how do I know I need A or B?

 

I believe on the backside of your block, on the driver's side, there is a piece of block that faces straight up that says either A or B; it tells you which piston sizes your motor uses.

 

on the driver's side behind the water pump. Also if your engine is already out or it has been decked (which would remove the stamp) then the old pistons if they are stock will have a slight stamp in the very center of the piston head that will say A or B.
the Pirate

you'll have to clean some carbon though


Modified by PirateMcFred at 7:13 AM 3/18/2004


Modified by PirateMcFred at 7:14 AM 3/18/2004

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PirateMcFred &raquo;</TD></TR><TR><TD CLASS="quote"> on the driver's side behind the water pump. Also if your engine is already out or it has been decked (which would remove the stamp) then the old pistons if they are stock will have a slight stamp in the very center of the piston head that will say A or B.
the Pirate

you'll have to clean some carbon though


Modified by PirateMcFred at 7:13 AM 3/18/2004


Modified by PirateMcFred at 7:14 AM 3/18/2004</TD></TR></TABLE>
damn you killed that Q
good ****

 

i just bought a set for my motor but damn i didi not know and they did not ask me what type a or b. they should arrive tomorrow but what is the difference and what can happen mine is a 2001 block with a 94 head

 

I can't remember which, but one is slightly larger than the other, but smaller yet than the OS or oversized piston that is .25mm larger.

the Pirate

 

A Piston = 86.990 - 87.003
B Piston = 86.980 - 86.993

A cylinder = 87.010 - 87.020
B cylinder = 87.000 - 87.010

given a piston-to-cylinder clearance of .007 - .030mm if you were to put an A piston in a B cylinder bore there's a good chance you'll wreck your block through interference or too tight clearances.

 

Thanks satan