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gecoe
07-19-2005, 07:39 PM
Hi All,

I had some resurfacing work done on the head of my 50 Champion last week and put everything together Friday. While the head was off I noticed that the block has "05" stamped near the left edge between each of the pistons. I'm sure this must tell me something if I knew enough to read it but I can only make guesses. Can anyone set me straight?

Thanks,

Gerry

curt
07-19-2005, 08:06 PM
I had a block that was stamped.06, it was bored .06 over in the cylinders.

gecoe
07-19-2005, 11:42 PM
Thanks!

I kinda suspected that but also wondered if it might have to do with the block being resurfaced.

Gerry

Dick Steinkamp
07-19-2005, 11:55 PM
.060 is a standard oversize. .050 is not. In fact, I have never seen .050 oversize pistons. I doubt if the block has been bored .050.

I heard somewhere that Studebaker fitted individual pistons to the bores much the same as Porsche does. The stamp by each bore may indicate the over/under size for that individual cylinder. In that case, the number is probably more like .005.

-Dick-

Dwain G.
07-20-2005, 12:24 AM
This is mentioned in most all Studebaker shop manuals. It denotes the final finished size of each cylinder bore. '05' means that the actual cylinder size is 3.0005", or 5/10,000 of an inch, which is half of .001". The engine assemblers would know to select a piston compatible to that size in order to achieve the proper fit, which was measured with a special feeler gauge and a spring scale.
And after a few thousand miles of operation, those numbers don't mean a thing anymore! <G>

Dwain G.

gecoe
07-20-2005, 12:47 AM
Yup, page 124 of my shop manual, plain as day had I only looked. I'm a bit embarrassed over not looking there first [V] but definately appreciate the guidance Dwain.

Thanks!

Gerry