7A/9A: fuel pump to carb routing

[Paul Eastham]

Hello fellow builders (everyone stuck at home building during OSH),

Has anyone come up with a good combination of fuel pump -> carb routing, along with good exhaust placement?

I believe the recommended routing is shown below...sorry for the poor photo. Problems:

1. It rubs on both of those pieces of the engine mount, and not gently either.
2. Where to secure it, if it all? The hose/engine will be vibrating at both ends, but the mount won't be. There's also not a lot of room for slack to allow for the shaking engine.
3. The gap to the exhaust seems somewhat small (other builders have expressed concern) -- and this is with the exhaust pushed down and out leaving only a 1/8" gap to the cowl. Too little?



Other routings (namely "inside" the engine mount) keep it further away from the exhaust, but seem to put more stress on the fuel line and rub the mount harder.

Thanks for sharing any success stories you've had in this area.

Paul

[vlittle]

Here's how I did it. You can adjust the attachement angles at both ends to route the hose. I ended up with a second heat shield, just for extra protection.

Vern Little

[George in Langley BC]

Hi Paul

Hard to tell from your picture, confirm you are attached to the left (pilots side) of fuel pump. Line should not rub on engine mount and you may need different fittings or hose to make the line stand off more from carb.
My fuel line came from Aerosport Power with a 90 degree elbow for carb end and has at least 1/2 inch clearance from engine mounr tubes and exhaust pipe.

I am going to try and attach three pictures.

[Paul Eastham]

Yes, left side of the fuel pump. I too am using the hose and hardware that Aerosport provided: 90 degree at the carb, and straight out from a tee at the pump.

1/2" from the mount tubes, huh? I just can't see how that's possible. Your pictures didn't come through...

Originally Posted by George in Langley BC

Hi Paul

Hard to tell from your picture, confirm you are attached to the left (pilots side) of fuel pump. Line should not rub on engine mount and you may need different fittings or hose to make the line stand off more from carb.
My fuel line came from Aerosport Power with a 90 degree elbow for carb end and has at least 1/2 inch clearance from engine mounr tubes and exhaust pipe.

I am going to try and attach three pictures.

[sf3543]

Why not move the fuel line to the other side of the engine mount tube. You can use a stand off to hold the line in position...use 2 adel clamps, one on the engine mount and one around the fuel line. If you want, use an over size clamp around the fuel line to allow movement if there isn't enough slack in the fuel line. (Since the engine will move independently from the mount.) The fire sleeve should prevent any chafing on the line itself.
VAN's sells self stick aluminum sheet to place on the cowling to avoid burning from the exhaust. I have some on my RV8 cowl where I was getting a brown mark from the exhaust. It works great.

[Paul Eastham]

i just noticed on Andy Karmy's site that he uses a 45-degree fitting at the carb. I tried it out and the routing is much improved (going outside the engine mount now) -- it's higher up and away from the exhaust, and plenty of clearance from the engine mount tubes.

I also looked at the plans -- oops, that's what Van's calls out anyway! Aerosport seems to provide the 90-degree for some reason...

Paul