Piston Question

[V6VegaTex]

Is there any way to tell the difference between stock non-turbo pistons and stock turbo pistons? I was told this engine had cast turbo pistons, but I'm not sure how to verify that. Also, what is the signifigance of the three notches along the radius of the raised area (outside the dished area) that are facing toward the front of the engine in each piston?

Thanks,
Dave

 

[Ttype83]

Check here for the info on the pistons http://www.gnttype.org/techarea/pictureguides/pistonguide/pistonguide.html

Jim

 

[V6VegaTex]

Doesn't help much, since those are mostly aftermarket pistons. They don't compare stock non-turbo to stock turbo-- is there a difference?

Dave

 

[Silver 6]

Inside the stock turbo pistons you should find a steel plate to support both sides of the pin holes. This is not there in a standard cast piston. I have a couple sets I pulled out of an 83 TType and an 84. I'll get back and confirm, but I believe they had the oil drains down over the pin where a normal piston has it drain down into the skirt.

 

[V6VegaTex]

The pistons are still in the block, but when I turn it over and look at the inside, I definitely see the steel plate in the wall. I checked it with a magnetized screwdriver, and it's definitely steel, not some kind of casting. They do not have some of the other features mentioned in the piston guide link above, such as the wrist pin oiling hole, and the skirt looks slightly different. The cast support ribs from the pin hole to the piston crown appear to be there. Perhaps an older design Turbo piston?

Dave