EAA 292 Chapter Meeting Jan 9, 2021 Presentation - Apex powered Zenith 701

Chapter 292 member Dwight Hoover discusses his efforts to fit a 150 HP Yamaha Apex engine onto a Zenith 701.

[@patway4683]

Wondering if Dwight is able to be contacted? I am doing this same engine setup and wondering how it worked out for him.

[@HeeHawHighlander]

Make sure Dwight knows you only run one fuel pump at a time on the Apex, the other is a back up.

[@GTgyro]

I've been doing Yamaha 4-cylinder conversions since 2011 and build the only 165 HP Yamaha EXUP aircraft conversions known to date, on gyrocopters. My conversions can run two water pumps in parallel, no need for a panel switch to swap them over and restart a fuel-starved engine in the event of pump failure. I use an adjustable fuel pressure valve set at 45 psi and run the overflow line back to the primary fuel tank, not an upstream fuel line.

[@Mike-01234]

Most modern FI uses high pressure pumps that are installed in gas tanks. In non auto application I would think a header tank would be proper with that in-tank pump then two other pumps that bring the fuel from the wing tanks to the header tank with return lines. I know issue with a high pressure FI pump they can burn up if they run dry they use the fuel to stay cool. Then have a regulator to keep the pressure constant 30-60 psi whatever.

[@GTgyro]

The purpose of putting a pump inside the fuel tank is not for cooling the pump. Example, in trucks the pump in the tank is merely a sending unit to prime the main pump in the engine compartment. In Yamaha snowmobiles - where this engine comes from - the pump is inside the tank in order to eliminate a return line. As to starving the pump of fuel and worrying about burning it up, in an aircraft that is the least concern you'll have - after you've crash-landed from starving the engine of fuel...