Most likely a result of the continued burning of the fuel while the piston
is at a lower position in the cylinder bore and the still burning
combustion going out into the manifold.
Paul A
FROM: "David Riker", INTERNET:davidr at sunset.net
TO: "Larry Macy", INTERNET:macy@bblmail.psycha.upenn.edu
"Paul A. Asgeirsson", PAsgeirsson
CC: "spridgets", INTERNET:spridgets@autox.team.net
DATE: 7/25/00 11:38 PM
Re: Re: Timing Vs Over Heating--Longish!
When California was trying to reduce NOx emissions back in the 70's, the
approved kit contained a vacuum cap to disable the distributor vacuum
advance, idle timing of about 6 degrees ATDC, and a warning decal for the
speedometer that read something like "Prolonged speeds above 50 MPH may
result in engine overheating and severe engine damage". Also, the factory
setting for a 78/79 1500 Midget engine is 2 degrees ATDC, and a common
complaint is engine overheating. In these two examples, is the additional
heat a result of more complete combustion although occurring at a time in
the cycle when the heat is wasted? Or is it the unburned fuel burning in
the exhaust system? Not that it matters, just curious of course.
David Riker
|