[SEL] Hercules pistons and bores.

[Curt]

Hey guys,
I found the clearance spec sheet that someone posted several years ago 
in the archives. I just put it on my website if anyone else wants it.
http://www.oldengine.org/members/holland/images/PistonClearances/PistSpec.jpg
or  
http://www.oldengine.org/members/holland/images/PistonClearances/PistSpec.tif
Curt

Curt wrote:

> Have some questions about the smallest Herc pistons and bores.
>
> On the 1 1/2 - 2 HP Herc was the bore exactly 3.250 when new?
>
> Measuring an old piston (some wear?) the following measurements are 
> found:
> Dia. Skirt is 3.243 (.007 clearance to bore)
> Dia. Land 3 is 3.238 ( -.005, .012 clearance to bore)
> Dia. Land 2 is 3.236 ( -.007, .014 clearance)
> Dia. at Top is 3.232  ( -.011, .018 clearance)
>
> Do these clearances seem right for a bore of this size?
>
> This engine has been bored to 3.264 (or .014 oversized). I have made a 
> new piston for it and am wondering if I should simply take the old 
> piston measurments and add .014 to each measurement, or if I should 
> make some changes.
>
> A long time ago someone posted an old chart showing the correct step 
> dimensions to compensate for higher temperatures at the crown of the 
> piston. Is that information still around? Glenn, do you happen to have 
> any old Hercules information on clearances and steps for these pistons?
>
> Looking forward to your thoughts and comments.
> Curt Holland
> Gastonia, NC
>
>
>
>
>   
>
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