Testors plastic crank case engines

Jason_WI wrote:I got 3 Testors plastic crank case engines today. There are 3 of them and all 3 are different. The one with the hole on the side is front rotary valve induction and no needle valve. Not sure what these were used on. Any information will be helpful.

They are good for parts to get usable Wen-Mac/McCoy/Testors .049s going, but not much else!

Are they really plastic crankcases? They have that cast pot-metal look to them.

Those are nylon. They also made some cast metal case versions.

RknRusty wrote:Are they really plastic crankcases? They have that cast pot-metal look to them.

I believe they are a glass reinforced plastic, they have metal inserts as crankshaft bearings and where the cylinder etc. screws in. they actually run very well, but there is no way of mounting them in any other model, however, there is a version called the 8000 which has the plastic crankcase and a built in tank with mounting lugs which I would love to add to my collection, and also a version with a plastic mounting bracket on the rear which is also usable, both of these, in my experience, are quite rare.

Wilf

Here you go................



This tells you exactly what the crankcase is made of, and the specs. are very similar to the engines you have

Thanks for the test report. What is strange is the front rotary valve version does not have a needle valve. I do not see where one can be attached unless it is missing a venturi that goes in on the hole on the side. These are very strange engines that were made to cut all costs.

Jason

Jason_WI wrote:Thanks for the test report. What is strange is the front rotary valve version does not have a needle valve. I do not see where one can be attached unless it is missing a venturi that goes in on the hole on the side. These are very strange engines that were made to cut all costs.

Jason

I've never come across a front rotary version, any chance of a few more pictures of this one, especially from the front showing this "Front rotary"? I have a list of just about every Wen-Mac/McCoy/Testors .049, all 27 distinct models, plus variants, which were ever made, I might find something in that with a few more details.

Here is a picture of the side of the engine showing the front rotary valve intake on the side of the crank case. There is no needle valve. The long tube from the tank partially closes the intake venturi.



This picture shows the rear of the engine with the tank removed. You can see the hole in the crank shaft for the intake.



Here is a picture of the entire engine with the tank separated from the crank case.



Hope this helps in identifying this engine.

Jason

Jason_WI wrote:Here is a picture of the side of the engine showing the front rotary
Hope this helps in identifying this engine.

Jason

Curioser and curioser! That is the strangest "Pipebomb" I've ever seen! I assume that, as you said earlier, there was a push-in venturi there on the side of the engine which is missing.
This was obviously designed for one particular model, plane/car/whatever.
I will go into my listing of Wen-Macs and see what I can find, unfortunately the lists are old and discoloured, and were badly typed to start with. I am in the middle of re-typing them and I am having difficulty reading some of it. I'll come back with anything I find.
It would be interesting to find out just WHAT this was for.

Wilf

I've been through my listing of Wen-Mac etc. engines, and unfortunately it doesn't cover the "Pipebombs"
I have, however, posted a request on the .049 Collectors Forum to see if they can come up with any information, this really intrigues me and I'm determined to find out about this engine!

Wilf

Mystery solved, Jason! Your engine never had a proper venturi or needlevalve, just a four position fuel-metering valve, as detailed in the attached report
I knew someone on the Vintage Glow Engines thread on RC Models would know the answer!

Thanks for the information!. It looks like I'm missing the metering valve so running it may be out of the question. I could thread in a TD 049 venturi with a NV assembly and run it that way. I could turn a new backplate and have a radial mount type. The problerm is how to secure the rear radial mount since it snaps into the crankcase. It may be a futile effort.

Jason

Like the new "avie" Wilf. Are you going to have some shoulder patches made up for us?

You can buy the SAD patches from AMA:

http://www.modelaircraft.org/shopama/product.aspx?id=69CAE3DA05FB4A2BA1284265DF5B5275&d=CA5F1232E8744C868FE386FE3BFDC73

Jason

Jason_WI wrote:You can buy the SAD patches from AMA:

http://www.modelaircraft.org/shopama/product.aspx?id=69CAE3DA05FB4A2BA1284265DF5B5275&d=CA5F1232E8744C868FE386FE3BFDC73

Jason

Yes, I must get some!

I've had some more interesting information about these engines sent to me, this is an excerpt from an interview with Bill Netzeband, who was for many years, one of the designers at Testors, the interesting bit is where he talks about the very engine we have been discussing.....

" I have very little dated information saved from the 13 years at TESTOR here in California. I joined them in 1963, and did all of the design of the RTF planes and engines, spilling over into powered cars, foam gliders, and the redesign and upgrading of several old WEN-MAC products.

Here are the brief answers to your questions.


A couple quick questions for starters....

Where were the plastic RTF's made, engines? (These products were manufactured in Santa Monica, CA until 1980, when this facility was moved to San Diego and production was scaled back).

What was made in Rockford? ( The Rockford facility, original TESTOR CORP plant, made hobby paint, and several lines of gliders for premium sales. The balsa products were manufactured there during the 50's and 60's).

What years did you live here? (Actually we never lived in Rockford. The California facility consisted of the Duromatic engine Company, and TESTOR, housed in the former WEN-MAC buildings).

Was there ever a Testors DR-1? Some have claimed to have seen it advertised? ( I made drawings and a prototype model of the FOKKER Dr-1, when we did several WW1 FLY 'EM's). Otherwise I don't recall any products designated "DR-1).

What was up with the fly'em engine with no threads on the needle? When was that made? ( The no-thread "fuel control" was an attempt to fit an engine with a single turn valve, which had logical sequence positions to provide, 1- Wide open to prime intake during tank filling; 2- RICH mix to start cold: and a "RUN" range to lean out the mixture to "speed up" the engine. There was a position to shut off fuel, in order to crank off a "flood", or to quickly "kill the engine. We got suckered by making prototype parts that performed exactly as designed. During the first production run, it became clear that we couldn't MOLD the plastic valve stem and the mating slot in the plastic tank consistently enough to cover the minute range of metering area to do the same job as the prototype machined parts! Unfortunately, we were committed to ship quite a few defective products, before going back to the "venerable" needle valve system).

There never seems to be enough lead time to complete and test a perfect product design, but plenty of time to "do-over".

Best Regards Bill Netzeband "

Here is a pic of the Testor's 8000 engine. I believe the name came from the displacement .8cc (.049ci).
The lower right shows the "fill cap" that is put in the fill hole on the tank. The engine was packaged bottom up. It was configured for CL with the cylinder placed to the outside of the circle. The version with the metal crankcase (possibly more weight for balance?) earned it the nickname "pipe bomb" engine. Sorry for the blurred pic. 
 

 


Forgot to mention...they run pretty well.

George

I find an interesting thing about the Testors 8000 engine is that it fits the Cox tank engine bolt pattern. Here's some interesting facts from Peter Chinn. I am also including the Cox Black Widow for comparison. Please note that I have only included the essential text, less important text such as temperature are barometric pressure are not shown.

TESTORS .049 8000:

http://www.sceptreflight.net/Model%20Engine%20Tests/Testor%208000%20(2).html wrote:TEST CONDITIONS
Running time prior to test: 1 hour approx.
Fuel used: 15% pure nitromethane, 20% castor-oil, 65% methanol

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 polypropylene propeller at 14,600 and a 5x4 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.

The 8000 was also checked with the muffler ring installed. This reduced maximum torque to 5.3 oz in. and peak output to approximately .077 bhp at 17,000 rpm. Prop revs were reduced by between 800 and 1,100 rpm on the most useful sizes.

Cox .049 Black Widow:

http://www.sceptreflight.net/Model%20Engine%20Tests/Cox%20Black%20Widow.html wrote:TEST CONDITIONS
Running time prior to test: Approx 15 minutes
Fuel used: 15 per cent nitromethane, 25 per cent Newton R Castor-oil, 60 per cent methanol

The Black Widow is intended for operation on fuels of a medium nitro rating - i.e. about 15 per cent nitromethane. Using such 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 speeds on various props.

The most useful prop sizes with the Black Widow should be 6x4 for a control-line stunt or sport and a 6x3 or 'fast' 6x4 for free-flight although, should the need arise, the engine is capable of turning 7 in. diameter props of 3 to 4 in. pitch, such as one might wish to use for a large 'motor-glider' type model for example.

Prop speeds recorded on test included 10,600 r.p.m. on a 7x4 Taipan nylon-glassfibre, 11,200 on a 7x3-1/2 Bartels epoxy-glassfibre, 12,000 on a 7x3 TopFlite wood, 12,600 on a 6x4 Tornado nylon, 13,000 on a 6x4 TopFlite nylon, 13,800 on a 6x4 McCoy nylon, 13,900 on a 6x3 KeilKraft nylon. 14,000 on a 6x3 Tornado nylon, 14,600 on a 6x3 TopFlite nylon and 15,500 on a 6x4 (nominal) DC nylon. The Black Widow was also checked on 5-1/2x3 and 5x4 Tornado nylon props but these took it up to over 16,000 r.pm. static which probably means rising to 17,500-18,000 in flight and, as the b.h.p. curve indicates, there would be no advantage in propping the engine for more than say, 16,000 in flight.

Please note that there is a slight variation of fuel used, the Testors 20% oil whereas the Cox is 25% oil. Also, the Testors was run 1 hour, Cox 15 minutes for break in. I don't know how much this would affect the results, but we see the Testors at 0.94 BHP at 18,000 RPM, the Cox 0.8 BHP at 15,500 RPM. Both developed the same torque. Both on TopFlite 6x3 nylon prop: Testors - 15,700 RPM, Cox - 14,600 RPM.

The Testors 8000 at this point does appear to have a slight edge over the Cox Black Widow, IMO. I think OTOH, the Cox might have a slight edge turning larger propellers like a 7x3 for say, powered gliders.

Speaking of the ability for Cox reed valves turning larger props, back in the 1970's, I found that their humble .020 Pee Wee with a TopFlite 5-1/4x3 nylon flew a 27" TopFlite Schoolboy R/O RC at about the same speed as the Cox Grey 4-1/2x2 prop but with about double the run time.

Here's something interesting too, looking at the Sceptre Flight website. The 1970 Testors .049 Rotomatic was comparable to the 1961 Cox .049 Golden Bee in performance. I have the latest version with the Red Head glow head purchased some time in the 1980's. I hope I'm not boring you with Peter Chinn's write up.

http://www.sceptreflight.net/Model%20Engine%20Tests/Testors%20McCoy%20.049%20Rotomatic.html wrote:On the 6x4 McCoy prop supplied and using the maker's own recommended fuel, we obtained 12,800 rpm static (12,700 rpm on the second motor). The prop is obviously very well matched to the engine since, when load is reducted in flight the prop should speed up to a figure quite close to the revolutions at which the engne develops its peak power. Torque tests indicated that the McCoy delivered approximately .062 bhp at between 14,500 and 15,000 rpm.

We also checked the engine on a variety of other prop sizes and obtained the following: 9900 rpm on a 7x3 Top-Flite wood, 11,100 on a 6x4 Power-Prop wood, 11,300 on a 6x4 Tornado nylon, 11,900 on a 6x4 Top-Flite nylon, 13,500 on a 6x3 Tornado nylon, 14,200 on a 6x3 Top-Flite nylon, 13,500 on a 5-1/2x4 Tornado nylon and 16,500 on a 5x3 Tornado nylon. the engine ran well on all these. Several runs at over 16,000 rpm were made and the original glowhead survived all tests.

As far as I remember, the Wen Mac and Testors with glow head (not glow plug) were decent engines, giving power at least comparable to the Baby Bee and perhaps more.

For comparison, here are .049 RPM values from the Sceptre Flight article archive results with TopFlite 6x3 nylon prop (variations noted):

10,600  Frog (Tornado 6x3 wood)
11,500  Anderson Royal Baby Spitfire
11,500  Wen Mac (6x3 narrow blade wood)
12,000  Allyn Sky Fury
13,050  Atwood Shriek
14,100  Cox QZ (Sure Start ancestor)
14,200  Testors Rotomatic
14,400  Cox Babe Bee
14,600  Cox Black Widow (note, I think this ought to be higher, may be fuel related)
15,100  K&B Stallion
15,200  Cox Golden Bee
15,200  Wen Mac Hot Shot
15,700  Testors 8000
17,500  Cox .074 Queen Bee (Cox 6x3)
18,300  Tee Dee

Thanks George's ; I have never had the 8000 in hand before but sounds pretty impressive < just got rid of 3 Testors 10-  

You're welcome, Eric. The one in the upper left is in fact a Testors 8000. Nice thing about the 8000 is that it comes up on E-Bay occasionally for a song, there may be others in this forum willing to part with one with a horse trade ....

I think the Black Widow would be on par with the 8000. Would be interested in numbers for the true "Killer Bee" (not Estes mis-matched parts one).

For RC, one would run the 8000 inverted so tank fuel pick is on the bottom, but I don't know how well the engine runs inverted. Some have mentioned twisting the engine orientation, but I'd think it would be possible to break the tank alignment keying pin. Vibration might cause it to change orientation. I don't know if this would be true in real life.

I found it interesting that some of the earlier .049 engines had the power of the Cox .020 Pee Wee. I don't know specifically where the OK CUb .049 A's and B's would be, but imagine their power output was similar to the earlier glow plug based Wen Mac.

Where can you get parts for these ? Reeds? Needles? I just received one never been run. I can start it but it won't stay running revs up and quits before I can tune needle

nickmorang wrote:Where can you get parts for these  ?  Reeds? Needles?  I just received one never been run. I can start it but it won't stay running    revs up and quits before I can tune needle

Hey, welcome. Will pay to read back over the whole post.
You'll just need to search auction sites etc. Parts come up every now & then, but there's no huge stockpile of new unsold parts like there was with Cox & OK Cubs, not that anyone is selling anyway. Heads and needles come up regularly. Never seen a reed, but I haven't seen an original Testors mylar reed fail. It's probably just stuck.
Which type engine is it?

Rod.