Bill:

Somewhere your arithmetic is incorrect on the cost of valves.

The price I quoted of $14.00 was from my brother in law about 2 years ago who
was superintendent of transportation for Arco operating 100 tankers and
semis.
That is what they paid for sodium filled exhaust valves for Cummings or
Detroit Diesel.

My guess would be that there are many off the shelf valves available so the
designer just finds one that fits.

Hank

 
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