Notatestpilot
Pre-takeoff checklist
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- Aug 31, 2020
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Notatestpilot
Don't use it. As Nauga says, you can't monitor it or drain it before flight.Nope!
My RV6....thanks.
I don't think anybody makes a clear bowl gascolator for airplanes any more, might have been an AD to replace the glass with a metal tube? Only glass ones I've seen in recent years are for small engines and antique cars, with no drain.Transparent lower container on most models, to see the water or debris, some are metal, must be drained to see what is there, or, not there
Integral drain to remove contaminants
Outlet at the top to the engine, will not pass water until filled
In the rv’s, you’re gonna find any water in the fuel when you sump the tanks. Beyond that, gascolators are a really good way to add heat to your fuel and cause hard hot start and other warm fuel problems.Interesting so many use this sort of filter. I'm a big fan of experimental but apart from a few aforementioned specific use cases, why divert from the well trodden path in such a critical component?
They are common on the sonex line of aircraft. A gascolator doesn’t work with the aerocarb because the aerocarb needs to be the lowest point in the fuel system with a straight downward sloping line from the tank or else vapor bubbles cause the engine to stumble. These in line filters are the only thing that works in the limited space available and are what the factory uses instead of a gascolator now. Standard practice is to replace them every annual. There is also a tank finger strainer before the fuel gets to the filter. Some have also used the ones with a clear housing that can be inspected before flight but they are not made as well. The sonex is a pure gravity fed system so if you have a fuel pump on your RV then your experience may be different. If a gascolator works in the standard RV setup I also wouldn’t recommend deviating from it unless there is a really good reason.
My comments were specific to the aerocarb. A marvel Schebler carb has a float bowl that allows for any air bubbles to not interupt the engine. The aerocarb has no float bowl so any interruption in fuel flow, even a small vapor bubble interrupts the engine and makes it stumble. I don’t recommend it for an RV but that is why many Sonex use that inline filter instead of a gascolator.I just wanted to put in my 00.02 to say that my particular gravity fed aircraft with a Marvel Schebler carb has a gascolator ...
My comments were specific to the aerocarb. A marvel Schebler carb has a float bowl that allows for any air bubbles to not interupt the engine. The aerocarb has no float bowl so any interruption in fuel flow, even a small vapor bubble interrupts the engine and makes it stumble. I don’t recommend it for an RV but that is why many Sonex use that inline filter instead of a gascolator.
I have one. It came off my Jodel. That glass cylinder was 1/4" thick but I still didn't trust it. The head was cast zinc, so the total weight was not airplane-friendly. They were meant for tractors of the 1930s and '40s. I machined an aluminum gasolator for the airplane.I don't think anybody makes a clear bowl gascolator for airplanes any more, might have been an AD to replace the glass with a metal tube? Only glass ones I've seen in recent years are for small engines and antique cars, with no drain.
Some say there is, but I have seen stainless sheet riveted to aluminum, chiefly as firewall sheet to aluminum fuselage. After many decades it's still there in every airplane I've worked on. I've also seen stainless fuel fittings used in aluminum bulkhead fittings in large-aircraft tanks. Then, of course, there are the many stainless exhaust systems bolted to aluminum cylinder heads. Sometimes the flange gaskets are stainless, too. In Lycomings, the spark plug threads are a stainless Helicoil in that aluminum head.Any concern with SS bolt into aluminum threads? Galling? Galvanic corrosion? Or is there a threaded fitting in the top?
Any concern with SS bolt into aluminum threads?
But the critical time when the gascolator is needed is when the airplane is NOT in gorund attitude. That's when the fuel is flowing from the tanks to the engine, and the gascolator does indeed trap moisture and debris. As a mechanic and commercial pilot I've seen it often enough.i have been using the summit version of that for 22 years, never found more than a few specks in it when i clean it. a gascolator on a tailwheel aircraft is just a heat sink. it does no good, as it is not at the low point of the system.
On all of the [tailwheel] airplanes I've owned (Taylorcraft, Kolb, Fisher 404, Starduster, Hatz, Parakeet), the gascolator was indeed the low point of the system, both in flight and on the ground.a gascolator on a tailwheel aircraft is just a heat sink. it does no good, as it is not at the low point of the system.
The reason “low point in the system” matters is because it gives you head pressure when you sump the gascolator. No head pressure = no flow. The important things about a gascolator are the screen and the fact that the bowl acts as a small reservoir and allows water to precipitate out to the bottom of the bowl where it will not be picked up and sucked (or pushed) downstream.On all of the [tailwheel] airplanes I've owned (Taylorcraft, Kolb, Fisher 404, Starduster, Hatz, Parakeet), the gascolator was indeed the low point of the system, both in flight and on the ground.