kb368. Well after hours of searching these were the only pistons i could find for a 429. the cast pistons that i originally had were for a 460 so they sat down a good ways. the only other pistons i could find were from companies that custom made pistons (these were the only forged 429 pistons i couuld find) and were far to expensive for me. I will talk to the builder about all the stuff you listed above and hopefully he understands and doesnt think i am questioning his expertise. thanks for all of the tips and if you have anymore feel free to share.
ryan brindle
Per KB Website:KB368 0.060" overbore / marine application / normally aspirated: Set piston-to-bore clearance at .0035"-0.0050" & top ring end gap to 0.0035" (second ring end gap is typical spec for a piston of this size).
Many people scoff at such a wide top ring end gap and set it much tighter, which (with these pistons) causes the ring ends to butt against each other and push against the bore and destroy the engine. This is one of the reasons that hypers get a bad name but the KB's are actually pretty nice. Follow the specs as outlined above in this post and you'll be okay in this area.
Also, make sure you run the engine's air/fuel mixture settings a little on the rich side. Hypers don't take well to detonation and are easily destroyed by it. Better to run slightly rich and risk fouling a plug(s) than have a piston disintegrate while the engine is running. Again, follow the specs and do net jet too lean and you'll be okay.
The deck hieght of your block is supposed to be no less than 10.300", and the stack hight of your rotating assembly is supposed to be 10.300", so in this particular case your piston's deck height
should be fine, but be sure to check that your pistons are not too far out of the hole at TDC (not more than 0.005" in your particular case, assuming Fel-Pro 1018 head gasket) because all these dimensions are theoretical and each rod may have a longer center-to-center, etc.
LO
p.s.: The forged TRW 429 pistons, #2366 (TRW-L2366F30, TRW-L2366F40) used to be available in a 0.060 overbore, but with a different part number, TRW-L2368F60. Indeed, I don't believe they are available any longer. On the other hand, there are more 460 forged pistons than ever...so another option to your dilemma could have been simply locating a dime-a-dozen 460 crank and then purchasing 460 pistons, as the rest of your engine is the same as a 460 (429's only has different crank and pistons than a 460, the rest is the same). Basically 31 more cubes for the price of the crankshaft.
