Can anyone tell me if the cyl and head from a "pipebomb" testors engine will interchange with the Mcoy 049?
I seem to have misplaced my Mcoy 049 or I would check for myself.
SkyStreak wrote: Can anyone tell me if the cyl and head from a "pipebomb" testors engine will interchange with the Mcoy 049?
As the last .049 that Testor made, according to Peter Chinn, the 8000 series reed valve engine, from which their RTF "pipe bomb" engine is based on, was definitely a hot one.
Peter Chinn wrote: Compared with the engine that it has replaced (the Testor McCoy 049), the 8000 was found to be considerably more powerful, with a maximum torque of 6.0 oz. in. at 11,000 rpm and a gross bhp (less silencer) of .094 at 18,000. This is very good indeed for what is basically a sport type reed-valve 049. In terms of prop speeds, the engine turned its own 5-1/2x3-1/2 Testor at 14,200 rpm. Other figures included 13,400 on a 6x4 Top Flite nylon, 13,900 on a 5-1/2x4 Cox grey nylon, 14,800 on a 6x3 Tornado nylon, 15,200 on a 6x3 Cox grey nylon, 15,700 on a 6x3 Top Flite nylon and 16,300 on a 5-1/4x4 Top Flite nylon.
Peter Chinn wrote: The Black Widow is intended for operation on fuels of a medium nitro rating - i.e. about 15 percent nitromethane. Using such a fuel, our test motor recorded a maximum torque of just over 6 oz.in. at around 9,000 r.p.m. and a peak output of nearly .08 b.h.p. at between 15,000 and 15,550 r.p.m. These are quite good figures for a 'sport' type .049 and are reflected in some useful prop speeds on various props.
Not only is top end interchangeable, needle valve (although a bit stumpy) works in any Wen_Mac or Testor-Mac FRV. and Rotomatic starter parts are interchangeable will all late version Testor-Mac FRVs. Springs can be made to work in anything. And if you do machine shop work, you can also do some cool experiments on re-timing and re-porting the solid un-relieved crankshafts found in many of the pipe bombs for use in FRV Testor-Macs and Men Macs. You will find all kinds of strange crankshafts in these pipe bombs though if you tear down enough of them. I've found at least four or five permutations of crankshafts so far.
I think that Wild Bill Netzband had a hand in the design. He was VERY smart and a nice guy as well.
Hey Yak-Nine, sorry we missed you. Welcome to the forum.
Good luck with the Cosmic Wind. I'm surprised it didn't fly. It should have at least gone round & round.
Personally, if the head still glows I wouldn't change it out for an adaptor. A better prop should help, as should a hearty dose of nitro. I'd use nothing less than 25%. Make sure it's well broken in before you attempt to fly. If it flew that poorly I'm betting it never got much run time.
I wonder what Yak-Nine's altitude MSL is.
I have a Cosmic Wind, fuselage and engine no wing. Won't get off the ground either.
My son flew our Cox powered Baby Ringmaster in Denver, the mile high city. Flew the same as it did at Pax River Maryland at maybe 15 feet.
There was a short period where Testors was selling RTF's with a fuel position valve instead of a needle valve. Problem was the manufactured valve did not perform as well as the prototype valve by engineering. It was shortly dropped and reverted back to the needle valve system.
Could your aircraft be one of those with a fuel position valve?
If it was recent that you ran your Cosmic Wind, could also be the glow head has gone bad. In the past glow head and glow plug manufacturers ran into supplier quality problems with the element wire supplied. The platinum, iridium or other rare element earth metals would somehow become unstable losing their catalytic action with methanol fuel.
Leroy Cox had a problem with glow heads from one of his subcontractors. Swanson Associates had some bad wire supplied to them also. I bought a card of their defective Fireball Red plugs on E-Bay may be 5 years ago. They'd work fine for a day or two. A week or two later, they'd glow, but fuel would barely fizz, the engine acted like it was trying to start, but just wouldn't crank up. Yet a new plug from the batch would cause it to fire up right away.
But I had no problem with their plugs of the 1970's, always fired up without a problem. And Bob, my apologies, I was composing my message while you sent yours.
Me begins to think that the Testors quality assurance curses plagued Wen Mac and McCoy products throughout their lifespan.
Here's some photos that I got from Google Images a while back..
Note; the "Zip-Starter".. I assume that your model had this option..?
The 1/2A RTF Cosmic Wind models are very cool-looking in my opinion, but under-powered. I wish you the best of luck with your engine-mods.
You may want to try tuning your engine for an APC 4.75" x 4" propeller. The APC prop is rigid.. and will stay true to its' pitch when running-up into the engines' power-band.
Shown below on my Cox .049 engine..
I needed to enlarge the bore in the props' "hub" to accommodate the Coxes' 5-40 machine (prop) screw; along with a self-centering bushing made from a short piece of silicone fuel tubing.
Unlike the Cox .049 engines which use prop-screws; the McCoy/Testors .049 engines utilize a (larger diameter) 6-32 threaded stud at the nose of their crankshafts. A 6-32 "nut and flat-washer" secure the propeller to the engine. I'm sure that you'll be able to make it all work!
Wow, that Cosmic Wind brings back memories. That was my very first plane I attempted to fly. My dad bought it from the son of a family friend back when I was 9 - 11 years old which would be 1987 - 1990. Had a try at it once in our back yard which backed on to a field. No go on take-off. So off to the community center parking lot a few houses away. Dad started it and I was at the handle. He let it go, it took off well, then started climbing and diving faster and faster till she hit ground zero and popped apart. Picked it up and went home. Dad bought a new prop and I can't remember about the spinner, but I know that it was smashed. While apart, I remember dad drilling a hole in teh bellcrank and screwing it 'close to neutral'. One more try, one more unsuccessful flight. Last I remember he still had it, but have not seen it in a while.
NEW222 wrote: Wow, that Cosmic Wind brings back memories. That was my very first plane I attempted to fly. My dad bought it from the son of a family friend back when I was 9 - 11 years old which would be 1987 - 1990. Had a try at it once in our back yard which backed on to a field. No go on take-off. So off to the community center parking lot a few houses away. Dad started it and I was at the handle. He let it go, it took off well, then started climbing and diving faster and faster till she hit ground zero and popped apart. Picked it up and went home. Dad bought a new prop and I can't remember about the spinner, but I know that it was smashed. While apart, I remember dad drilling a hole in teh bellcrank and screwing it 'close to neutral'. One more try, one more unsuccessful flight. Last I remember he still had it, but have not seen it in a while.
Chancey.. Thanks for sharing that memory here. I don't have many childhood memories of "my" taking-part in the flying of models. Reading "your" story is endearing.. because there "was" a significant amount of aero-modelling going-on in my family when I was a young boy; back in the 1960's. I didn't get involved (.. or show much interest..) until much later in life, as an adult. It was however with my dad; for which I'm thankful.
And to add. Mine did have the zip starter and I remewmber using it. However, I do vaguely remember seeing it broken many years ago and do not think my dad would have kept it.
The valve you talk about was only used on some reed valve engines. I'm pretty sure the Cosmic Wind used the front intake Testors/McCoy beam mount engine.
Thats interesting it has a zip starter i have seen them in pictures but not anyone using it or were would you put it through to keep tinchion ?
If you look at the second picture roddie posted you can see the spot. It is in between the cylinder and propeller. The cutout at top center. Carefully push the yellow starter down and watch the prop go in reverse. Then when ready, a steady firm pull up would start the engine.