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RV-4 Gascolator mounting

sslayden

Member
Does anyone have a method of mounting a gascolator on the firewall or engine mount in an RV-4 that does not require machining or welding together a fancy bracket or mount?
 
Can you use the new Gascolator from Van's?

I just requires a backing plate on the inside of the firewall.

Here's a picture of my gascolator, as installed in my -9.
 
No room to mount directly to firewall

Unfortunately, there is not room to mount it directly to the lower firewall. The engine mount is in the way. I've seen some builders make a piece that extends the gascolator out from the firewall so that it will clear the engine mount. I've seen a couple of implementations:

Dayton Murdock milled a very nice piece: http://www.mykitlog.com/users/workl...=n9174l&project=74&log_id=7086&photo_number=1

Phillip Mercier make some spacers. This seems a little more do-able for me:
http://members.toast.net/pmercier/project2/photos-6/00116.jpg.html

I'm wondering if there is a 'standard' or common way this is done on the rv4. Anybody know?
 
Necessary?

Does the 4 NEED one at all? Low point is the drains in the wings. If you never sump the wings, then yes, it might catch some water I guess. A filter is a good idea, but someone help me understand why the four needs a gascolator. Especially ABOVE the wing tanks. Probably obvious, but right now I'm missing it.
TIA
 
Dirt...

Hi Dennis,
We've done two annuals/condition inspections on our -6 and each time I disassembled the gascolator there was dirt in it. Not much, for sure, but that would have gone through the carb. A gascolator is just cheap insurance.

Regards,
 
In my -4 I placed the gascolator on the lower right side of the firewall, just to the left of the exhaust pipes coming off of the #1 and #3 cylinders. I have the standard Vans gascolator but it is attached to a mount that I made from scraps of aluminum that are riveted together and it is surprisingly strong. This mount is held to the firewall with four screws. It was a tight squeeze but it is the lowest point in the fuel system and doesn't hit the mount or anything else. I think I posted a picture of it on this forum some time ago. Let me know if you are interested and can't find the picture. I'll post another one.

Alan
RV-4 N7028K
 
Alan, I found the pics you posted. The last pic in a series of three you posted shows the gascolator mount a little. It looks good from what I see but I can't tell how it's made. Did you make a box structure out of aluminum sheet or did you use angle. I can't tell. Do you have a better picture?

BTW, the oil cooler mount looks very good, too. How is it working out? I might copy that also :)
 
On my RV-4 I made an mount for the gascolator out of aluminum angle. I then drilled bolt holes in the other leg of the angle. I then attached this via adel clamps to the bottom cross tube on the engine mount. This also allows the drain of the gascolator to hang below the level of the lower cowling just slightly so I can drain it before flight. I can send a picture if you want.
 
1,000 words

Here you go Steve....a picture is worth a 1,000 words.

dsc00259zr1.jpg
 
My gascolator mount is made from thin aluminum that I bent to shape. If I remember right it was made from scraps left over from the elevator skin (0.016" thick I think). No machining was required and the mount is plenty stout. I'll get some more pictures for you this weekend.
The oil cooler is similar to someone else's I heard about. Smokey Ray's I believe. From what I have read about Smokey's set up, he had some high oil temp problems with the cooler mounted to the back of the baffles. He then did the canted set up and finally had to move it to the front baffle. I have heard that a 3" scat tube to a remote site works but I didn't have room for that. I have a 2.38" dia. hole through the aft baffle leading to my canted oil cooler plenum. With the smaller diameter hole, all of the air comes from above the #4 cylinder so that theoretically I don't get any preheated air to the cooler from the cylinder. This hasn't flown yet but should within the next few months. I'll see if my theory holds up.
Alan
RV-4 N7028K
 
My own thoughts sit between Dennis and Pierre's posts below. To drain water off, by far the best place is the wing drains. That is where you will catch it. However, I did want a filter to get any dirt out of the system.

Since injected engines are filtered in the cockpit I could not see why I should not use a Andair gascolator as a filter. I wont normally run off fuel there before flight, because of the risk of stink. I will dissasemble from time to time to check for dirt.

To me this seemed to serve the needs I have,and prevent the gascolator acting as a cooking pot to heat the fuel. It also simplifies installation and parts.

You can see it in the middle picture here: http://gikonfuse.blogspot.com/2008/01/fuel-system-inside-fuselage-is-complete.html#links

or:http://gikonfuse.blogspot.com/2007/03/fuel-valve-gascolator-and-pipework.html#links

Just an idea, but sorry, it does not answer your question.
 
I mount mine in the cabin in the stick bay. The drain extends through a grommet in the belly skin. It is easily removed for cleaning. This keeps the unit out of the heat and vibrations of the engine compartment. I have installed eight units like this and all are working well.

The picture was taken from a rocket but I used the same installation in my RV4
 
I mounted my Andair gascolator just as a filter inside the cabin to avoid heat, vibrations, vapor lock, and all the nasty things. All that runs from the firewall to the Ellison TBI is one hose, primer and filter are inside the cabin. Works great, and if you want, you can extend the drain valve of the Andair unit down to the belly with a simple tube (I did'nt do that).
dscc06210.jpg
 
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