What is a good ignition stunt engine?

I am interested in getting an ignition engine to use in oldtime stunt. I have never had an ignition engine. What are some good ones to acquire? Is there a particular engine that has the best running characteristics for stunt? Is there a good stunt running engine that is also easy to deal with, in terms of the ignition system? I was thinking in the .40 to .60 size range, though I am open to reasoned suggestions. This inquiring mind would like to know. Thanks, in advance for any advice.
Nick Vanmatre

The all-around best I've seen to date are the OK Super .60, the Anderson Spitfire and the Super Cyclone. My OK .60 has had a few problems in over 300 flights, but overall, I'm really pleased with it.
I wrote a very comprehensive article on spark for Stunt News a few years back - it may be avalable through the archives.
Bob Z.

The Super Cyclone .60 is an excellent engine for Igntion stunt. It is light, easy to start and run, and is pretty reasonable to buy. Be sure and check the main bearing for wear before you buy one. They were a very common Ignition engine.

The Anderson Spitfire is an improved Super Cyke. It is both heavier and more expensive than the Super Cyke.

Isn't the question an oxymoron?

See Ya

>Isn't the question an oxymoron?
>

No, not at all. Some of the old ignition motors have darn near ideal characterstics for traditional stunt motors, and with electronic ignition and good batteries, the weight penalty is not prohibitive. The only reason that I didn't try it back in the 80's, when stunt motors were an endangered species, was the noise.

Noise is a problem...unless you live in Tucson. Here in Sandy Eggo, we are struggling to keep a field, much less one that would allow an unmuffled large engine.

As I have aged, my hearing has diminished a lot, so noise is really not a problem to me...personally.

I wish there were a muffled oldtime ignition engine suitable for stunt... Of course, if wishes were dreams, all men would --

Nick V

Hey, P-man - bad call. You've heard mine and Doug's run.
Brett - good call. With the modern batteries (I use NiMH) and some modifications I've made to the coils, the reliability is excellent. I've found that I don't even need the transistorized ignition. In the many years I've campaigned the Viking/OK .60, I've never had a non-start at a contest. All with points triggered coil.
And, good point also about noise. I've not yet seen a muffled spark engine. However, I'm working on a modification to the OK now that will (hopefully) allow the use of a muffler. Heat is the big problem - worse for me as I run mine only on gasoline/castor.
Bob Z.

>Hey, P-man - bad call. You've heard mine and Doug's run.
>Brett - good call. With the modern batteries (I use NiMH)
>and some modifications I've made to the coils, the
>reliability is excellent. I've found that I don't even need
>the transistorized ignition. In the many years I've
>campaigned the Viking/OK .60, I've never had a non-start at
>a contest. All with points triggered coil.
>And, good point also about noise. I've not yet seen a
>muffled spark engine. However, I'm working on a modification
>to the OK now that will (hopefully) allow the use of a
>muffler. Heat is the big problem - worse for me as I run
>mine only on gasoline/castor.

Right - Big Art offered to make me a muffler for a proposed Orwick-powered model, but I never really got past the idea stage. I have to wonder how well that would work on the old sub-piston induction motors.

The heat is impressive on gasoline-based mixtures. But I think it would probably be preferable just based on the specific energy contest being so much higher. Plus, it's really cheap.

They used to make a muffler for sparkies (Don Hutchinson had a picture of such a thing, I think) that was about 18" long. One wonders about the potential for tuning effects, but it was a non-starter as it was heavy aluminum. And there's no way in the world you could consider a graphite-epoxy muffler - they barely stand glow motor temps, no way in Hades they stand up to sparkie temps.

When the ST46 and 60 were discontinued, it looked like a much more practical idea. Any more, it's sort of a dead idea for serious stunt, since there are so many more competitive motors.

But it certainly could be made to work. I bet an Orwick 64 or Anderson on gas and spark is more than a match for a stunt-tuned ST60 at 9000 rpm.

Having never given the idea serious consideration, I could be way off base here, but aren't there tuners serving the FF and RC Assist Old Timer guys offering modern engines which have been converted to spark ignition?

Seems like a much better option than basing one's efforts on an old clunk that might be put to better use in a collection.

No Dan, I did that once back in about1993. A Magnum 40 GP that ran like a Swiss watch. After winning the spark ignition event at VSC two years in a row, they made a rule change making glow engine conversions illegal. I replaced the Magnum with a Torp 32 and won it once again. It wasn't the engine, it's knowing how to make a spark system work well.

The man that makes the Super Cykes told me that they will turn a
APC 12x6 right at 13k with sub-induction, 300rpm less with out.

Thanks for the engine recommendations, and the suggestion to check with the SAM ignition folks. The FFs and oldtime RC assist tune for max RPMs and short motor runs, as opposed to longer run with varying flight loads... Still, I will check with them for engine recommendations. I appreciate the info and hope that more will come in.
Nick Vanmatre

Ed Shillen, makes Torpedo .29 & .32 replica's, Walter Huhn makes a
reaaalllly nice Super Cyke .60 or .65 one. There is a Anderson Spitefire
made by Marvin Miller that is just beautiful.

Walter:+

How about the Atwood Super Champ, also a reasonably priced ignition motor, but if you can afford one why not an Orwick. They have taper in the sleeves while many of the contemporary motors of the time only had parallel bores. The Orwicks were from what I understand were the engine to have had in the day.

Brett I didn't think that if the sub induction was case ported and totally separated from the exhaust port as per the Orwicks would have any effect on the addition of a muffler. I was under the impression it's only if the sub induction is achieved by opening the crankcase via the exhaust port under the piston skirt that you may get problems when adding a muffler. Did you actually get a muffler made for your Orwick? it's something I would also like to pursue.

Regards John

While its true that Free Flight uses short high speed engine runs I don't know of any of the replica manufacturers that re-tune the engine/design for better performance in that mode. SAM approves each engine allowed on an individual basis and would be likely to disapprove any that showed any substantial performance improvement over an original.

The Super Cyclone is a great engine but remember that there are G and GR models as well as a .60 and a .65. The G model does not use sub-induction while the GR does. They are identified by the letters stamped inside the case rear cover. I don't know if the replicas are the same but I would think they have to be.

The OK Super .60 is also a good choice. Its a strong runner (relatively) and easy to handle. Plentiful too.

Remember that 99% of the problems experienced with sparkers are ignition system related. I've seen systems with twisted together wire connections, battery boxes that were so loose the batteries fell out, point gaps way to big or non-existant, no grounds, oil in points, and on and on. A good system will improve starting and running qualities tremendously. Sparkies CAN be fun!

MECOA in Los Angeles makes a new spark or glow replica of the Cunningham 0.647

They describe it as a modified Orwick.

It is a beautifully finished piece.

I THOUGHT that "Dr. Spark"? used one with his transistor ignition in a Yates' Dragon that was featured in his article for the AMA magazine last year...do not remember what issue.

I may have the user and model wrong, but there was an AMA article on an old time stunt ignition model in the last year. Help me out here.

MECOA has built more than a few vintage sparkers, Forster 99's, 29's/35's, etc, but the runs are short and the demand is not large so I guess it is hard to rationalize producing engines that won't sell 20 a year, even if you own the tooling. Labor of love.

A new replica may make more sense than an old original, especially if you want to fly, not collect dust.

Isn't the Madewell 49 Jim Lee used to win OTS at the Nats a sparker?

George Aldrich told me he had run an experiment on subpiston induction and mufflers. He ran an engine with muffler (sorry, don't remember which engine) then cut the bottom of the piston to give subpiston induction. He saw no change in RPM or handling characteristics. Just repeating what he told me.

Fellows. Regards to sub-piston induction. I went round and round with a fellow in Australia about this. So I taped the four 1/8" holes in my Orwick 64 and ran it with and without sub-piston induction. The difference was so slight that normal tach error could have been the factor. Actually, with 12" or 13" props and under 10K RPM, the sub-piston effect simply doesn't do much. My RJL Cunningham Blue Streak has only two 1/8" holes, in contrast to the 4 holes in the Orwick, Super Cyke and Anderson Spitfire. For our use, it makes little or no difference.

Floyd,

I think the difference may be more evident in an engine that inducts under the pistion in the exhaust stack with a muffler being used. The induction holes in the Cyke, etc would still be open with a muffler on the engine. Not that is makes a tremendous difference I suppose, but there will always be the mystery engines that balk.

Floyd,
How do you like the RJL Bluesreak? I checked the MECOA website and it "looks" nice... But how does it run? Doing stunt service?
Nick Vanmatre

Randy. I recommend the RJL Cunningham Blue Streak 65 engine. They are well made, although ugly! Mine had way too much compression ratio, and I had to mill out the cylinder head to make it easier to start. The original Orwick engines had about 12:1 CR and many owners had trouble with that. The replica K&M Orwick engines had less CR and they run with no problems. I also had a Dunham (England) Orwick 64 replica which was just about right. Unfortunately, the metallurgy was not quite correct, and it suffered premature wear-out. I hope that someone will again build Orwicks with modern metals. We shall see.

>Isn't the Madewell 49 Jim Lee used to win OTS at the Nats a
>sparker?

I have flown a Madewell 49 and can recommend it highly. Runs like a small Anderson. The Madewells are reasonably priced and fairly common, although SAM flyers are starting to appreciate their potential.
A 10x8/ 11x6 prop and 3:1 gas/oil would be a good start.

regards

David. The Madewell 49 is indeed "made well" . These motors ran like crazy on glo, which is where most of them ended up. If you find one in good condition and you run it on spark ignition, you will be well served. The companion Vivel 35, made by Earl Vivel in San Francisco is also a good engine, but not many were made.

David,
Your Madewell looks really nice. I am going to look for one; hope to get a nice one. Now what real oldtime plane would be good to matchup with the Madewell?
Nick V

The Yates Dragon. The plans that PAMPA sells are drawn with a Madewell 49 shown. If you choose to run on a glow fuel such as Fox Superfuel, you will have to redo the front end a bit to fit in a larger tank. Superfuel runs good on spark and is good for the old engines. I find it fouls plugs less than a gas/oil mix plus if the spark system fails, you can put in a glow plug and still fly!

>David,
>Your Madewell looks really nice. I am going to look for
>one; hope to get a nice one. >Nick V

Nick,
The Madewell is a good choice, but I recommend you have someone do the following modifications to ensure the best performance. This is not essential, but will turn a good engine into an excellent one.

1) check the squareness of the cyl to shaft axes. This is done by mounting the case on a mandrel through the bush and skimming the rear face. Then the case is mounted on an angle plate and the cyl seat is skimmed. Very little material should need to be removed and the reduction in lengths will have no detrimental effect.
2) check the conrod eyes for alignment and bend as necessary.
3) lightly break the edges with a stone around the inlet port in the shaft.
4) tighten evenly and use loctite on the two 6.32 cyl screws
5) if the needle valve assy is at all dodgy, replace it with a modern type.
6) the thin mounting lugs on the Madewell are not usually flat. Rather than machine them, mount the engine with epoxy under the lugs to square it all up. Don't forget to use some sort of release agent on the lugs.

So buy the best Madewell you can find and send it to someone like Don Blackburn for the work outlined above. Alternately I'll do it for you for the cost of postage to Australia and back.

good luck with your first OT ignition model