Can anyone ID these pistons?

[sprbxr]

I have a turbo engine that I acquired disassembled. I have 2 sets of 98mm pistons with 23mm wrist pins. I was told both sets were Mahle Motorsport pistons. There are no markings on the pistons. The dome on one set is substantially taller than the other set. I have not yet measured the dome volume on either set although I will eventually.
Anyone have a guess at what CR these pistons are?

[sprbxr]

Anybody?

[Geronimo '74]

Nope, sorry

[db_cooper]

I'm just guessing, without part numbers, who knows?

The low compression pistons should be for a turbo engine, the high dome, a normally aspirated engine.

Specs for a turbo call for about a 7.0:1 compression ratio.

Normally aspirated engine has about 9.5:1

[barryr]

I don't know for sure but something that might help a bit is the one on the left with the higher dome has very shallow valve pockets so this would be for an engine with quite a mild cam. The one on the right is the opposite. It has a lower dome but quite deep valve pockets so the cams designed for these pistons would be of a long duration with a high lift. If you can find the specs on engines that use 98 mm pistons and can also find the valve timing values for those engines you should be able to figure it out.
Barry

[euro911sc]

Try posting this in the Engine Rebuild forum. Lots of piston knowledge there. GL!

-Michael

[356RS]

Tom Butler will know. Tom is an expert on identifying heads & pistons, case's etc.

[sprbxr]

Ok. I know Tom.

[David]

The one on the left looks like it would be pretty high compression for a turbo. The right one looks closer to stock compression.