Hi Kingsley
Carburetors mix fuel to air by volume of air. Going up in altitude decreases the
number of air molecules per given volume of air a lot more than the decrease
in temperature. Thus since there are less air molecules for a given amount of
fuel the mixture will be richer than optimal. I will speak general but often
full throttle will provide a richer mixture than less than full throttle. The
reason is to cool the fire by throwing more gas on it! I have a 914 which
complicates
the life of the poor Bing type 64 constant depression carbs but am installing
a Hacman that will work on the 914. Have not yet tested but should be
fine. Mind you if you have control of mixture it can be a good thing, but if you
run hard and lean that can be a terrible thing. If you lean at altitude when
you come down or pull the throttle it will be leaner than desirable so you will
need to add this extra bit to your piloting tasks.
see Mixture 1 and 2
http://www.europaowners.org/main.php?g2_itemId=27305&g2_page=2
I am installing 2 EGTs and a Split Second monitor. It uses a O2 sensor to drive
it. It allows you to monitor mixture. Unlike a fuel injection system that needs
very fast response time of the O2 sensor, using one in this capacity only needs
a very slow response time. Thus even using Leaded Fuel, should be able to
get 100 hours out of O2 sensor from what I'm told.
Ron P.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=493790#493790
|