Rare Piston ID help needed...

[Unobtanium-inc]

After going back and forth with Tom Butler for 3 days, he suggested I reach out to the masses of experts on the board. So I'm reaching. They are 80mm, have a 906 dome profile (or similar), but only 2 rings. They wear part number 80P25+ and underneath that is W3. The W3 is NOT stamped like the E, which is also there. Check out the pics, and if anyone can help...

[preS]

Adam are you sure it's 80 and not close to 81 mm? Andial sells the 81 mm Mahle piston and if I recall correct does it not have a ring under the pin.

Richard

[Unobtanium-inc]

I'll have to mic it but they are in 80mm cylinders. Unless the cylinders have been modified they are 80.

By the way, Matt here. I handle the 911 side of things. Nice to meet you.

[BURN-BROS]

The 80.95 stamping on the top of the piston infers to it's size and cylinder type. Which in this case is for a 81mm iron bore. IIRC these were for either IMSA or SCCA as per their rules at the time. I will ask around to get more info tomorrow.

[Unobtanium-inc]

So I guess this means the cylinders had a larger bore. They are stamped 80ZD... (can't remember the exact part number, but you know what I mean) but are larger?
Thanks for all the help, keep the info coming!

[preS]

So I guess this means the cylinders had a larger bore. They are stamped 80ZD... (can't remember the exact part number, but you know what I mean) but are larger?
Thanks for all the help, keep the info coming!

Another reason I think they are the Andial supplied oversize pistons (you have to bore your old birals).

Richard

[Unobtanium-inc]

Another reason I think they are the Andial supplied oversize pistons (you have to bore your old birals).

Richard

Well why didn't you just say so? Seriously, thanks for the help.

Matt

[preS]

Well why didn't you just say so? Seriously, thanks for the help.

Matt

I didn't say so since I am traveling and I have to trust my memory

Harry Pellow taught me not to assume

Richard

[kenikh]

Harry Pellow taught me not to assume

Far too long since I heard the Maestro mentioned. RIP.

[911quest]

Aaron's correct the were an over bore piston used for some SCCA classes in the past. I have a set and EBS say's they can get rings for them I could use the spares if you want them to go away.