How to Measure Fuel Tank Vent Pressure

Experimental aircraft builders often test their fuel system for adequate venting and fuel flow while on the ground. Vents can behave quite differently while speeding through the air - possibly decreasing or increasing the vent pressure. This can radically change fuel flow in flight. When determining the proper position for fuel cap vent snorkels the desire to measure vent pressure in flight is needed. Tuning engine cowls for best airflow also requires knowledge of small pressure changes. This video discusses the use of an inexpensive digital manometer to aid the homebuilder in analyzing their fuel vent system.

[@keepyourbilsteins]

Used to have to use slack tube manometers. Nice there are digital instruments now.

[@DJ-mo2ur]

I would like to see more tips regarding an all wood aircraft. You seem to cover mainly metal built aircraft needs but I'm glad I subscribed to your video's

[@TheGarageBandSyndicate]

Hi temp sealant could help on those small gaps at the base of the cylinder heads. I saw Mike Patey do it recently on his high side pieces. Also a reverse scoop on the low end would help generate a vacuum to assist with pulling the air along with it being forced

[@coloradocruzer]

Love your videos. Not sure if the "air must travel the same distance" graphic was put in ironically!

[@michaelguy7168]

Very helpful, thank you.

[@USA-GreedyMenOfNoIntegrity]

Use it for a Lift Reserve Indicator. Use it to tell you when your home HVAC filter is needing replaced. I used one that I use for gas furnace pressure testing to test my fuel tanks for leaks. 1.000 psi max. No leaks and still no leaks 10 yrs later.

[@billr8667]

Looks like you got spammed (see comment below).