Help to ID Unusual P&C Set

[tom1394racing]

I picked these up at Hershey this weekend. 89 mm bore, high compression Mahle with an 84P13 forging #.

Anyone recognize these?

[Henry Schmidt]

2.5 short stroke Ps & Cs.
Common 70's ISMA GTU

[tom1394racing]

Thank you sir

[faapgar]

Interesting ring package with cast iron top ring,total seal 2 piece gapless 2nd ring & a Swedish Deves bottom oil ring to round it out.Nice find.Fred

[fred cook]

Henry knows his stuff, but you could check with EBS to find out the precise compression of these pistons. They are Mahle dealers. The number inside the piston should tell the tale!

[tom1394racing]

The 2.5 short stroke engine Henry refers to was supposed to be at 10.3 CR

I suppose these might make good spares for someone vintage racing one of these.

[fred cook]

Sounds about right. I used Mahle pistons very much like those in my 3.3SS engine build and they were listed as 10.1:1 compression.