help identifying 74 125sd pistons

[BrianTaylor]

I need some help identifying two pistons i had for a 74 125 sd...They have been sitting around for years and I thought they were both the same but now i discover there different . Piston " a " on dome is marked 54.93 Aust. sp0,07 c1  15mm wrist pin , 54.73mm over the wrist pin holes and skirt length is 60.29 mm overall lenght inside is cast 055055 then side ways 1

piston "B" is marked .020 on dome 15mm wristpin 54.2 mm over the pin holes and skirt overal lenght is 68.5mm  inside on the dome is casted ps 125

Which one of these creatures is the Penton piston....I think piston "b" is  but a .020 oversize .thks
Brian T.

Brian Taylor

[Mark Annan]

Piston A is most likely a genuine Sachs piston.  I'd have to check the overall length against another piston to be sure.  If it is a Sachs piston it is a second oversize.  54mm = stock, 54.5 = first over, 55mm = second over, 55.5 = third over.  Is it a single ring or double ring?

Piston B sounds like a Wiseco piston.  It is a "20" over (first oversize) replacement piston for a Penton/Sachs engine.

 

[BrianTaylor]

Mark they are both  double ring... I am surprised of the difference in the lenght of the skirt...Brian Taylor

Brian Taylor