Gascolator

[ykachuro]

This gascolator looks very interesting:
http://www.flyboyaccessories.com/product-p/72rr02.htm
Cold side of the firewall, might be the lowest point in the fuel system, easy access for drainage and filter cleaning. New product, so not much feedback, but there are some reviews on VAF.

[Seansull]

+1 for gascolator. I installed mine for my O-235 at the lowest point on my firewall. I have a cold air jet that blows on mine as well. Another advantage is having additional fuel in the lines forward of tanks. This will help alleviate fuel starvation during short inverted periods. Just something else to consider.

I will say, my FWF is VERY tight. I hope you have a friend with small hands!

[JimParker256]

A couple of years ago, I attended a presentation on fuel system design at OSH. The presenter (whose name escapes me at the moment, and my notes are elsewhere) was an engineer who was responsible for the design of the fuel systems for Boeing, so his credentials are impeccable.

He was quite adamant that EVERY light plane fuel system design should include a gascolator, which should ideally be installed at the lowest point in the fuel system piping. If you cannot install the gascolator at the lowest point, then you need to install additional drains at the lowest point in the system.

He was also pretty convincing in his argument against using the "flow-through" filters (such as we find used in autos all the time) in aircraft, unless those filters include a built-in bypass capability, AND provide some sort of notification to the pilot that it's being bypassed. He cited all kinds of examples of fuel system contamination (including the use of improper sealants for the tanks) that could easily clog up the small surface area of those filters, blocking fuel flow to the engine. Without a bypass capability, that results in immediate fuel starvation. And even WITH a bypass, if the pilot is unaware of it, the contaminants will pushed through the fuel lines to the carb (or injectors) where the ports can become blocked.

With a gascolator of sufficient size and volume, this is alleviated because the fuel flows into the gascolator body, where the velocity slows dramatically. The large screen in the gascolator has a LOT more surface area, so it would take a LOT more contaminant to block all the fuel flow. And finally, any contaminant in the fuel that is more dense than the fuel (and hence drawn through the fuel system instead of floating on top in the tanks) would settle to the bottom of the gascolator, and be far more likely to become visible in the fuel sample.

For those who still planned to use an automotive-style fuel filter without a bypass (against his recommendation), he strongly advised using one that has a transparent body, and installing it where it could be easily seen - preferably while in flight, but at least where it is readily visible during pre-flight, and to make it part of your scan (if visible inside the cockpit) and/or pre-flight to check it's condition as often as possible. It doesn't take much to clog one up, starving the engine of fuel.

Well, all I can tell you is his talk, pictures of clogged filters, etc. made a believer out of me, and I'm definitely installing a gascolator in any airplane I build – preferably at the "low point" in the fuel system.

Build safe to fly safe!

[colin]

Thanks for the replies. We are required in Canada to have a gascolator. The drain must be lower than the cowl as well. On my last projects , RV7 and Waiex I had to extend the quick drain with a nipple to get it below the cowl. I haven't purchased the exhaust headers for the Lycoming . I would assume they merge somewhat in the center of the cowl. That would let me position the gascolator on the hot side of the firewall biased to the left side . I have room on the firewall as I have the battery and electric's on the inside face of the firewall.

[ykachuro]

I was researching fuel systems and came to the conclusion that a gascolator with our set up might creat more issues than it would solve. However, since you seem to be in Canada, you may not have a choice but to install a gascolator as I understand it is a regulatory requirement in Canada. You might want to take a look at Andair website http://www.andair.co.uk/sport-general-a ... l-systems/ - it is showing gascolators on the “cold”side of the firewall. Although I am not sure we have space for this setup either.

[jamesmil]

Hi Colin,I found that there was very little room to mount a gascolator to the firewall with the exhaust and mounting the oil cooler on the firewall. Also I mounted what I call an oil slobber tank with drain on the firewall to. I installed an in line fuel filter by "Earl's" between the electric fuel pump in the cockpit and the engine. I use the drains in the fuel tanks religiously to check for water and it has worked well so far.

[colin]

Hi, I'm working on my firewall. I'm installing a 0-320 engine. Can anyone send o photo of the gascolator positioning for this build .

Thanks