what does .030 mean

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Apr 22, 2010 | 08:56 AM

#16

bombebomb

Registered User

Joined: May 2006

Posts: 1,855

From: Ohio

Quote:

Originally Posted by dangalla

the number indicates the difference from stock

and yes you should be measuring everything anyway, but if the piston says .030 on it then there is an overbore of .030

Yeah I got that much haha

Quote:

Originally Posted by shoebox

...because it is assumed that you know the engine (stock specs) that you are looking at (an LT1 isn't going to have a 3.000 bore) and the marking is the deviation from stock size.

Pistons and bearings have always been marked this way. If was too confusing for folks, I think they would have changed it by now.

Indeed, I guess I was under the assumption they do not make LT1/350 specific pistons (meaning if you had some other CI engine, with a larger stroke, smaller bore equaling the same CI). It is obviously a matter of knowledge on the builder to choose the correct size of course. I am pretty darn sure I put to much thought into this haha.

With all that being said, I understand all .030 pistons are marked as being .030 the stock size.