Fuel flow transducer before or after vapor lock?

Re: Fuel flow transducer before or after vapor lock?

by Przemysław Wiśniewski » 11 years ago

Przemysław Wiśniewski

65 247 3

Ok, but if the last method can cause any problem with vapor lock?
I'd like to tow gliders by this plane so sometimes I will fly on about 4800 for cruise and sometimes 5400 for towing. Calibrating for one rpm will not be good for me.

Re: Fuel flow transducer before or after vapor lock?

by James Ott » 11 years ago

James Ott

22 364 524

I doubt whether the accuracy difference between 4800 and 5400 rpm would be noticeable. You shouldn't be cutting your fuel management that close anyway. Calibrate it at the higher rpm, then at the lower rpm it will show slightly higher fuel usage than actual, an error on the safe side.

I don't see how it could cause any vapor lock problems no matter where you mount it. The xducer is just a block with a full size hole in it with a free turning turbine wheel in it. Restriction to flow is nearly zilch.

Re: Fuel flow transducer before or after vapor lock?

by Roger Lee » 11 years ago

Roger Lee

133 5.49k 5.76k

You should not be getting any vapor lock while flying. You should have the re-circulation line, the engine should be moving more than enough cool fuel for this not to happen and you should have all your oil and fuel lines in fire sleeve and not really for insulation purposes the fire sleeve does help.

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Roger Lee
LSRM-A & Rotax Instructor & Rotax IRC
Tucson, AZ Ryan Airfield (KRYN)
520-349-7056 Cell

Re: Fuel flow transducer before or after vapor lock?

by Przemysław Wiśniewski » 11 years ago

Przemysław Wiśniewski

65 247 3

James, some of them has restrictors but FT60 not, it's fully opened. So I can see that is shouldn't be a problem to install it after vapor lock.. I'll think about this. I have all fuel lines in firesleeve.

Re: Fuel flow transducer before or after vapor lock?

by Mike Goodrich » 11 years ago

Mike Goodrich

8 123 0

The way I read the drawing you posted, the transducer will only see the flow to carb No1 plus the return to the fuel tank. The flow to carb No2 will not be measured by the transducer.
Please correct me if I'm not understanding something with your system.
Mike G