RE: Stainless Hose routing for UL 350i engine on CH750 Mike Adamczyk 1/31/13

Ken,

Sorry for the delay in replying, but I have just finished mating the fuselage and wanted to be sure that I had no fuel line hiccups before I answered your question on UL Power and fuel hose/valve selection.

I am looking for reliability and low maintenance, and I chose to use stainless braided Teflon hose with AN fittings and hose ends, vs. the supplied rubber lines and hose clamps that require periodic replacement. With the fuel injection system used on the UL power, excess fuel from the electric fuel pumps is returned back to tank. In the case of the CH750 that means either the selected RH or LH wing tank, or a header tank.

I chose to use an Andair ‘duplex’ fuel selector valve rather than the electrically operated fuel selector valve supplied with the FF kit (incompatible with AN hose ends). The Andair valve has three positions: LH tank, RH tank, and off. Excess fuel is returned to the tank selected. I did not use a header tank.

Fuel Selector Valve /AN fitting Selector Valve mounted Console

Routing of fuel lines, gascolator, brake lines, pitot lines, and wiring

Pilot side fuel line routing to wing Passenger side fuel line routing to wing

I ran the hoses outside the vertical channels, it is just too tight to get them inside. Clamps are from Summit Racing, into nut plates. The stainless hose and AN fittings are also from Summit Racing.

Pilot side bulkhead fittings to wing Passenger Side Bulkhead fittings to wing

Fuel lines to firewall bulkhead fittings - supported by strap and T- clamps

Firewall side, fuel inlet to electric fuel pumps. AN fitting tig welded to manifold

Suggested changes: or what I learned the hard way.

While I am happy with what I ended up with, if doing this again I would change the location where the fuel lines enter the baggage compartment floor. Bringing them in where I did was OK, but made for a very tough time getting the bolts into the landing gear strut fittings. This was complicated by the fact that I had already riveted in the baggage compartment floors. I would move them aft 2- 3 inches to provide easier access to the bolts/nuts, and fabricate a cover to close off that area of the baggage compartment.

Congestion of lines on Pilot side – interferes with assembly of gear strut fitting bolts/nuts

Move fuel & pitot lines thru floor aft 2-3 inches Fabricate cover for fuel lines

The only downside that I can see of using the Andair duplex valve, braided Teflon hose, and AN fittings is cost. This route is definitely not cheap, but hopefully this will give a long and trouble free operating life in exchange.