I don't always do the brightest things, but looking hard at this little beast for a class II carrier build. It's one of there ducted fan engine's. 


Thinking for a Mauler or Guardian.  Not sure if these can really throttle down very well though.

Looks like the specs are somewhere betweeen 2.7 to 3 ish bhp up around 20-22,000 rpm on the ducted fan.  I was looking around trying to find any discussions on guys using these DF engine's with normal props  and found some suggestions of 10X8 & 10x10 props on some RC stuff.... around 20 oz.... 

Yeah I am realizing I will have some choices to make.  TJ mentioned choosing between piped and low nitro versus open and lots of nitro,which it sounds like you are in the open and high nitro camp. Once the little hooligan arrives I may pake a post in the engine set up section once i try and digest the rules and come up with a plan lol. Plus I get the blade tip speed  thing as well so will keep that in mind.

How do you like your 40/46 versions?  How long a life do you see and what problems if any doyou need to keep an eye out for using them for carrier?

In looking at the old Peter Chin evaluation from a magazine in the 80's they show the exh duration of 165 degrees, I can paste the article file if that will help.  I'm not sure where that falls in the open versus pipe or tuned pipe range.

As reported in the NCS HLL newsletter, Terry Heron recently did a high speed of 14.86 (121 MPH) with what I assume to his father's OPS powered Judy. Maybe he built a new one.  I don't know.  Either way, it's a lot of speed for a scale model plane.
Hide behind a van.

Well it showed up and it looks NOS it's never had fuel in it    I, ah am kinda thinking of jumping off the real deep end and seeing if I can fit this with its RV in to a Mottin Skyraider.  That would be insanely cool. 

I know I found some thoughts from Paul on th Mottin Skyraider as he built a really nice one....  You really think it is too reasonably small for a .60 or in this case a .65RV?

Dennis, Years ago I built 2 Skyraiders. One was the .40 size and one was enlarged for a McCoy .60 and ended up with a Fox Eagle .60. That was a good combo and placed at the 73 Nats in the junior class.  As far as available designs, maybe the Mauler.  Pretty sure my pal had the os in a Guardian. It is a big ass motor!   TS

I built two Mottin Skyraiders.
One with an Enya 60RC and one with an OS Max FX 25.

The successful prototype by the designer used an ST 40.  I came to believe that idea of a 60 was a bad dream.  I followed that dream and did not last long.
But my 25-powered model has lasted almost 20 years.
If I was to build a model for your engine I would get all the wing area I could get within the 44" wingspan.

The middle pitcher is a Hobo Sandy that I pho-grapped at NKP.  The Hobos would arm-up their 12 weapons next to us before takeoff.  This is then root cause of mem favoring the design.

Package three.

I made it so I could cut into it to fix the tank and bellcrank. But thus far I have never needed to.
I only took off the cowling once, when I repainted the model.

This plane will not beat a full race 40, but it got a lot of prizes when the full race 40's crapped out on low speed.

I like side mounted whenever possible.  That way, either upside down or upside right, the engine never hits the ground, deck, or pavement.

In addition, with side mounting, the engine adds to the tip weight.

Finally, inverted mounting can cause a hydraulic lock when starting and upright allows the engine to flood via overflow from the spray bar.  Side mounting cures both of these issues.

I like side mounted whenever possible.  That way, either upside down or upside right, the engine never hits the ground, deck, or pavement.

In addition, with side mounting, the engine adds to the tip weight.

Finally, inverted mounting can cause a hydraulic lock when starting and upright allows the engine to flood via overflow from the spray bar.  Side mounting cures both of these issues.

I wondered if to the side would help tip weight when I started thinking about it.
The other problems for up and down make sense.

Even turing it sideways would still help some with center of mass and not putting a big bobweight three inches above the wing, not that it matters a great deal...  More just thinking or over thinking stuff.

Bill, am I right in thinking since my enigne is the later version I can'e set it up for reverse rotation?  What performance benefit would I be losing runing it normal rotation?  Sorry a rookie question.

If you are going to fly Nostalgia Carrier, and not try to prop hang, the reverse rotation isn't nearly as important. However, if you can find the disc valve parts, they are a bolt in replacement. "Back in the day" when ducted fans were the only choice for flying jet models, I was able to trade "new style" parts to a ducted fan guy for his "old style" parts. You may also find a CL speed guy with some old parts. It is probably also possible to make a new notch for the crankpin in your engine's drum rotor to reverse the intake direction. If you don't fully understand what this means, you should find someone who does to help you.

If you are going to go for "modern" slow flight, the torque from a reverse rotation engine will be a significant asset in keeping the plane out at the end of the lines during slow flight, or any time you "goose" the throttle.

Whatever route you choose, heavy, loud, fast class II models are a rush to fly!

If you are going to fly Nostalgia Carrier, and not try to prop hang, the reverse rotation isn't nearly as important. However, if you can find the disc valve parts, they are a bolt in replacement. "Back in the day" when ducted fans were the only choice for flying jet models, I was able to trade "new style" parts to a ducted fan guy for his "old style" parts. You may also find a CL speed guy with some old parts. It is probably also possible to make a new notch for the crankpin in your engine's drum rotor to reverse the intake direction. If you don't fully understand what this means, you should find someone who does to help you.

If you are going to go for "modern" slow flight, the torque from a reverse rotation engine will be a significant asset in keeping the plane out at the end of the lines during slow flight, or any time you "goose" the throttle.

Whatever route you choose, heavy, loud, fast class II models are a rush to fly!

Thanks Bill, My general interest is probably more in the nostalgia so not really planning on hanging it.

As far as the reverse rotation, I'm assuming for the disc one your just flipping the disc over like flipping a plate so the drive pin hole is on the other side of the opening for reverse rotation.  Think my ST .65 is like that although that enigne is pretty beat up maybe just a core, never really looked at it too deeply.
Also assuming on the drum you can't physically just flip it over in the same way so in order to get the same effect of moving the drive pin point you would need to add the notch you mentioned.  I'll pull the back cover off and see what that drum looks like and see how feasable that looks.  If I went that way, I might be able to set up a jig on my lathe toolpost so I could clock it correctly. BTW, the box on this one is stamped 1989, so I assume it is definitely the later drum style?...

If that .65VR-DF isn't quite powerful enough for a sport/nostalgia model, I came across a .91VR-DF recently. It's missing a drive hub, Woodruff key, and the 9A carb but the rest looks like it would run long enough to tear you out of your shoes....   I kinda think the .65 would have the horses to do the same?  My thought would be to upgrade everything: lines, bellcrank, controls, and put a safety cable around the case and tied to the 'crank mount. And make sure that van that Paul talked about hiding behind has interior panels, too.

After I was given a box full of parts that allegedly was an OS .91VF, I looked around on-line for a parts list. Of course, you get sucked into looking at videos....  There are a few of those that show pretty insane speeds and flying. I wouldn't want to be anywhere on that field near one of these (on a speed plane). You'd likely need a carbon prop, or at least glass, just to keep it in one piece. Even for a .65 you might need anchor chain to fly on? Respect.....

Dave,
You aren't wrong!!
I wasn't kidding early on when I said I might need the speed pole to hang on too lol

MM Good point on the hardness.  We are a ways from that though.

That's interesting. Any reversable drum rotor or rear disk valve I've ever seen has two slots 180 degrees from each other. You did mention turning the back plate, maybe that's the difference?