.19-.25 cu. in. engines in .35 size planes?

[frank mccune]

            Hello All:

            While going through my junk engine drawers and plane kits, I questioned the wisdom of installing smaller, lighter, engines planes that normally are powered by .35 sized engines.  For example, Fox .25. ST G 20/.23 Brodak .25 and Veco .19 engines.  I have a problem with the idea of adding tail weight when this problem may be alleviated by installing a lighter engine making for a better flying plane.  I am thinking about the Sterling F-51. Yak 9 and the Ringmaster sized planes.  I was also considering a 1948 McCoy .19 engine in one of these planes for OTS.  I have not tested this engine for power yet, but it may have enough grunt to drag a small Sterling plane through the OTS pattern.  For some abhorrent reason, I think that an OTS plane should be motivated by an engine of that period.

         Some of the engines mentioned above, have if not the same, very close to the power of the old reliable standards, McCoy .35 and the Fox .35 Stunt.  These two engines have more than enough power to fly the OTS pattern with the above mentioned airplanes. 

         Suggestions/comments?

                                                                                                                                          All of the best,

                                                                                                                                          Frank McCune

[Ted Fancher]

Hi Frank,

I think there is more "there" than you are anticipating.  Back in the WAM (Western Associated Modelers) hey day in the '60s, '70s and early '80s we flew classes of stunt: 1/2A, A and BC Beginner, Advanced and Expert classes as well!

By far the best Class A ships we ultimately flew were the classic sized .35 ships such as Sig Banshees and Twisters, Goldberg Shoestrings, etc. and up to and including very competitive "pro" stunters such as Noblers using almost exclusively the Veco .19BB engine spinning ~four pitch props just shy of peak two stroke (we weren't smart enough to translate that "recipe" to the hot shot "Pro Stunters" until years later.

Running high rev, low pitch operations we were getting more oomph out of those little Vecos two strokin' than we were with the then big deal Fox and OS .35s that were "the" 4-2-4 engines in the pro stunt game back then.  Dave Fitz's dad Bill had a great combination of the Veco in an Aldrich designed kit whose name I don't recall immediately...old timer's taken its toll...that was one of the best flying airplanes of that era I had seen regardless of what was in the nose.  Somebody will remember.  It was a flapped constant chord wing, bubble canopy'd ship right around 500 square inches.

The little Vecos were probably a bit more powerful than the now ubiquitous BB tuned .19s but not all that much.  If you've got a Veco .19BB in good condition in your arsenal that would be my suggestion for your first foray into this interesting segment of the game...just because I'm familiar with their capabilities.  Brett might see this and have a more up to date assessment of the potential for the more modern engines in that range.

Go for it!   You'll have a good time.

Ted

Just checked out my "airplane" pix album and found a picture of my "fleet" at the 1967 Nats.  It included my version of Bill Fitz's ship mentioned above.  It was an Aldrich designed Jetco Dolphin.  Mine had a small case Johnson .35 in it and was grossly overpowered...a small case "s" would have been a better match in that pre .19BB era!  Bill with the 19BB was a harbinger of the tuned pipe era we weren't smart enough to take advantage of for a decade or more.

[Dan McEntee]

Hi Frank,


Running high rev, low pitch operations we were getting more oomph out of those little Vecos two strokin' than we were with the then big deal Fox and OS .35s that were "the" engines in the pro stunt game back then.  Dave Fitz's dad Bill had a great combination of the Veco in an Aldrich designed kit whose name I don't recall immediately...old timer's taken its toll...that was one of the best flying airplanes of that era I had seen regardless of what was in the nose.  Somebody will remember.  It was a flapped constant chord wing, bubble canopy'd ship right around 500 square inches.


Go for it!   You'll have a good time.

Ted

     Peacemaker, maybe? I think everything Aldrich designed that was kitted was by TopFlite, wasn't it? I think it would be the one you are thinking about.
     Type at you later,
  Dan McEntee

[Dennis Toth]

Ted,
I agree with the Veco 19BB, I saw the engine review on it and it likes rpm. Here is the website that has the enginer review (http://sceptreflight.net/Model%20Engine%20Tests/Veco%2019BB%20CL.html), if you go to the index they have tons of engine reviews. The torque curve peaks at around 11,500 just about prefect for the four pitch. It also likes nitro. This is about the same as the K&B Torp 19 that was very strong in the old Class A speed.


What diameter prop did you guys use? Seems a good standard width 10x4 would work well.

Best,    DennisT

[Larry Fernandez]

The Jetco Dolphin was designed by Lew McFarland.

Larry, Buttafucco Stunt Team

[Larry Fernandez]

What diameter prop did you guys use? Seems a good standard width 10x4 would work well.

Best,    DennisT
[/quote]

I would start with an APC 9-4

Larry, Buttafucco Stunt Team

[Gary Dowler]

I was happily flying my Shoestring Stunter , typically fitted with a Fox 35, with a OS 20FP. Flew beautifully until a freak accident destroyed it.
That motor then went on a hand me down Cosmic Wind, and it works just as well there.
Brett insists that a lightly built Ringmaster will do well with a 15FP, and I think I believe him.   Some small engines are just powerhouses!

Gary

[Brett Buck]

  For example, Fox .25. ST G 20/.23 Brodak .25 and Veco .19 engines.  I have a problem with the idea of adding tail weight when this problem may be alleviated by installing a lighter engine making for a better flying plane.  I am thinking about the Sterling F-51. Yak 9 and the Ringmaster sized planes.

     Of those, the Veco 19 (presumably ball-bearing version) will provide *much better* performance than a Fox/McCoy 35s on these small airplanes. That's because you can use a 4" pitch prop instead of a 6" pitch prop. For the Veco 19BB, try an APC 9-4 first, and then an APC 10-4.

   While it is not the match in terms of run quality and down a little on power from a 20FP, it runs OK on a 10-4, which permits you to get a little better.  The problem for the Ringmaster/Yak will be having it fly too fast, i.e. too much power,  rather than not enough. Uncle Jimby started with his Ringmaster (the RSM cover art model, 20 points at VSC) and a Veco 19BB and APC 9-4, and a 9-4 APC. .015x60 lines, set to run properly in a two-stroke, it went 4.2 seconds a lap. He switched to a 10-4, and it went 4.1. We switched to a 20FP/9-4 APC and it went 3.8!

      The other engines will fly the airplane, but not with the sort of huge performance jump you get with a Veco 19BB. For this sized airplane, a 15FP is likely to be better - but you don't seem to have one.

    You might want to consider getting Jim Lee or Randy to make you a venturi about .010 smaller than stock, since you will likely be wanting to slow it down, and also to improve the fuel draw, which unlike the 20FP, is marginal.

   The stock Veco 19bb will (as Ted notes) fly *much larger* airplanes than the Ringmaster perfectly well.

     Brett

     

     

[Brett Buck]

Just checked out my "airplane" pix album and found a picture of my "fleet" at the 1967 Nats.  It included my version of Bill Fitz's ship mentioned above.  It was an Aldrich designed Jetco Dolphin. 

  I think that was Lew McFarland (the box art airplane used to hang on the wall in his shop in Lexington). It's a blown-up Shark 15, with a full fuselage, and styling that looks suspiciously like a Peacemaker, although its bigger.

   The 20FP is substantially more powerful than the Veco 19BB, but you can make up some of it because the Veco doesn't fall off as much with 10" props. The 20FP runs much, much steadier, at least the examples I have seen. Either one is great overkill power on a Ringmaster  - you may or may not recall that David and I borrowed your Ringmaster/Veco 19BB at the NWR one year. We didn't know what prop to use, so we got a Master Airscrew 10-5. It flew at about 3.0-3.1 second laps, and I was pretty convinced the wings were going to come off, because it was pulling about 3" of dihedral in round loops. We switched to a 10-4, that was still far too fast for success, but at least I could see the airplane the entire flight. In one of David's flights, up you walk (having flown for free to the airport and still in your uniform) to see David almost crashing yet another of your Ringmasters.

     The Veco might be a better choice for the Ringmaster than the 20FP, if only because it *is* a little weaker, and thus slightly slower (albeit still really fast). The best-flying Ringmaster I have ever flown was powered with a *15FP* and a 9-5 prop, this was no featherweight, it was built from the kit wood and had a full opaque dope finish. 15FP, no problem, and not so insanely fast.

    Brett

[Dennis Toth]

For the Veco 19BB I think you want to get the rpm set around 10,500 on the ground which should bring it up to 11K ish in the air. With the 10x4 prop if it is going to fast you can do a couple simple things to trim the speed. First, add a few feet to the line length. You trim about 0.1 sec per foot of length. Many of the Old Timers flew on 65' lines cause they wanted the ship to fly fast but needed the length to keep up with it. Second, you could just de-pitch to 3.75 - 3.85" pitch. You could try a few different brands of prop - the APC, Brodak BYO and the RMS props are pitched as marked. The Rev-ups are a little less then marked. All can be heat pitch if you have a pitch gauge.

Last, you could drop the nitro to 5%.


Best,   DennisT

[Brett Buck]

Last, you could drop the nitro to 5%.

  Repitching the prop is the best solution, and that's what Jim ended up with to tame his Ringmster/20FP.

   I don't think you want to run 5% - it's already pretty unsteady-running on 10%, more nitro would smooth it out a bit.

    Brett

[Ted Fancher]

The Jetco Dolphin was designed by Lew McFarland.

Larry, Buttafucco Stunt Team

To Larry and the half dozen others who took me to task for attributing the Dolphin to George...you all are, of course, 100% correct.  The Dolphin was a Lew McFarland design and what's even more embarrassing is that the old Nats picture I referenced of my Dolphin in the pits was taken primarily because Lew's Shark and his back-up Dolphin were sitting in the pits right in front of my "Pirouette" and Dolphin.  the whole reason I took the picture was to have a picture of Lew's fleet and mine side by side at a "Nats"!

Just hate this "old-timer's memory" schtick!

Ted

[Larry Fernandez]

To Larry and the half dozen others who took me to task for attributing the Dolphin to George...you all are, of course, 100% correct.  The Dolphin was a Lew McFarland design and what's even more embarrassing is that the old Nats picture I referenced of my Dolphin in the pits was taken primarily because Lew's Shark and his back-up Dolphin were sitting in the pits right in front of my "Pirouette" and Dolphin.  the whole reason I took the picture was to have a picture of Lew's fleet and mine side by side at a "Nats"!

Just hate this "old-timer's memory" schtick!

Ted

No need to be embarrassed Ted, the world knowns that you are my “Stunt Hero” (You Brett and Dave)
My first full up stunt plane was a Jetco Dolphin my dad built for me using one of his Fox .35s
After I joined the Navy I built two more. They are are straight forward and easy to build.And they look so graceful in the air.
When my son, Aaron won beginning and Junior at the Golden State Meet, he started building a Dolphin, but he did not have the patience to finish the plane and it was given away to one of our club members.
I have a bunch of FP .20 s , and I am considering building a Dolphin for one of these motors

Larry, Buttafucco Stunt Team

M

[Ted Fancher]

After looking a bit closer at that picture from the 1967 Nats I noted a couple of other airplanes of consequence.

Just forward of Lew's two ships is Bart Klapinski's Walker Cup winner that year (I'm sure Larry will remember the name of the airplane) and just forward of that are two of the original Sig Chipmunks including designer Mike Stott's.

[Dennis Toth]

MM,
Is your Veco 19 the original plain bushings series 100 engine or the Series 200 ball bearing version? I think the one we are talking about is the series 200. If you look at the torque curve for the two versions the Series 200 has a much flatter curve from 10K to 12K. This is very similar to the K&B Torp 19, but better with the ball bearings. (http://sceptreflight.net/Model%20Engine%20Tests/Index.html). I like the Veco over the FP because you can use the 10" diameter prop and still hold rpm and drive. I don't think wear would be a problem if you have at least 25% oil and have reasonable cooling.


Best,   DennisT

[Phil Spillman]

Hi Frank, Check out the current issue of MA to see Keith Marks' Squaw as powered by an ST.23! Keith says it flies like a dream! As for me and my experience, in about 1993 or 4 Gil Reedy and I built or resurrected Sterling P-51F's and put either FP .25's or LA .25's on them and had so much fun flying follow the leader and doing consecutive loops and eights together in the circle! Those old birds never flew so well back in the old days as they did with the .25's up front! Bret Buck raves about the FP .20 on many of his old birds and says that a Ringmaster S1 powered by his FP .20 is a competitive PA ship! I've tried this set up using a stock muffler and it works!

Brodak's FlyIn now has a Ringmaster Day where hereto for everybody flew on the same circle using the same set up! I believe that B-.25's, LA .25's and FP.25's are all acceptable perhaps others too, for power. you should see Joe Gilbert fly his Ringmaster at the FlyIn! All classes fly together with no concessions granted as per skill classes in the past. I hope this policy is amended this year BUT even if it isn't I can absolutely say this event is great fun and most of us don't give a pig's pitutty about who wins or who scores what! This old bird never flew so well with a Fox period!

Phil Spillman

[Larry Fernandez]

After looking a bit closer at that picture from the 1967 Nats I noted a couple of other airplanes of consequence.

Just forward of Lew's two ships is Bart Klapinski's Walker Cup winner that year (I'm sure Larry will remember the name of the airplane) and just forward of that are two of the original Sig Chipmunks including designer Mike Stott's.

I believe it to be Bart’s Tempest.

Larry, Buttafucco Stunt Team

[Ted Fancher]

I believe it to be Bart’s Tempest.

Larry, Buttafucco Stunt Team

Yup!  that's it.  I believe it is true to state that Bart's victory at that Nats was the first and only time a stunt pilot did so on the occasion of his first Nats entry.  If I recall correctly Bob Gieseke was second and Dick Mathis (Chizler) third.

Ted

[Air Ministry .]

Re: .19-.25 cu. in. engines in .35 size planes?

EASIEST WAY is to use TWO OF THEM .  ( Wings are 48 in x 8 in ' core ' .

The Mosuito , when aged VcV Jeffersons Axe was timed at 88 mph at a speed meet . Not that they mentioned what it was . On 20 % Nitro I fink .
Gottum some Rossi R 5 Plugs forem , Sound mean nasty and meanacing with those , so we may top 90 . If I build another on , as I gae it away in a moment of weakness . Sorta hair trigger - Honda ( Er AJS STORMER !  ) M X Vs H D  big thingo . V precise . good Combat Id Think .

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Bob Barons early twin boom thing was Veco 19 on 10 x 4 , bladder & stuff . I mabe recall ? 

[Brett Buck]

I like the Veco over the FP because you can use the 10" diameter prop and still hold rpm and drive. I don't think wear would be a problem if you have at least 25% oil and have reasonable cooling.

    You could get more power and the same RPM, and better drive, with a 20FP and a 10-10.5" prop, if you deviate from the plan (i.e. *stock*) and use a smaller venturi and depitch it. I tried that early on, it easily worked that way, but involved things that I rejected because it required modifications. I have run the 11-4 and 11-3 APC on it (actually the very same prop David ran for a while on his PA40) and it would fly the airplane and didn't melt.

    But the key to the performance improvement on the 20FP is *getting it unloaded*, and using the loss of efficiency to your advantage. It's also the key to keeping the airplane out of the transonic region, the very last thing you want on a Ringmaster with a 20FP is a more efficient prop. You don't have quite as much overkill power with the 19, so you can tolerate larger props. But the 19 still *way more* than required and if you wanted to get it up to 100 mph, you probably could. Don't try maneuvering at that speed, or if you do, please videotape it!

    Most of the Veco 19s used this way very quickly ended up with cylinder baffles to try to keep it cool. David's has that, and last I recall Ted's was the same way. David's engine is approaching (or long since passed) EOL, it's all over the place. A not-worn-out example is pretty OK as long as you keep it cool and, as you say, run it on lots of oil. The FP can be thrashed pretty hard with no long-term effects. I have seen people run Tornado 10-4's 3-blades  on them, and while that is clearly not the way to go, it ran OK and was still alive when they gave up and put on a 9-4 APC.

     Brett

[Brett Buck]

The Dolphin was a Lew McFarland design and what's even more embarrassing is that the old Nats picture I referenced of my Dolphin in the pits was taken primarily because Lew's Shark and his back-up Dolphin were sitting in the pits right in front of my "Pirouette" and Dolphin.  the whole reason I took the picture was to have a picture of Lew's fleet and mine side by side at a "Nats"!

  Wow, those were the days - everybody took their backup airplanes to the field with them?

     Brett

[Air Ministry .]

If the planes real light , you can hold it nose vertical & its got more thrust than weight , itll go up .

You can likely use lighter lines , and maybe shorten them a bit , say 55 ft. instead of 60 , as they
are a fair part of the equation . the Gorrie Mi-T 10 x 4 props are good on the Foxes & Vecos ,
might take a picture while ive gottem dug out . Theyre Obsolette unobtainium tho .
The 1964 12 x 4s lower A / R but Undercambered ! .

[Larry Renger]

I have a FP 20 on a fairly light Ringmaster on 60’ lines. It is too fast, and eats too much fuel (close but no cigar, need about 10:more laps). The trim is great, so I don’t want to change engines.

What diameter venturi, or what percent reduction of passage areia should I aim for?

[Brett Buck]

I have a FP 20 on a fairly light Ringmaster on 60’ lines. It is too fast, and eats too much fuel (close but no cigar, need about 10:more laps). The trim is great, so I don’t want to change engines.

What diameter venturi, or what percent reduction of passage areia should I aim for?

     With the stock spraybar, try .245.

    How much fuel do you think you are using?  All of mine use about 2 - 2.25 ounces for a full PAMPA pattern.

     Brett