On Wed, 29 Jun 2011 17:17:29 -0500, Jon Elson
wrote:

On 06/21/2011 12:37 PM, Pete C. wrote:



I would guess that with the valve cover off, the engine is breathing
through the "breather" hose on the valve cover?
Normally the breather would be applying vacuum to the valve area&
crankcase and only "breathing" the limited amount of blowby from past the
rings... but with the valve cover off it's "breathing" fresh air?

That sounds plausible. Also wondering why he isn't using a fuel shutoff
to shutdown like every diesel I've operated uses.

Many Detroit Diesels from that period had an emergency shutdown that
moved little arms into the path of the valve spring retainers, jamming
one valve per cylinder partly open , and in so doing, killing the
compression. That may be what Iggy was referring to as something moving
in the valve cover area. Taking off the valve cover on those
engines definitely would defeat that mechanism.

Jon

I believe that the spring loaded rack system was made as a substitute
for the inlet damper which DD recommended be disconnected. However
engines used in the oil industry are still required to have inlet air
damper type shutdowns.
Cheers,

John B.