Tim81

Maybe one of the engine builders can help me out here. I have a set of Cast (not hyper) Silv-O-Lite 1436 pistons. I've read that the top ring gap must be increased on the hyper type pistons, is this true for the plain cast aluminum pistons too? I know its a strange question. Tim

427Hotrod

No....just use the std .004" or so per inch of bore and you'll be fine. Current thinking is to run a few .000's more on the second ring than the top one.

JIM

jackson

It has nothing to do with material ... it has everything to do with how thick the top land is (how far the top ring is located toward crown of piston). Both KB and silvolite are made by same company (UEM) and the KB hypers usually have a relatively short top land. The closer the ring is to top, the hotter it gets ... and requires increased gap.

additionally, 1436 has very short 1.540" compression distance ... unless the block gets severely decked it will likely have a poor (too-wide) quench and maybe low compression. CD about 1.560" is nominal.

I do Not like any cast or hyper piston from UEM; don't like several design attributes & don't like quality of machining. I guess UEM ok for the cheapest of non performance replacement rebuild? Suggest a similar cheap hyper piston from sealed power such as H631CP or H669CP or H345NCP; they're hyper but do Not require increased gap.

You local auto machine shop can help you choose and may work with you on parts cost.