engine and drivetrain pistons

[742002]

I am currently rebuilding an engine for my 02. the motor is out of a 75 so it had an e12 head. will the pistons in this motor work with my 121ti head that i am going to have rebuilt, or will i have to get new pistons?

[Guest Anonymous]

the 121 head went with flat topped pistons, the E12 head goes with the "piano" popup pistons. Back in the old days, some people would reshap the popups to use them with a 121 head and get higher compression. it took lots of careful work to make this happen. You'd be better off with an E12 head or with flat top pistons.

[Mike Self]

I'm getting ready to do a rebuild on my 73, and have two sets of new 9.5 Mahle pistons: std and .5mm oversize. If you're not in too much hurry, whichever set I don't use will be for sale. Won't know what I'll need 'till I get the engine apart sometime in early December.

Lemme know if interested

Cheers

mike

[jerry]

I was under the impression that the 121 and 121ti head used the "bathtub" topped pistons which I am also under the impression that these are NLA.

True?, False?

any idea of the compression ratio obtained using flat tops with the 121 heads?

the idea of reshaping 'piano tops' to work is intriguing. is this done with clay, machinists bluing, a file and patience???

[meyekel]

i just rebuilt my motor with a 121 head. the oversize pistons for this head are pretty scarce so i went with custom forged jobbies from ireland/ross. you can get the bathtubs in any ratio you want and they have nicely cut valve pockets too. well worth the money and they are lighter and stronger than the cast pistons, assuming you can find some.

mike r