[Vwdiesel] Brakes --- engine brakes -- ( The physics of it ).

[W3wjr at aol.com]

By shutting the intake off (throttle butterfly in a gasser) while going down 
hill, the engine tries to suck air into the cylinders, but it can't because 
the intake is closed, but it tries hard, causing high levels of vacuum in the 
intake.  This is what causes engine braking.  

In a diesel, there is not a throttle butterfly closing in the intake, so when 
going down a hill the engine just continues to suck air, with no restriction. 
 Yes, there is engine braking caused by reciprocating mass, but nothing like 
if you had a way to close the intake causing the engine to try to create 
vacuum in the intake.  

In a message dated 1/6/2004 8:47:49 PM Eastern Standard Time, 
r.c.brown at ieee.org writes:
I initially thought you could rig up a switch to shut off the fuel cut-off 
solenoid on the pump, but I guess that wouldn't be a good idea since I assume 
the pump is lubricated/cooled by the fuel and it would run dry pretty fast with 
the input feed cut
off.

-- 
    Roger
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