McFly

McFly

Well Known Member
I am looking for pictures, websites, ideas on draining the gascolator with the cowling on. Bonus points if the gas drains outside of the plane ;) Thanks.
 
Hugh,
I don't have pictures, but I used a combination of 45 degree fittings to extend the drain down to the lower level of the cowling.
 
I drilled a 1.25" (or thereabouts) hole in the cowling and glassed the exposed edges. I simply stick the little fuel sampler through the hole and drain a sample. Works like a charm.

That said, I won't bother with a gascolator on my next plane. I've never found any junk or water in mine, and I think it acts as a heat sink to transfer under-cowl heat into the fuel in the bowl. Perfect for contributing to hot starting problems and/or vapor lock.
 
I did like Mel, extended the drain down to the bottom, and drilled a hole in the cowl flange - except I didn't use 45 fittings - just bent the tube!

And just like Kyle says, unless you turn the fuel pump on, you can't get anything out of it anyway.

My old Grumman AA1B didn't have a gascolator, and it came from the factory that way. I almost didn't put one on the RV, but reading through accident reports for experimentals showed dismal results for modified fuel systems - even though I knew this would be a minor change, I had pledged to build that part of the aircraft the way Van intended...(but would probably decide different next time).

Paul
 
I've never heard of a certified airplane without a gascolater. Are you positive the AA1 doesn't have one? I know the AA5's do.
 
osxuser said:
I've never heard of a certified airplane without a gascolater. Are you positive the AA1 doesn't have one? I know the AA5's do.
Click to expand...
Yup - unless it was hid REALLY well. I owned the plane for 23 years, and did a complete FWF upgrade to a larger engine early on. No gascolator anywhere. (I just re-checked the parts manual too...) A lot of "interesting" things about that airplane's certification. The carb heat cable, for instance, was a lawn mower choke cable. But once it became part of the certificated design, that was the only legal replacement - and they weren't made anymore.....

Ahhh...the good old days!
 
Ironflight said:
Yup - unless it was hid REALLY well. I owned the plane for 23 years, and did a complete FWF upgrade to a larger engine early on. No gascolator anywhere. (I just re-checked the parts manual too...) A lot of "interesting" things about that airplane's certification. The carb heat cable, for instance, was a lawn mower choke cable. But once it became part of the certificated design, that was the only legal replacement - and they weren't made anymore.....

Ahhh...the good old days!
Click to expand...
I know all about that kinda stuff, ask about Cessna Cardinal inside door handles sometime... '60's fords.
 
i drilled a 1" hole in the bottom of the cowling and installed a camloc access door from AC spruce (KM713-16-064) to cover the hole.

works great!
 
2" brass tube and couple

I saw on another builder's website where he used an extension tube to drop the drain plug down, so I went to Lowe's and found the parts: 1/8"x2" brass pipe & Female couple. This drops it down so the drain plug will exit the cowling. Might be better if there was a 2 1/2" pipe available.

Mike
 
Gascolator drain

Here's the way I did mine on my -8. I apologize for the picture, only one I had. The quick drain itself is just outside the cowl when it is on the plane. I think it's kinda self explanatory, but if you'd like a lengthy explanation, and a list of fittings, shoot me an email!



Good Luck!!
 
Drain valve

I machined an AL bar to just slip over the end of the drain valve (press fit, actually) far enough that it could be swaged on. I bored through it with about a 3/16" hole (don't remember exactly) and machined the bottom end down to around 5/16". I cut a 1/2" hole in the bottom of the cowl and let the extended valve stick straight down and out about 1/8". The only thing you have to watch is that you don't push the valve when installing the bottom cowl. Took about 15 minutes on a mini lathe, cost only pennies and is easily activated.

Bob Kelly, Scipio Indiana, RV-9A, Painting
 
I'm flying a friend's Grumman AA1-B right now and spent 30 minutes trying to find the gascolator the first time I flew it. It sure enough does NOT have one.
 
The wing root tank drains are easy to get at and they are the "low point" of the fuel system.

It just seems to me that the addition of a gascolator is Ok, but its modification for regular use may actually be dangerous.

Adding a "stalk" to get the drain down to the exterior of the airplane is asking for trouble. Vibration and complexity are two of the main enemies of any fuel system and the addition of the extension might well violate both of them.

Just making sure to drain the gascolator at each cowl removal and always draining the wing tank drains after fueling and before each flight should suffice.

cl
 
Gasc O'later

Here's my thousand words. I later extended it further with a 1-1/2" nipple instead of the 1" shown. All parts from Home Despot.

Vern

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