mgs
[Top] [All Lists]

Re: Fuel/overheating

To: MGBCHRIS%aol.com@aphub.aerojetpd.com
Subject: Re: Fuel/overheating
From: KILE_PAUL@aphub.aerojetpd.com (Paul D Kile)
Date: 14 Jun 96 06:49:48 PDT
Chris, I agree with your comments on the avgas reducing pinging and 
detonation, but not on the other two issues.

As mentioned earlier by another respondent, Tetraethyl Lead was added 
to gasoline originally to increase its octane rating.  There is a 
frightening story about the fellow that introduced TEL in the 1920s.  
As a demonstration, he would gather a crowd of people around his 
Model T and advance his timing with the lever on the steering wheel 
until the engine was pinging.  He would then take a little bottle of 
TEL and sprinkle a couple of drops on his NECKTIE!!  He would wave 
the necktie near the air intake of the engine and presto! The pinging 
would stop.  You wonder how long he lived, or whether he went mad 
from lead poisoning.  The lubricating effect on the valves was an 
unexpected benefit.

As for the change in overall mixture at altitude, I have to disagree 
also.  Air (actually oxygen) is going to be LESS dense at altitude.  
A carburetor works on Bernoullis principle, which depends on the 
speed of the air through a venturi, not its density.  Therefore at 
altitude at any given throttle setting, the airstream in the carb will 
be pulling the same volume of fuel into the venturi as it would at 
sea level.  But since there is a lower density of oxygen molecules at 
altitude, the overall mixture will be richer, not leaner as you 
mentioned.  Thats why SU specified an alternative lean needle for 
MGBs if they were sold in places like Denver or Tibet (Did any get 
sold in Tibet?).

Cheers, Paul Kile, Fair Oaks, CA (62 MGA, 74 B-GT V-8) 
an alternative lean  

Paul D. Kile

kile_paul@aphub.aerojetpd.com

(916) 355-5162
GenCorp Aerojet
POB 13222
Dept 5784 Building 20019
Sacramento, California 95813-6000

<Prev in Thread] Current Thread [Next in Thread>