CP Pistons from MAM: 8:1 or 8.5:1

[yellerandahalf]

Simple question: are the pistons that MAM was selling about a year ago 8:1 CR or 8.5:1 CR? Thanks!
-Matt

 

[tekkie]

Simple question: are the pistons that MAM was selling about a year ago 8:1 CR or 8.5:1 CR? Thanks!
-Matt

they sold both so it could be either if you look at them it tells you

 

[Captain KRM P5]

he also sold 8.3:1 as pdhaudio has in his engine

 

[yellerandahalf]

Ok thanks. I'm assuming they're stamped on the underside of the piston? Are they coded or obvious?
-Mateo

 

[igdrasil]

Mine are not stamped, and they are 8.5:1, at least thats what I ordered.

Check the pics.

 

[Captain KRM P5]

Mine are not stamped, and they are 8.5:1, at least thats what I ordered.

Check the pics.

thats ok i ordered stock bore and ended up getting over bore. good thing i measured them before dropping them in!

 

[igdrasil]

Well, the rings are 3.268

 

[tekkie]

Mine are not stamped, and they are 8.5:1, at least thats what I ordered.

Check the pics.

8 1-2A doesnt that mean 8 1/2? I am sure if you call CP they can tell you for sure. I know mine were supposed to be 8 1/2 and they had the same thing written on them.

 

[Captain KRM P5]

my money would be on them being 8.5

 

[yellerandahalf]

they might also be 8:1, batch 2A or something like that. Better call CP I guess.
-Mateo

 

[Kooldino]

Pistons generally come with a work order#. CP can pull that work order # to see what the specs are. Also, pistons generally come with a spec sheet.

If all else fails, simply measure the volume of the dish.