I bought a set of type s pistons for my engine rebuild. But when I recieved it, my cousin said they are oversized. I got it from ebay and the guy said they are standard bore, and drops right in. I tried to fit them in and they dont fit. How do you tell if the type s pistons are oversized or standard?? Are there any numbers or so that I can look to tell?? thanks

 

i am not sure, i've looked into getting some type s pistons but i need to finnish rebuilding my head first...try a search there is a lot of onfo on type s pistons

 

The oversized Type-S piston is measured at 87.25mm. All you can do is Mic it and see.

 

are they used or new? If they're new they'll have an ink stamp on top of them that say .25 OS on them. Real light. Also, OS pistons don't have A or B designations, so if any of them have "B" in that circle in the middle of the piston head, they're not OS.

 

They're new. i'm so mad, I wanted standard so I ordered standard. but I got oversized instead. On the top, it says 25. that's all i can see, and there's no A or B. What's the good side of having oversized type s pistons??

I tried searching too but couldn't find much..

 

Its just easier, in the case you have A and B Type piston. The machine shop can just bore it over so it is exactly 87.25.

Well that not the real reason it just sounded good. Its for incase you go over the service limit with the piston to wall clearance. You can go .25 over with out resleeving.

 

well, you're slightly increasing your displacement, and you're increasing your CR as well.

 

I was told since it's oversized, i should be gettin a lil more power from it. Is that right???

 

maybe .5 to 1 hp.