finish are collection areas for carbon deposits and can eventually create hotspots. The key to polishing combustion chambers is to achieve the polish by removing the smallest amount of material and deforming the chamber as little as possible; the overall shape of the chamber determines the speed and travel angle of the flame front and altering this can have undesireable effects. Hope this was helpful.
Aloha

 

[D@nno]

Yes it definately does, thank you! I will be reshaping the combustion chamber a bit with unshouding the valves but i will also be getting the head shaved to keep it close to the same cc. Any advice on the quench area size?