[Troy]

Hello fellas,i am back again.I am trying to find out what type of ring i should use.This is for my 400sbc,with hypereutectic pistons,any particular ring i should use?I was looking in summit,jegs,paw,and have found rings sized at 4.155,my bore is 4.165,is this the size ring i need or what?Thank you.

[DoubleVision]

I`d use moly rings and have it honed to match them, as for size, you need a set of 40 over rings, 4.125 + 0.040 = 4.165

[BOBCRMAN@aol.com]

yes, use the moly ring, be very careful and file fit the correct end gap on the top ring, hypereutectic pistons require different ring gaps than regular cast pistons.

[engineguy]

Troy,
Definitely use moly rings and make sure that your machine shop prepares the bores properly for these rings, like 320 grit hone. For hyper pistons, I would recommend ductile iron or steel top rings, instead of grey iron. Perfect Circle, Federal-Mogul, Childs & Albert, JE, etc. have these premium rings available. They will hold up better with the higher heat that is retained in the hyper piston crown. As BobC noted, make sure that you follow the piston manufacturer's gap recommendations to the letter.