piston size

[LHall]

I just took of my cylinder head to start a rebuild and I was just wondering if the pistons have some mark to know if they are original or if the engine has been rebored.

 

[Guest]

if there isn't too much carbon on top, you may be able to see .010, .020, ect stamped into the top. no mark usually means standard pistons

 

[aeronca65t]

You'd know *my* pistons aren't original!

I re-built my engine with two "scrap" engines, and it has two pistons marked "#3"!

Truthfully, the only proper way to see if an engine has been re-bored is to measure the bores with a gauge...then compare it to the specs in your workshop manual. Be sure to measure at the top, middle and bottom of the cylinder to see if there's excess taper. You can get a good idea of true measurement even if the pistons are not removed.

If you do not have a cylinder bore gauge available, or you are not able to borrow one, you may be able to rent one from a local rental agency (the rental place by me has all kinds of stuff like this).

 

[Guest]

I think he was hoping to find out without taking the engine further apart

 

[Dave Russell]

Chuck,

I don't understand your comment. Nial specifically made this statement - "You can get a good idea of true measurement even if the pistons are not removed."
D

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Chuck Cougill:
I think he was hoping to find out without taking the engine further apart

<hr></blockquote>

 

[Gary Lloyd]

You can if you have an inside micrometer!! Anyway, there should be a stamp on the top!! I have never seen an oversize piston unstamped!! Anyway, I would think a guy would really want to know what his bore is like instead of putting back an unknown quanity!! GOOD LUCK!!!!!

 

[mowog]

I guess Gary answered the life long question size really does matter

 

[Gary Lloyd]

Yup!! We are talking piston diameter here Phil!!