<VV> piston boss thickness

[djtcz at comcast.net]

snipped and bottom posted

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 -------------- Original message ----------------------


> From: Bryan Blackwell <bryan at skiblack.com>
> Subject: Re: <VV> Pistons ok?

> Thanks again for the comments.  My real concern is not the rods, it's  
> the pistons, so I took a couple more photos:
> 
> http://autoxer.skiblack.com/BlogPhotos/IMG_1112a.jpg
> http://autoxer.skiblack.com/BlogPhotos/IMG_1115a.jpg
> 
> Material was removed under the pin, I put the two extreme examples in  
> the photo.  The piston on the left has the most material, the one on  
> the right has the least out of the set.
> 
> Thanks for any guidance.  BTW, the pistons are brand new.
> 
> --Bryan
> 
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So, the thinnest piston boss shown is on the right? How thick is it?

http://autoxer.skiblack.com/BlogPhotos/IMG_1115a.jpg

I think one of the other pix showed at least one piston that had its bosses machined deeper/thinner  than the thinnest stock section.  On pistons with real thin sections We used to always leave a "witness mark" where some of the factory machining or as-forged surface was left to show that we did not go thinner than stock.

I seem to recall Speed Pro saying that section was OK at 0.200 inch or so for race small block Chevies

Dan Timberlake
Westford, Massachusetts, USA