Johnkpap,

I did not get an response on my post, maybe you didn't read it yet but it is also possible you do not know how to measure the difference in fuel consumption.

I have an idea:

Adjust max power with the fuel level as low as it can be in vertical nose up flight in your Arrow.
Then bring the tank in normal level position, as you show on the bench and shut of the main tank, the fuel will be used from a little second tank,
Measure RPM and time.

Compare these values of both engines.

We all expect the "pumped" engine will do it better but I want to see results before advice.

I normally do not believe these phrases:
The porting on "Franki" was done by a "Expert" to get that much of a power gain and still get a reasonable Idle, any Idea
on who was doing porting work in the 80's on pattern engines ?

Because for example "Franki" can be a power boat engine, or ducted fan!



After the test show us the same with 50 % power or RPM.

After you show us the values we can think with you about the engine to use.

I do these tests with tankpositions far above and below the positions that are normally possible in my plane!
I want for any tank position the same result, full power, 50 % and idle for at least the periods that are possible during flights.
Nose up full power no limitation of time, horizontal either.
For idle and nose up, I have time limit because the tank has to be the pressurebuffer. That is because I do use a check valve between exhaust (pressure controller, when used) and tank, the exhaust pressure is to low.

Cees