On 2010-05-20, Wild_Bill wrote:
I assume that the V-twin design is much better for cooling, and likely
extends the reliability of pumps for air compressors.

It is better for cooling, definitely. This head is very large, and
weighs 800-900 lbs. It is like two 390 heads in a twin configuration.

Siamese cylinder designs still have good reliability if designed properly,
but my guess is that separate cylinders and heads can run cooler.

They have much greater cooling area and suffer less from vibration.

I just picked up a V-twin model yesterday, but the pump's a lot smaller than
the Quincy 5120-A in your pics.. probably in the 5-7.5 HP range (depending
upon model).
It is a complete air compressor, 60 gal, vertical model.


340 pump is 5-10 HP (depending on RPM and top pressure)
325 pump is 3-5 HP

If it is a Quincy V-twin head in this size, it is likely to be a QT
head.

I had a twin headed 5 HP CUrtis compressor.

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