[SEL] The McVickerish Engine

[Larry Evans]

Elden:

This reminds me of an experiment I ran a while back with the 50 hp. 
Fairbanks Morse spark ignited engine at the Mount Wilson Observatory.  What 
I did was run the engine up to its regulated speed of 290 rpm. and then 
killed the ignition and fuel to shut it down.  It took 2 minutes and 45 
seconds to come to a complete stop.  I then did the exact same thing but 
also opened the compression releases at shut down.  It took just 2 minutes 
to come to a stop which indicates to me that governing against compression 
probably is a little more efficient than not.

Larry

At 06:54 AM 3/23/2010, you wrote:
>Jim:
>
>Unlike Diesel exhaust brakes, the McVicker engine is not working as a true 
>compressor when it is in "miss" mode.  The mixture is compressed and 
>expanded, acting more like a spring - taking energy on compression and 
>giving (most of) it back on expansion.
>
>Take care - Elden
>http://www.oldengine.org/members/durand

Larry Evans
MailTo:LFEVANS at pacbell.net
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