RV-6 Gascolator Confusion

[Rob Erdos]

I'm currently populating the firewall of my -6 project with hardware, in eager anticipation of hanging the engine (TMXIO-320 with AFP FM-150 fuel injector). I plan to install my Vans GAS-5 gascolator on the lower-right firewall. I know... a gascolator isn't required or recommended for a fuel injected system, but the regs in Canada say otherwise, so I need one. (Oh, and just to avoid distraction, I know that some people put them in the wing roots, but I'm trying to avoid the duplication of something I'm not sure I need anyway.)

Confused! My FWF plans for the RV-7 (Dwg OP 28) show a gascolator installation on the firewall, backed up by a complicated-looking VA-161 Gascolator Bracket. Sources of confusion:

1. It appears that we can't use the VA-161 Gascolator Bracket shown on the RV-7 plans, as the RV-6 has a different firewall (extra doublers on the back of the firewall in an X-pattern). What sort of doubler or reinforcing plate is used to mount the gascolator on a -6?
2. Once it's installed, how is it accessed? Do we typically drill a hole in the lower cowl to take fuel samples? *
3. Further, despite Transport Canada's insistence on the issue, I see no reference to a gascolator in the Installation Manual from AFP for the FM-150 F/I System. Is there any problem installing one? Can I be confident that a gascolator can take the outlet pressure of the high-pressure fuel pump?

Your collective wisdom much appreciated,

Rob Erdos
Ottawa

 

[shamer]

Gascolator

Rob,

I had a gascolator on my -4 with Bendix injection that worked fine. It worked fine when I removed the gascolator as well.
I have a single Gas 5 on my carbed -6 located in the right wing root. It's a snug fit but easy enough to do. The fuel line routing is per the plans except for the engine supply line going out into the wing root through the gascolator and then back into the cockpit. The gascolator is bolted to the fuselage skin with a doubler plate. I have a plug in the wing root fairing to access the quick drain.
Servicing the gascolator is a bit of a problem because of the need to safety wire the four bowl screws. It has to be removed for servicing unless you make a simple modification. Replace the four 10-24 screws with 4 inch long screws with drilled heads. In my case, that placed the heads very close to the wing root fairing and I can service the gascolator and safety wire the screws without removing the gascolator. I duplicated the bowl hold down plate and installed spacers to locate it an inch and a half down the bowl. Two inch spacers below that plate help stabilize the screws.
Turn the fuel selector valve off before servicing.
I have pictures but won't be home till later this week if you're interested.

 

[GLPalinkas]

Mounting VA-161

Rob, here is how I mounted mine. Can't find the finished photos but I will when I have more time.

I made the bracket from some angle and mounted the gascolator on same. You have to use an extension to drain the gascolator from a small hole in the cowl.

More pics later if I can find them.

 

[terrye]

Fuel Pump Filtration

I know the regs for Canada regarding gascolators don't make sense but they say you gotta have one (or more?). I'm building an RV-9A with an injected engine, and I recommend you check the boost pump specs to see what filtration they recommend. In my case I am planning to mount an Andair GAS375 gascolator in each wing root upstream of the boost pump. I believe Andair gascolators are easier to service than the Van's GAS5 gascolators using a threaded collar instead of four screws. The other thing to check is the pressure rating on the gascolator, it needs to be sufficient for the boost pump pressure if mounted on the pressure side of the pump.