This engine is sold via Hobby King for a pretty low price which makes it pretty attractive. The example I bought came through OK, but apparently on its long boat ride across the ocean to the US warehouse, some of the screws and stuff picked up a little corrosion. Nothing serious, just a bit unsightly though.
The engine came with all of the basic stuff needed. Some hardware, motor mount extensions, screws, CDI ignition and some unknown brand of CM-6 type of sparkplug. The instruction sheet stated a 17x8 prop would be about right for it. But the LHS only had a Xoar 17x8 wood prop, so I got that.
I ran three propellers on the engine so far. I plan on trying out some others though. I want to see what a 18x8 prop would do. As the engine seems to really like bigger props on it. But the 17x8 Xoar prop worked pretty good though. According to Pe Reivers' Prop/Power spreadsheet the engine is developing about 2.3 hp to 2.4 so far and it has only hadseveral tanks of fuel through it so far. Plus the fuel had too much oil in it as well as I didn't want to go easy on the oil at first.
I am planning on using the engine on a huge 1.20 sizeSeagull Gee Bee Z plane that I bought a few years ago.
Propeller RPM numbers so far gathered:
Master Airscrew 16x8 composite prop 8,480
Xoar 17x8 wood prop 7,780
Master Airscrew 18x6 Classic composite prop 8,130
I did some further tests and got these results using some 18x8 props
Master Airscrew Classic 18x8 prop 7,095
APC 18x8 prop 7,095
Vess 18x8 Sport prop 7,225
Xoar 18x8 prop 7,180
Using Pe Reiver's prop power calculator spreadsheet, with the numbers from the 18x8 props, shows the engine was developing around 2.3 to 2.4 HP and static thrust was about 14 pounds static as well as a calculated airspeed of a little over 53 mph. The 18x8 props keep the peak RPMs under 8,000 rpms by a good margin too. As the instructions state 8,000 rpms is max for the engine.
The engine was fairly easy to get running.When cold, I would use the choke to get it to pop, runand turn over a few times. Then flip the choke off and flip it again, and usually it would fire up and start running. But I would let it warm up before giving it much more than low throllte. After it was running a while, it would fire up and run on one flip of the prop most of the time. The vibration wasn't really all that bad and seemed to be pretty low actually. I had some other engines glow and ignition that could vibrate the stand apart and one of those made it almost impossible to hold the throttle lever at WOT too.
The engine is a little on the heavy side but not all that bad though. On the Gee Bee that may be a plus as I won't have to cram and jam everything forward as far as possible.
The prop washer is loose on the crankshaft end tip. I used some tape to put on the shaft to center the prop washer with. So with a snug fitting prop, you'll have to either put on shrink tubing and shrink it on and then put the prop washer on or make a spacer to fit for it. I think making a new prop washer is a better wayto do it though. I din't really like how they did the three prop mounting screws. As they have the screws pretty far out to the edge of the prop hub. That causes you to drill at least one hole out pretty close to the outer edge of some props. Plus the three holes just don't seem to align well with any props I want to use. But the props I tested didn't break on me, and I was careful to not be in front of the engine where if a prop failed it might hit me. You cannot depend on the center threaded part to hold the prop on either as the hub isn't knurled on the end to grip the prop, and although they knurled the prop washer, that is sort of useless for locking a prop in place. So you have to use the three mounting screws. What I did was fit the prop on, using the prop washer as a guide, center the prop washer and mark the screw hole locations and then drill those out using a drill press.
you can see some corrosion on the screw heads here in this pic
engine by itself weighs this much
Engine with all of its accessories is obviously more heavy
I am not particularly fond of the three bolt prop hub setup. The washer is knurled but the prop hub end isn't. So you pretty much have to drill holes in the props touse the three screws to hold the prop on with.
The muffler is pretty nice looking and well made, but it is quite loud though. You'll need a quieter muffler for some flying areas.
Test running the engine
A tachometer reading using a Master Airscrew 16x8 composite propeller
A tach reading using the Xoar 17x8 wood propeller
A tach reading using the 18x6 Master Aiscrew Classic composite propeller
The engine temperatures were not bad, the engine right at the base of the spark plug on the head was reading around 382 degrees Farenheit after a few minutes at full throttle.
