Well a 5 inch bore 360 cubic inch four cylinder AC engine is no small
 exhaust valve. I think Cummins makes a V8 around 500 or 600 cubic inches.
 So that would be about 75 to 100 cubic inches per cylinder. In the same
 ball park with air cooled aircraft engines IMHO.

 What diesel displacement did you have in mind Bill?
 I'll measure an O-470 exhaust valve in a day or two. I have plenty
 lying around the hangar as paper weights.

 Paul Lamar

Years ago -- when I was a kid on the farm, we used exhaust valves from
Cummins as a hitch pin between a tractor and the wagons/trailers that we
hauled around.  They were about 12" long, with a stem diameter of about 5/8
to 3/4".  The thing is I don't know what size engine they came from -- just
that my uncle that worked for Cummins gave them to us as scrap, and stated
that they were sodium filled.  We never cut them apart to check, but that is
the only basis for my earlier statement.

Bill Schertz
KIS Cruiser #4045

I looked in Taylor page 414 and this is what I found.
1983 -1984

Cat turbo  six 4.75 bore 638 cubic inches 250 HP.
Cummins six turbo 4.92 bore 611 cubic inch 270 HP.
Cummins six twin turbo 5.5 bore 855 ci 470 HP.
GM 2 cycle V8 super and turbo 4.85 bore 736 ci 445 HP.
Mack six turbo  4.9 bore 672 ci  316 HP.
  
There are several more right around these bore numbers. 

Paul Lamar
 
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