86 m20b25 pistons

[downforce22]

These are in an m20 that needs a rebuild, not sure about the rings yet. I am trying to figure out whether they are euro 9.7:1 pistons or 8.8:1 regular m20b25 pistons. The PO supposedly replaced the stock one with Ross Racing pistons built to 'stock' specifications but i'm not sure if this was the US or Euro m20b25 piston size.

Any good/bad reviews of ross racing pistons?

EDIT: Got the receipt from the PO for the pistons, here is the technical data for them

[MonkeyMadness]

I have a friend at Ross, I used to get pistons from while buying/wrenching on the vance&hines teams in the late 90'/2000's
Honda Rick.
Call them give them the part/build number and they can tell you everything you need to know about the pistons. Top notch company and bullet proof pistons. (they can take a ton of abuse)
or you can check the link below..

Check build sheet spec's off ross agains spec's here..

http://members.cox.net/whodwho/BMW/Mahle_m20.html

[downforce22]

I decided to buy the car and it is a euro m20b25 and i am convinced these are euro pistons based on the (very few) pictures i could find of the differences. It has the 35 pin motronic 1.0 ecu and early cooling systems etc. Can anyone very if these are the 9.7 or 9.3 euro pistons? anyone know the casting numbers?




valve pocket depth








Oh and some of the rust that needs to be dealt with soon, but this mostly the extent of the damage




the rest of the interior looks like that door card except for the seats (cardinal sports in decent shape)


the tails are in good shape