just got my pistons out and found that ive blown the lands on num 4.the pistons have 0.25 on the tops of them,does this mean that theres been a rebore or is it because i have b's stamped on block,think i read somewhere they had slightly dif bore sizes at factory machining??

 

Yes - the engine has had a rebore to 0.25 oversize at some time.
If they were standard,they would be marked up with "A" or "B" depending on the selective bore size from the factory.

Mick

 

hi whats a or b what they stand

 

thanks Mick!.........Anyone got any pistons for sale?!

 

hi ive got some version 5 sti they have a stamped on them i dont know what there worth they are subaru forged andy forrest said the maxium on sti with standard inturnalls is 420 bhp and thats on his website there in very good condition let me know

 

"A" Piston size 91.985 - 91.995mm
"B" Piston size 91.975 - 91.985mm

The Pistons are selected at the factory to suit the individual bore sizes (manufacturing tolerances).

Mick

 

i would bronsan5000 but it seems mine is rebored 0.25 oversize!.....just what im after though!