Wen-Mac Beachcraft Bonanza

The glow plug glows.  It has two gaskets, so it may not be a Wen-Mac plug.

My igniter drycell substitute of five D cells soldered in parallel measured over 1.5V, even though it is ten years old. I sandpapered the connector and hooked it up, and I got a puff of smoke and a bright orange glow. I rinsed it with acetone, but it was already pretty clean.
I read that old fuel is hard on glow plugs, but my local Hobby Town has it.

That looks like a great place to fly control line, flat and protected from the wind.  Looks like a nice model on the cart too.

I do think I have a place to run the engine.

This thing is pretty, in spite of the oil stains. That is my favorite light aircraft prototype, largely because it was one of the first Strombecker non=flying hard wood models that I built when I was a small child. I don't think there were any plastic models yet at that time.

Hi David,
Pretty neat project!
Its a Wen-Mac plug, if you look close i think it stamped on plug, but who knows how it ended up with two gaskets?
Lol, odds are it's a really low time engine as most planes lasted only seconds. The Wen-Macs of that time had a groove around the inside cylinder that really shortened life, the groove was to help manufacturing not long life. Most plastics RTF's came on to the market in the early 50's, the Bonanza about 1956.

I'd keep lines to 20-25' max and fly over grass, a roll of carpet or large cardboard makes a great runway, if you need to buy fuel, high nitro with lots of oil.

Have fun!

It is amazing how "toy" has been re-defined.  In the 50s and still in the 70s these were clearly children's toys that could be played with in the street in front of the house, or in the nearest park.  Now, I am thinking of going on top of a mountain to fly it, or over the mountains.  I flew a 25 gram EPP RTF RC in a nearby park, and convinced the keepers not to invoke the law on me, but I feel I have to take the 50 gram one to a designated RC park.
There is scientific evidence that any restraint on a child lowers his probable intelligence.

It seems to me I should get the lower nitro local fuel, as I don't want a lot of power.

Nitro is not real super critical, 20-25% is gonna be easier to start and give you a little more RPM than 10%, i would use shorter lines if you do. Back in the day, guys would mount prop backwards or used a disc or trainer prop to reduce speed.

I have a quart of fuel.  It is 20% nitromethane and 8% lubricant "synthetic and castor oil blend".  Last time I found castor oil at a drug store.  Otherwise I suppose I could add car oil.

Not sure about the Aluminum disk, but I like rubber spinners, because when my son was 4 1/2 I got him to fly my balsa trainer. I was so sure it was going to crash that I didn't step back and it hit me in the knee. It hurt for a minute but there was no mark. It had the spinner and special nut from the PT19.

Not sure if car oil would lubricate adequately? I would add oil to appx 25%-28% total volume. 8% seems awful low, what kind of fuel is it? I guess it's your call on what you want/expect, i've seen these engines loose compression in one or two flights.

8% oil content is low, perhaps a 4 cycle glow fuel? Someone some time back did a study on effective amount of Castor that will protect a glow engine. He concluded that if the fuel had at least 6% of total fuel volume as Castor (and rest non-Castor oil) was enough to protect during a lean hot run.

Following are calculations adding 12 oz. Castor (Byron's) to Wilcat 15% nitro fuel:



Following are calculations adding 16 oz. Castor (Klotz Benol Racing Castor) to Wilcat 15% nitro fuel:



Adding 12 oz. Castor ups fuel volume to 140 oz. with 23.2% total oil content and about 50% as Castor. Add 16 oz. Castor bumps fule to 144 oz. with 25.3% total oil volume, of which Castor is now 14% of fuel volume, 55% of oil volume.

The latter mix is what I use with my legacy cross scavenge engines.

I added 4 oz. of castor oil from a drug store to a quart of the car fuel. If I buy another order from SIG or such I'll get some fuel with it. I think what I have will do for now. I did something similar last time I ran engines and had no difficulty with it. The old fuel is brown after sitting for 10 years.

I've been half-heartedly looking for a Wen-Mac Bonanza for a little while. Only because I saw an episode of the Andy Griffith Show where Andy walks into Opie's room, and on the dresser behind Opie is a Wen-Mac Bonanza. If it's good enough for Opie, it's good enough for me.

The Mayberry Mark

batjac wrote:Only because I saw an episode of the Andy Griffith Show where Andy walks into Opie's room, and on the dresser behind Opie is a Wen-Mac Bonanza. If it's good enough for Opie, it's good enough for me. The Mayberry Mark

Here's control line on the Red Green Show.

David Ingham wrote:I added 4 oz. of castor oil from a drug store to a quart of the car fuel.  If I buy another order from SIG or such I'll get some fuel with it.  I think what I have will do for now.  I did something similar last time I ran engines and had no difficulty with it.  The old fuel is brown after sitting for 10 years.

David, I came up with the following numbers assuming for example, Byron's RACE 2500 Gen2 RC car fuel with 25% nitro with 8% oil of which half is Castor and half is Synth.

With 4 oz. Castor added to a quart:



With 5 oz. Castor added to a quart:



5 oz. Castor would bump oil level from 18% to 20%, which would be closer to general engine guru consensus of at least 20% oil content. Is 18% oil content with 15% as Castor by adding 4 oz. more Castor jeopardizing the engine? Probably not, I just thought you might be interested in the numbers.

My old power supply of 5 P D cells is soldered to a Cox clip. So I soldered 5 P AA cells to my clip made for engines with separate plugs. I am not expecting a lot of flying and I think that will supply the current.
If the engine runs, I plan to fly one of my old Cox engined airplanes a bit for practice before trying this one. I will have to guess about how much elevator travel. He included an elevator from a similar model, which will help. The shape should be the mirror image of the other half of the V.

I tried to start the engine, but just got pops.  I filled the tank, connected the clip and 5 AA cells, primed it in the exhaust port and flipped like I would flip a Cox without a spring.  Just pops.  Primed the intake, more pops.  I tried 1 1/2 turns of the needle valve and about three turns.  I need to check the fuel flow in the tube.  It is visible, but I forgot to look.

The closest sanctioned control line field listed on RC Groups is about an hours drive away. In the old days, I never had to go more than a block.

David Ingham wrote:I tried to start the engine, but just got pops.  I filled the tank, connected the clip and 5 AA cells, primed it in the exhaust port and flipped like I would flip a Cox without a spring.  Just pops.  Primed the intake, more pops.  I tried 1 1/2 turns of the needle valve and about three turns.  I need to check the fuel flow in the tube.  It is visible, but I forgot to look.

The closest sanctioned control line field listed on RC Groups is about an hours drive away.  In the old days, I never had to go more than a block.

Prime down the air intake rather than the exhaust & see if you still get a pop. Generally you can prime a little richer and the engine will give a short burst rather than a pop. If it does give a short burst then it sounds like the spray bar is blocked.

David Ingham wrote:Not sure about the Aluminum disk, but I like rubber spinners, because when my son was 4 1/2 I got him to fly my balsa trainer.  I was so sure it was going to crash that I didn't step back and it hit me in the knee.  It hurt for a minute but there was no mark.  It had the spinner and special nut from the PT19.

I had one of the big rubber cox spinners (PT-19 style) rob a ton of performance from a "built" reedy. I could get ~17-18K rpm on a 5x3 2 blade without it, but only around 14K with the spinner. It was on my mono-copter, and it flat wouldn't fly with the spinner. I'm at around 6,000'MSL, so 17K is pretty hot for a reedy at this altitude. I suspect that if you load it down with more prop (and more flywheel) it doesn't hurt as much.

Is there an industrial park nearby to you David? Chances are that on a weekend, there would be no activity. (no vehicles in the parking lots there).. and no one to disturb. I don't like the idea of flying over pavement.. but if you can find a spot where there's a transition to grass without a berm.. you could launch from the pavement. Try splitting the circle into 50/50 pavement/grass and have a helper release the model from the edge of the pavement. Position yourself (pilot) at the edge of the pavement also. This will provide a "roll-out" for the model and half the circle's circumference to get airborne. Once it's in the air, you could lead the model back over the grass area.. and clear of the pavement. If it crashes before you're completely over the grass.. you still have at least a 50% chance of it hitting grass.. vs. the pavement. Even if there's a berm or curbing, you could lay-out a carpet-runner over the curb on the opposing side of the launch area as a cushion.. in case the model doesn't clear-it on take-off. It's an easy item to bring with you. Just roll it up and toss it in the car. You might even be able to use it as a runway on grass.

You shouldn't have to drive that far to fly a little airplane on 20-foot lines... and if you happen to forget an item, it's just a short trip back to the hangar. Just a little food for thought..  

kevbo wrote:

David Ingham wrote:Not sure about the Aluminum disk, but I like rubber spinners, because when my son was 4 1/2 I got him to fly my balsa trainer.  I was so sure it was going to crash that I didn't step back and it hit me in the knee.  It hurt for a minute but there was no mark.  It had the spinner and special nut from the PT19.

I had one of the big rubber cox spinners (PT-19 style) rob a ton of performance from a "built" reedy.   I could get ~17-18K rpm on a 5x3 2 blade without it, but only around 14K with the spinner.  It was on my mono-copter, and it flat wouldn't fly with the spinner.  I'm at around 6,000'MSL, so 17K is pretty hot for a reedy at this altitude.   I suspect that if you load it down with more prop (and more flywheel) it doesn't hurt as much.

I cant imagine how the spinner would affect the RPM.