Curious as to which best to install? 312 bored .60 Mummert pop up forged pistons and Forged rods/ mild cam /113 heads/B intake...Plan is weekend cruiser some road trips cast or molly?

Thanks,
Gary

Whats john suggest ?


  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

I would use anything but cast.

Molly period. They cost a little more but last a lot longer.


-Gary Burnette-

Molley for sure,fast breakin,more hp,easey on cylwalls.

Cast rings are typically used in a "re-ringing" type low budget overhaul. With new pistons and fresh straight cylinder wall I'd go with what John recommends for the forged pistons he sell.
-Dave

As Dave notes, cast rings are usually only used these days, for low budget hone out & re ring jobs. Moly rings of some sort are better all around.


Paul

I agree with what's been said.  At an earlier time, cast rings were said to be used in race car engine teardowns because they would seat quickly in re-ring jobs where you weren't doing an actual re-build.

I'm ancient enough that I remember using chrome rings for rebuilds!  No, they weren't shiny!  


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

In my prev life as service manager for large cat dealer we went threw cronic piston sizure on v engines(3408 3412s), the cause came to light some bean counter at cat elected to delete mollry rings from v engines,not for inline 3406s as the 3406 was putting out considerable more hp pr cu in.they had no such isues and as 06,08 12 used same pistons. so afte rchanging back to molley all went well. but to get the best out of molley the cylinder walls must be honed to a finer finish, 3208 small truck engines had 2 ring pistons top molley,if cyle finish not correct early failure was a result. we used machine shop noted for race cars to get correct finish on 3208s.  just a bit of historey on molley rings

So what is the difference in cylinder wall wear Moly vs Cast? I built my 292 from a 272 block bored to std 292 bore. I saw a set of factory OEM rings on Ebay for cheap and used them. I figure with todays better oils and being my age I won't be able to drive enough miles to wear them out. The factory replacement rings come in boxed sets for two cylinders, thought that was strange..