Recent engine acquisitions

Thanks George. That Kavan extension was a very common mod in Finland ”back then”. I installed one on my first Bee in 1983 or so, I was 12 at the time. Kavan was the European importer of Cox products, even some glowheads had Kavan label on them.

I remember when I had saved enough money to go and buy my first engine, the alternatives at the local shop were Babe Bee, Black Widow and Tee Dee. Tee Dee was way over my budget, and the Black Widow was said to be a ”competition engine”, and was also quite pricey. So Babe Bee it was, and when I was concerned about the short running time (I was going to use it to launch an RC glider), the salesman showed the tank extension kit, which I bought too.

Had there been a Golden Bee, I probably would have bought it, but I think for some reason they were not imported to Finland in the ’80s. I could be wrong of course but one indication is the fact that I still don’t have a Golden Bee in my collection. I have maybe dozen or more Babe Bees, about 10 of which came with the extension kit installed To me it seems that a Bee without the kit is more rare than one that has it, so maybe I take them for granted. The kit is also sometimes considered ”problematic” as it doubles the amount of potential leak points.

Still, now that you mentioned it, and also after giving it some thought, the kit is a part of the history of that particular engine, so I think I will install it after all. I know the talk about ”history” may sound weird, but I have been involved with some museum people and they don’t like to make things necessarily look like ”new”, ”factory” or ”period correct”, but instead want to see the signs of life and use of that particular piece. These folks are mostly involved in conserving buildings, furniture, vehicles etc but also small objects, and it sort of struck a chord when I was thinking about my engines, many of them older than myself

Nice job Kari...with so many hours on this engine eating the crankcase away I wonder what level of compression was left in the cylinder  and piston set? Is this a No1 or 2 cylinder? Also, did you try adding a TD thrust washer to reduce the axial play of the shaft? The crankcase has a widened nose and that may match the washer dimensions..if not a TD washer maybe a metric one from your toolbox?

Enjoyed reading about your Cox BB rebuild Kari and the pictures. Never grows old.

That red tank extender. Bad memories. Leading down from the loft is a set of stairs where I found this red plastic ring thing. Didn't know what it was but I set it up on the window sill. Stayed there for weeks until I finally threw it away.

Next day I signed on here and sure enough someone was discussing those red extenders. Only one I have ever seen in the flesh, and I tossed it. Still make me angry. It must have come in a Cox lot of parts and rolled away.

Bob

balogh wrote:Nice job Kari...with so many hours on this engine eating the crankcase away I wonder what level of compression was left in the cylinder  and piston set? Is this a No1 or 2 cylinder? Also, did you try adding a TD thrust washer to reduce the axial play of the shaft? The crankcase has a widened nose and that may match the washer dimensions..if not a TD washer maybe a metric one from your toolbox?

Thanks Andras, the compression is surprisingly good, almost like new. The rod was a little loose, definitely not excessively so, but it did need a reset. About the crankcase wear, I remember reading a warning to not polish the crankcase bearing area, as it would remove the anodizing and cause rapid wear of the surfaces. I am pretty sure this engine has not been apart, but maybe there was a batch of crankcases with sub-standard anodizing at some point? Or maybe some glitch in the aluminum extrusion process or the alloy itself? The QZ I posted about earlier, it is about the same vintage and it also had a similar condition. Just speculating. These two cases are the worst I have seen, but I also have some obviously low-mileage product engines that have slight play in the ”wrong way”. These cases do seem to polish easily, so they are good for showpieces I have never seen this condition in new style cases.

Not sure yet what to do with the axial play, I’m not sure if that is a problem since I am not going to use this one in a pusher application. I have another case with good bearings and I think it also has less axial play but it has some deep scratches that I will need to sand out first. We’ll see

rsv1cox wrote:
That red tank extender.  

Hey Bob, I have a few of those, no way I’ll need all of them, so if you want one, maybe we can arrange something

Thanks for the kind words too.

Thanks Kari..a disproportional crankcase wear may also be a result of unbalanced propellers...though you mentioned the person donating the engines to you was a longtime modeller so he must have taken good care of the prop balance.

With the thrust washer - even if I  do not use the engine in pusher mode nor use an electric starter- some of the axial play could be eliminated. At least I used this method on a fairly used TD 020 to mimimize axial play[im5g]https://i.servimg.com/u/f48/19/92/56/25/15396310.jpg[/img]

In my experience excessive axial play may allow the crankpin to rub the backplate when you occassionally use electric starters

The nice thing about the Bee engines is that they don't need to be electrically started. A washer to take up crankshaft play is not needed for a tractor engine and right hand prop. Flip starting has always worked with me. A Bee with a good glow head and no problems would start up with a couple flips. A spring starter makes it that much easier plus helps to ensure it ran in the right direction.

balogh wrote:Thanks Kari..a disproportional crankcase wear may also be a result of unbalanced propellers...though you mentioned the person donating the engines to you was a longtime modeller so he must have taken good care of the prop balance.

Yes, he does have a long history in the hobby. But this may well have been his first engine so the use with an unbalanced propeller is not impossible. And mistakes happen to even the smartest of us

Ok, I decided to install the tank extender after all. Here it is:

It can be a winner of Engine of the Month. Very good work.

Kari, agree with Levent, engine looks really good now, even better with the extender. I think you are right, what you have is how a modeler most likely would have modified the Babe Bee to provide extended flight times for RC back then. Can't say why Graupner only imported the extended tank Black Widow and not the Golden Bee. Perhaps they felt that there would not be much of a demand for the Golden Bee. Also I am wondering if perhaps at that time, Cox wasn't making as many Golden Bees and perhaps limited the market to say, US only, or perhaps for a number of years the Golden Bee was discontinued.

My OS .099 Pet finally arrived. Seller accidentally sent me the wrong .099; one I received was the later Pet CL version, not the earlier RC version (both were listed and ended at the same time), but I was able to negotiate a partial refund. Here's the engine as received:




Engine appears to be lightly used, was frozen from Castor, so into the hot antifreeze bath it went. After overnight, I could remove the cylinder liner, complete disassembly and continue soaking another day. After a little cleaning and polishing, replacing the prop drive hub (old the key was partly broken off probably from someone moving the prop on the frozen engine) and installing an NOS muffler.








One thing I had to do was rebend the muffler mount spring. The spring was a touch too short as bent, seems to be simple music wire. I straightened the original bends and moved it further out. Now it holds, but a good hard landing and it will dislodge. Now I understand why on later engines OS went to a spring steel strap fastened by the screws.

Not long ago, I bought a JIS screwdriver set. The #1 JIS Phillips came in handy. It grabs the screw head without chewing it up like with the standard Western Phillips screwdrivers. This is the way to go. Mounting a prop and oiling the engine, it has new engine compression, it definitely is a low time engine.

I hate to simply throw these away. If anyone is interested in the leftover empty OS parts label and bag, PM me and I'll mail to you via USPS.

Levent Suberk wrote:It can be a winner of Engine of the Month. Very good work.

Thanks Levent With all the great photos of rare and special engines posted lately to the EoM poll, it is hard to compete with an ordinary engine like this, but I just may enter it next month

Kari the Bee keeper

GallopingGhostler wrote:Kari, agree with Levent, engine looks really good now, even better with the extender. I think you are right, what you have is how a modeler most likely would have modified the Babe Bee to provide extended flight times for RC back then. Can't say why Graupner only imported the extended tank Black Widow and not the Golden Bee. Perhaps they felt that there would not be much of a demand for the Golden Bee. Also I am wondering if perhaps at that time, Cox wasn't making as many Golden Bees and perhaps limited the market to say, US only, or perhaps for a number of years the Golden Bee was discontinued.

Thanks! You’re right, Graupner was the importer, not Kavan. I am not certain whether or not the GB was a part of the import program but it seems that there are not many of them around for some reason. On the other hand, TeeDee .051 are relatively common unlike elsewhere (I think). Could be that the Finnish importer bought a large batch of stuff at a time and sold them off over a longer period of time. So, if at one time when it was time to buy stuff, GB’s were not available, could be that GB’s were not available for a few years after that in Finland. But the market here was/is small volume, so it may have been a strategig choice to limit the amount of products too.

But anyway, I still am looking for that Golden Bee

Edit: Nice Pet! I like the style of the silencer, very ”old school”

Decided to clean up the ”Barn Find QZ”. Unfortunately the fuel hose nipple broke from the back plate, so I needed to cannibalize a Babe Bee with a seized cylinder. That backplate is not perfect, but will do at least for now. The crank bearings were sloppy so the crankcase was replaced too. The new one is probably from one of the product engines with #1 cylinder that I have dismantled for other projects. Anyway, here are a couple of pics.





Turned out pretty nice.

While I was at it and the ultrasonic was hot, I grabbed one of my recently “adopted” Dragonflies. It was seized and sticky all over, but a hot bath in ethanol based windshield washer fluid (experimenting with this since I accidentally grabbed a half-gallon of it instead of the camping stove fluid I normally use) for the metal parts and hot water with dish washing detergent for the tank took care of it. The piston was seized in the cylinder, I got it out but it would not go past the top of exhaust ports. Fortunately in the pile-o-parts was a brand new cylinder and piston along with a gasket set so I utilized them in this build. There was no severe oxidation in any of the parts so the crankshaft was the only part that got polished, others just got a good rub with a terry cloth (actually it was a part of my old bathrobe recycled ). Now that I look at it I think I should have paid more attention to the muffler-throttle, it looks a bit smudgy. But I think I will make this engine a runner, since it has the new cylinder, and the other one will end up to be the polished collection piece. So this one will eventually receive a round driveplate and a no-drag starter spring. And I will try to hone the old cylinder and make it usable eventually.

Here are the pics:

Just purchased this engine:

It needs a 5ba prop screw and the needle doesnt look correct.
The glow plug is thought to possibly be a Cox part but everything else is British.
Waiting for it to get here so I can fire it up

ukanduit wrote:Just purchased this engine:


It needs a 5ba prop screw and the needle doesnt look correct. The glow plug is thought to possibly be a Cox part but everything else is British. Waiting for it to get here so I can fire it up

Nice, you don't see those very often, this is the first time I've seen this engine. Sceptre Flight has 2 articles on it. As a reedy, its power was a touch less than the Babe Bee. Otherwise, seemed to be a nice running engine.

Sceptre Flight Model Engine Tests, Keilkraft Cobra

Sceptre Flight Model Engine Tests, Keilkraft Cobra (2)

Adrian Duncan has a nice article on the http://www.modelenginenews.org/ad/kkcobra.html.
Thanks for the links.

This just in.... Got me a couple of awesome little engines today in the mail. I am very happy with the assortment, and will have a bunch of fun this winter rebuilding and cleaning these up. As well as researching and studying up on these. So far, I will list what I can safely identify.
Left to right, top row first
OK Cub 049A, OK Cub (model unknown), OK Cub .099, Ok Cub .074

Left to right, bottom row
Aurora Tornado .049, Unknown, Wen Mac 049 MK II

The only markings on the unknown engine is the word 'Comet' on the left side under the cylinder.

The Comet engine is a Fox .049 made for Comet for use in its line of plastic RTF planes. It may have come from a Comet plane post-consumer or it could have been one re-possessed by Duke Fox when Comet Models and Hobbycrafts of Chicago, IL wasn't paying its bills. Herkimer OK Cub also had same sort of trouble with Comet under similar arrangements.

Thank you. I was kind of thinking Fox, until I saw the 'Comet' on the side. The only othrer sort-of mystery is the second Cub on teh top row. It is just stamped Cub, with no size. As well, I had not personally seen one with a fuel tank like that. Off to the web to do some searching....

I can't comment on the Comet .049 but I know a lot of these engines were Fox .07's. This was due to the Comet planes being too heavy which is why OK made the .059 to power these lead sleds.  Same case and virtually identical. One identification is the top of the piston, one has a small bump on the top and the other is flat. I confuse which is which . Many of the Comet logo's were ground off when returned to Fox and resold with a small rectangular blemish .Fox also cut the tank off making a backplate out of it. It looks like they did it with a hacksaw. The .049 piston has a bump on the top of the piston in the middle of it when you remove the glow plug, the .07 is flat. Another identification is where the base of the liner mates to the case, the base is very thin on the .07 and thick on the .049. In addition, one cylinder has 7 fins the other has 8.  Looking at your engine, it looks thin making it a .07.

        This is the .049 and you can see the base flange is considerably thicker than the above .07 you can also see where the Comet logo was ground off by Fox

         These engines used a swaged piston to rod similar to a Cox .049. Whatever you do don't tighten this connection as you will destroy the piston and it will shatter into pieces. These engine run quite well but the plugs are the achilles heel. They will work then it will just shut off like someone threw a switch. The best solution is to drill out the post and tap it for a 1/4-32 plug. This engine doesn't really suffer too bad when this is done unlike many other 1/2 A engines. Plugs can be somewhat difficult to source for this engine. Bob Matte offers a very neat setup for the Fox .049 and .07 plugs.