[SEL] Fuel Intake Compensating Valve Theory/Question

[Curt]

John,
I too have a question about the compensating air valve on the Fairbanks 
engines. We have a stand alone Fairbanks engine and air compressor used 
to build air pressure to start the big Fairbanks at our show grounds.
We have cranked on that that little engine until there are several 
bloody hands. Then one of us will finally recall that the throttle plate 
has to be manually held closed or near closed. It will start instantly 
then. At rest the governor spring will hold the throttle plate wide 
open, and I cannot imagine FM intended as part of the starting procedure 
to hold the throttle closed manually.
Can you venture a guess as to what might be wrong so we might correct 
the problem?
Curt Holland
Gastonia, NC

John Hammink wrote:

>The purpose of the compensating air valve is to insure the correct
>percentage of fuel in the mixture, regardless of whether the engine
>is running fast or slow, under full load or idle. The suction of fuel
>varies with the speed of the piston and the opening in the air intake
>pipe. The compensating valve compensates for such conditions.
>I think he found it experimentally after some different designs and
>constructions.
>
>John Hammink
>Anna Paulowna, Netherlands.
>jg.hammink at quicknet.nl
>www.oldengine.org/members/hammink/web
>
>  
>