Comment

Comment by Bob Pustell on June 1, 2012 at 9:54pm

I am not a Viking expert, but I do know that the Viking has a flywheel (which the Jabiru does not) so I expect it can get by without the flywheel effect of the propeller. The flywheel is attached to the engine and is part of the reduction drive.

 

Most aircraft engines do not have a flywheel so the spinning propeller serves that purpose. Also, most aircooled aircraft engines depend on the propblast for cooling when not in flight. Therefore, most aircraft engines need the prop installed even for ground runs.

 

A friend just did the first engine run on his AeroVee powered Sonex, and did it without a prop. The AeroVee also incorporates a flywheel. Since the AeroVee is aircooled, he had to build a wooden stand over the engine and mount a couple of electric fans to cool the engine (no prop blast) but it worked fine.

Comment by Steven Winn on June 1, 2012 at 9:45pm

Viking says no problem running without prop. They made a video of Dan Stanton's engine (I think) doing it.

I assume it's ok due to the "flywheel" fan.

If you couldn't, it seems that it would beat the reductions gears to death.

I wonder if you can run a Rotax without a prop?

Comment by Ian McClelland on June 1, 2012 at 8:51pm

OK Looks good. Does Viking recommend running without a prop? Jabiru says don't do it, not sure if that would apply to the Viking?