What Engine Is This Piston From?

[Dolly-Nut]

Sprint? TR7? Note the step and slightly smaller valve cut-outs than normal Sprint pistons.

I found them sorting through my piston collection pearler.

[dursley92]

That sure looks like a TR7 piston, see this picture of a couple of different TR7 types.




I also found this picture of a TR7 piston modified with extra valve pockets to use in a Sprint but I guess the compression ratio would be pretty poor.