1967brutus

They were in general, GREAT engines: When they were still around, national Dutch championship 1/8th scale offroad buggy was won twice in a row with a GO engine.
I still have one (Rotorstar Apache branded) brandnew in box including the original cooling fan and the original Vortex heli muffler additional to the one I have been flying the past 7 years (identical set-up WRT fan and muffler).
I did however change the heatsink-eads for those of the MK II which are better in every respect.

1967brutus

It has all appearance that this engine was not even fully broken in (I have very little info on how much it has been run previously) but after several months of being shelved, I ran it for several hours in the past 2 weeks, now with the solenoid mixture control applied and first of all, fuel consumption has dropped VERY significantly (by about a factor 5, no joke) but what is more, over the course of that runtime, it gained about 850 RPM with the 9 x 5 (13850 RPM, appr 0,56 hp) and it does 12550 on the 9 x 6, or about 0,5 hp.

A plane build specifically for this engine is underway, but it most likely won't fly before spring next year.

I was highly surprised to see the engine gradually gain power, and it appears it has more of whatever it is people call "compression" in a Wankel.

But I have to do something about the muffler, because it is pretty restrictive. This engine responds apparently to inertia in the exhaust ducting. Simply extending the stock muffler with a random piece of silicone tbing resulted in a 300 RPM gain, repeatably.

1967brutus

Proudly presenting the M1200:

Raleighcopter

I happen to have a nx4 with the gaui t10 engine. I should fly it some time.

1967brutus

you should....

The engine itself, absolutely is mechanically sound. The carburation is the issue. So far, I have not yet been able to figure out a solution for that other than to supress the issue by altering the shape of the LS needle a bit, and to supress the issues with the use of a governor.
But mine has provided 7 years of reliable and very frequent service, until I crashed the heli due to a broken lanyard causing the transmittertray to drop from under my hands...

I hate it when that happens...

1967brutus

This is about "modifying engines" but has little to do with "modifying to gasoline".

The Wankel is being used in pusher configuration, however, there is no pusher muffler availlable and the stock muffler cannot be reversed. That is to say, it can be, but will protrde into the prop arc.

So despite these parts nowadays basically being "unobtanium", it was of little use to me as is: it would still cover part of the plane with oil during startup and warm up, and I decided to bring out the hacksaw, basically (actually, I used my Dremel motorized Jigsaw, but that's just minor details )

I cut off the dome of the muffler body, and chambered the now open end on a lathe to accept the tailcap. Then since there is not much flesh left to machine the domw, I flattened the edges as good as possible and used Belzona 1111 to seal things up on that end.

Pretty sure I am now not only the only person with an OS Wankel running on gasoline, I probably also am the only person with a Wankel having a "Stock OS pusher pipe"

ductedfan

Good Morning all. I enjoyed reading all of the posts. I do have a couple of questions.
1. Do you guys have a procedure that you follow to convert these glow engines to gas? I have two .90 Rossi engines that I am thinking of converting. I will post pictures of them as soon as I can find them in all of my stuff. But, when I bought them, I was told by the seller that they were ducted fan engines. They look vastly different than the 'normal' Rossi .90 engines. They are much larger than the .81 Rossi that I have.
2. Along those same lines, how much of an RPM drop comes with the conversion? The reason I ask is because there is an article for an F-4 fun scale phantom that has a diesel engine (OS .77 with a Davis Diesel head) in it and somehow achieves enough RPM to power it!!!
So, what are your thoughts??? Thanks in advance for the info.

Cheers...

1967brutus

I would not go for a gasoline conversion if the goal is IC ducted fan...

The issue is not so much with heat or lubrication, much more with most likely the ignition not being able to keep up with that kind of RPM, and the short life of the plugs IF it would be able to...