gascolator

[DEWATSON]

I have installed an IO360 in my RV8. Reading the construction manual and reviewing the blueprints for the fuel system, I do not see where the gascolator should be mounted. Certainly one is required. Am I missing something or maybe overlooking it?

David Watson

[William Slaughter]

It's not uncommon to leave off the gascolator on fuel injected RV's. Give it a search - there was a thread on this recently which offered lots of varying opinions.

[DEWATSON]

Yes, I did the search and found the opinions. I should have done the search first. Thanks.

David

[Bob Ellis]

Hi David

I have based my gascolator (Andair 375) position in the fuel system based on the Extra 400, a certified competition aerobatic aircraft. Check out the link for a diagram and maintenance advice.

Regards

Bob Ellis
www.rv-8.co.uk

[Kevin Horton]

Originally Posted by Bob Ellis

Hi David

I have based my gascolator (Andair 375) position in the fuel system based on the Extra 400, a certified competition aerobatic aircraft.

Note that the Extra 400 is a normal category, non-aerobatic aircraft, as evidenced in this statement from the EA-400 Pilot Information Manual.

Originally Posted by EA-400 Pilot Information Manual section 2.10

The EA 400 is a normal category airplane. The normal category is
applicable to aircraft intended for non-aerobatic operations.

[roee]

Originally Posted by Kevin Horton

Note that the Extra 400 is a normal category, non-aerobatic aircraft, as evidenced in this statement from the EA-400 Pilot Information Manual.

...and the EA-400 is also a high wing aircraft, so there will be positive head pressure on the upstream side of the gascolator thanks to gravity. That will not be the case with a gascolator similarly positioned in the fuel system of a low wing RV. The aux fuel pump will have to suck fuel up through the gascolator, which may increase the potential for vapor lock.

[Bob Ellis]

Gentlemen

Thanks for pointing out my homer moment it is the Extra 300 I am basing it on which is a mid wing aerobatic aircraft with an acro tank below the wing tanks. Not sure why I had the 400 in my head? I do apologise.

Regarding the comment about "The aux fuel pump will have to suck fuel up through the gascolator, which may increase the potential for vapor lock" the Extra Aircraft designers seem to be happy with the gascolator between the fuel selector valve and the aux electric pump.

Bob

[w1curtis]

Originally Posted by Bob Ellis

...
Regarding the comment about "The aux fuel pump will have to suck fuel up through the gascolator, which may increase the potential for vapor lock" the Extra Aircraft designers seem to be happy with the gascolator between the fuel selector valve and the aux electric pump.

Bob

The difference between the Extra 300 and any RV is that on the Extra the gascolator is positioned lower than any tank in the system. It is below the main tank. Positioning the gascolator below any of the tanks, cannot be easily done in the RV. In order for a gascolator to be effective, and trap water, it needs to be lower than any tank. So unless it is a regulatory requirement as it is in Canada, it is of not much use on a low wing fuel injected aircraft.

The Canada regulation is just a hold over from when many engines were carbureted.

[Bob Ellis]

Hi William

I am not using the gascolator as a water trap in the RV due to the low positioning of the tanks, which have drains to do that job. I am using it as a filter, which Extra seem to be using it as well as I cannot see any reference to any other pre-pump filters on their diagrams.

Bob