On Thu, 23 Aug 2007 22:36:31 -0500, "Del Cecchi"
wrote:


wrote in message
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Now, as temperature of the gasses within the combustion chamber and
thus the pressure, is higher then ambient temperature and pressure at
the bottom of the power stroke the flow should be from the high
pressure area to a lower pressure area. In which case the engine would
not receive any air for the next stroke.

So, where does the two stroke diesel engine get the air necessary to
support combustion of the next injection of diesel fuel if not through
the use of a mechanical air pump, usually referred to as a "Blower" in
D.D. parlance

Presumably it would get them by using the crankcase as a compressor like
a gas 2stroke does.

Whether it is possible to get the necessary compression for ignition,
especially while at cranking speed, while dealing with transfer ports
etc is left as an exercise for the student.

del

Nope you are really talking about two different devices. The gas/oil
mix fueled 2-stroke provides lubrication and fuel for the engine.
Whether the oil is injected into the air/fuel stream or pre-mixed
makes no difference. Since chain saws, yamahas and model aircraft
engines, including model diesel engines run this way proves that it
will work.

But, we were discussing specifically Detroit Diesel 2-styroke diesel
engines that do not premix the oil and fuel. Quite the opposite, they
are vary carefully separated. Thus, a blower scavenged 2-stroke
diesel will not run without it's blower.





Bruce in Bangkok
(brucepaigeATgmailDOTcom)