Advice on Rv3 header tank.

[Mycool]

Hello all,

I have a rv3 with a header tank only and am rebuilding an 0-320. I have two rear accessory cases, one with fuel pump and one without.

I am considering not putting a engine driven pump nor boost pump, just to keep it simple. The header tank is at least 2-3 feet above carberator.

Any wisdom or considerations on this setup are welcomed.

[Raymo]

An electric boost pump can also help overcome vapor lock.

[David Paule]

You could do a flow rate test without the pumps and then,
with data in hand, make a decision.

Dave

[Caveman]

Tread carefully here. Many amateur built aircraft accidents are caused by modifying fuel systems. I'd stick with the plans...

[agirard7a]

I use to own an Rv-3. It had a center tank and Engine driven pump.
The plane was 160 hp and weighed 800 lbs. Needless to say, I could climb out at a very steep angle if needed. I would highly recommend the Engine pump or an electric pump. The steeper you climb, the less differential pressure in the gravity feed system. Unless you where able to do an elaborate incline flow test and know for sure, just use a pump.

[Mycool]

I just got off the phone with Lycoming and they stated min 1/2-3 lbs and 6lbs max of fuel pressure.

Agreed, keeping the engine driven pump is good security.

I plan to do a pressure test of the tank to carb inlet pressure with minimum fuel. Is there any easy way to take pressure reading of that fuel head pressure?

[rvbuilder2002]

Originally Posted by Mycool

I just got off the phone with Lycoming and they stated min 1/2-3 lbs and 6lbs max of fuel pressure.

Agreed, keeping the engine driven pump is good security.

I plan to do a pressure test of the tank to carb inlet pressure with minimum fuel. Is there any easy way to take pressure reading of that fuel head pressure?

Do some research on converting PSI pressure to inches of water, and then research making a home made manometer.

Just don't forget to put the airplane in a 45 deg nose up attitude when you do the test. Even if it still passes, it would probably be a good idea to put a placard on the panel saying "Not approved for aerobatics"

[Rick-CAS]

My RV-3 did not have the engine driven pump when I bought it. It did ok but it would cough if power was reduced quickly and the nose pushed over. It coughed once in a takeoff climb and I decided it was time to install one. The first time I flew it to Oshkosh I got to talk to Van himself since he was the only one that could answer RV-3 questions. That was his first question to me did I have an engine driven fuel pump. I said no and he said go to the ACS booth and order one. I now have tube type wing aux tanks and it requires the pump. I highly recommended not going the gravity feed route.

[Mycool]

Done deal, I?m putting in an engine driven pump.

Thank you.