Before this morfs into how the innkeeper built his homemade fuel
pumper, I thought I would post the answers. I'm surprised many more
didn't take a shot at this but then again, it's not regular hangar
chat. How well did you do?

EGT = Exhaust Gas Temperature
CHT = Cylinder Head Temperature
ROP = Rich of Peak
LOP = Lean of Peak
(and I should have listed this earlier, sorry!)


The lower octane should cause a faster overall burn time and short
interval to peak pressure - - and that should result in lower EGTs.

For the same reasons, the peak pressure increase should cause higher
CHTs.

And the horsepower ?? It probably would not change much... 1-2 % .

The overall effect is the same as if you had improperly advanced the
timing 3-7 degrees.

Regards, George

Contact George at gami.com for any further explanations.






Ok... little MOGAS quiz for you.

You run the Left tank dry and fill it up with premium unleaded car
gas.

Right tank has 100LL.

Takeoff on the RH tank and climb, level off, and set up the mixture
for
cruise flight. Either ROP or LOP. Your choice.


THEN, you switch to the LEFT tank. You change nothing else.

Later you download your JPI and plot the data.

1 What is it going to show happened to the EGTs when you switched
tanks?

2 What is it going to show happened to the CHTS when you switched
tanks?

3 (not in the JPI, but: ) What is the airspeed going to do? Increase?
Decrease? Stay the same?

Why?