pinto pistons

[Heliman]

I have had to put one new piston into my 2.1 pinto.
However, now that i'm about to assemble, i've found that the new piston is slightly heavier than the existing 3 pistons (approx 1.5 oz). Does anyone have any idea what the maximum weight difference is considered to be acceptable in this engine.
Many thanks for any help and assistance

 

[Jakeymd]

I would replace all the pistons. Even a small imbalance can cause your engine to shake itself to peices.

 

[MasterAuron]

That's a HUGE difference, 2 or 3 grams is ok but that's like 40 grams in real money.

 

[Heliman]

That's great advice, thanks very much.
I suspected it's too much, but now i know i can deal with it.
Thanks again

 

[T9 man]

Greetings Heliman and Welcome to our TorqueCars Forum my Friend!
Good to have you along with us

 

[Heliman]

Thanks again for the advice. I've found myself an engine builder who confirmed that every gram of weight difference is equivalent to about 10 pounds of force at 6000 revs, hence my engine probably would have destroyed itself with such a weight difference. So I've had all the rods and pistons balanced and it'll now be better than ever!!
Thanks again Alan

 

[T9 man]

That's good news Alan, try and take some pictures through the various stages for us and once you have reached 10 posts you can post them up on site for others to share. Good luck with your project!

 

[old-git]

This may be of interest to Pinto nuts:

http://www.scribd.com/doc/85121034/...Tune-Ford-SOHC-4-Cylinders-Pinto-Cosworth-DOH