Flygas mechanical fuel pump for the 914?

Hi Joe

As I read the specs it is a very high RPM pump, not a typical diaphragm type as used on the 912.  It is intended to drive direct from the crankshaft as a replacement for one of the electric pumps.  I guess if you have room and some space cash it will work.  By the look of it you need to have clearance on the flywheel side of your engine.  it also looks like they will charge you a lot for it, i did not look up the price.

Cheers

I hope their engineering/craftsmanship is better than that of their english-language marketing material...

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Tyler Hathaway wrote:

I hope their engineering/craftsmanship is better than that of their english-language marketing material...

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Their English translators have much reliability, just like their products!

Rotax Wizard wrote:

Hi Joe

As I read the specs it is a very high RPM pump, not a typical diaphragm type as used on the 912.  It is intended to drive direct from the crankshaft as a replacement for one of the electric pumps.  I guess if you have room and some space cash it will work.  By the look of it you need to have clearance on the flywheel side of your engine.  it also looks like they will charge you a lot for it, i did not look up the price.

Cheers

So the fuel flow and pressure values at the listed RPMs is safe for operation in a 914 assuming they are reported correctly? I've been looking into the 914 since I want turbo and the 915 is too heavy but I don't like the reliance on an electrical system with limited redundancy. In theory it is protected against failure (voltage = 0) of either generator OR battery but if the regulator fails and the generator delivers full 40V (assuming it's the same as the ULS), an EarthX battery will shut off to protect itself and PbE battery will just die in time leaving no power for the electric fuel pumps. With electric pump in addition to mechanical pump then the worst possible electrical scenario is failure while wastegate servo is in full boost position but the engine will still run (I assume servo doesn't spring back if power is lost).

With the 914, if you get the external alternator you can run ONLY your main pump off of the internal generator, keeping it completely isolated from the auxiliary pump (and airframe electrical bus). In this case, the catastrophic regulator failure you describe would not have any effect on the auxiliary pump, the battery, or the airframe electrical system.