gascolator - to use or not to use

[Jeff R]

I know that many builders do not install a gascolator with a fuel injected engine. I have been working ahead a bit on my firewall for my IO-320 and noticed the Van's installation does not include a gascator. My local tech counselor advises a gascolator, not so much for the water capturing, but simply as an extra fuel filter. My thoughts are that I could put a finer mesh filter in the secondardy gascolator filter to catch whatever might pass through the pre-boost pump filter. I guess a consequence of this, however, is that the Van's supplied flexible fuel line that runs from the firewall bulkhead fitting to the engine-mounted fuel pump might be too short.

Just wondering what the pros and cons are to installing/not installing a gascolator.

[Geico266]

I would consult the maker of your FI system. I don't know if a gasolator is rated for FI fuel line pressures. Make sure it is if you use it.

[Jeff R]

Good point. I have an Usher unit that says it can be used in FI systems up to 50 psi. The boost pump is the AFP one that Van's sells, and the engine pump is whatever Lycoming puts on their experimental IO-320 (I haven't received the engine yet).

[Kyle Boatright]

Gascolators are big heat sinks. They provide one more conductor to transfer heat from under the cowl into your fuel, contributing to vapor lock issues in hot weather. I have one, have never found any trash or water in it, and would not install one if I was doing things over again.

[asav8tor]

The other thing is the drag on the system. If you use the electric boost pump for takeoff and landing, when it is off everything on the input side of the engine driven pump is under neg pressure, suction if you will. This fact alone without the heating issue moves you closer to making bubbles. If you add a filter in-line from each tank (not a bad idea), then suck the fuel through the selector valve, then suck it through the electric boost pump, then through a gascolator until it finally reaches the engine driven fuel pump....... you have incrementally reduced the final line-in pressure to the point where Mr Bubble starts to have his way with your fuel flow.

Start heating the gas in the gas heater (I mean gascolator), run car gas with alcohol and you now have done everything possible to make bubbles in the line. If you still don't get vapor lock after trying all the above, I would like you to select some numbers for me to play in the next lottery game.

[Jeff R]

OK, some excellent points I had not considered. Given your advice and the fact that Van's doesn't recommend doing it, I guess I will place my gascolator up for sale. Thanks guys.