GallopingGhostler

In a Cox Engines Forum thread:

Cox Engine Forums (t17045): Plans to Revive the Cox .049 Tee Dee? He poses a "straw poll" question:
Initial thoughts are possibly under $100 US, although cost is pending contractor quotes for various production parts he does not have stocked, so it could be less or more. He wants to make cost favourable to the customer, but remember, it must also be fair to him, so he profits decently, too. (He has to eat and pay bills, too, stay in business. )

If you are interested, you may follow the discussion there. Also, it would be good for you to provide your inputs, also. If he knows he has a product people are interested in, would help him with the impetus to proceed with such a project.

I think that it would be great to obtain a new classic high performance half-A engine at a reasonable price from a reputable, trusted dealer would be a plus over taking one's chances with an unknown seller.

Your thoughts?

706jim

Unless he has a slew of pistons and cylinders I don't think it is practical. I believe the market is just too small compared to when those engines were originally marketed.
The investment in equipment that Cox originally made was offset by the huge production numbers of that time. For relatively small numbers the price will be just too high IMO.

GallopingGhostler

About 15 years ago, Cox International (Canada), Ex Model Engines (US) and I think another purchased the left over cache of Cox engine parts from Estes parent company. I could be wrong, but recall it was around enough parts plus whole engines to the tune of 25,000. You are correct that the demand is not as high as it would be when the original Cox company was in existence, then after when Leisure Dynamics purchased Cox. But, there still is a demand as evidenced on Internet auction sales and prices, most stock being from sellers who purchased estate sales engines from deceased baby boomers. Those under $100 are usually less than pristine IMO, but NOS, clean used but unabused and especially in original boxes with docs definitely go for over $100.

Have you seen the prices for Norvels from their website? All are definitely over $100.

Then, the resources are available for a limited production to meet current demand. Initial thoughts were possibly $89 plus tax and shipping, but he didn't have all the numbers in yet from contractor quotes for various miscellaneous parts needed to complete these. Given that now we have active inflation, I don't think that prices are high considering.

However, if you want a Medallion, with care and patience can pick those up fairly cheap. I bought an NOS Cox .09 Medallion R/C with exhaust throttle muffler ring for under $50 several years ago, and a mislabeled, used but not abused earlier Medallion .049 (only fault a sheered off venturi plastic tap nipple (that I wouldn't drill through and use anyway) for $22.15 total.

049flyer

My Feedback: (18)

It’s hard to say what the worldwide market demand would be for new .049 TD engines. There are thousands of TDs floating around now, I have close to 20 of just the .049/.051 size, plus some of the .09s and .15s. Are good used engines that hard to find? Even so, I think that he could easily sell the first batch of 500 or maybe even 1000 but what is the game plan after that?

I would think that it might be better to buy up as many as possible and “factory” recondition/certify them for resale or perhaps manufacture parts to support the existing engines in the field. I have several that are sidelined for lack of parts.

But the REAL unknown is, can he REALLY produce EXACT copies with the same performance? It seems that engine manufacturing is not as simple as many seem to think, as evidenced by the tremendous number of manufacturers lost to history over the years. The task seems especially difficult for small engines and even more so for small high performance engines.

All that aside, I prefer the Medallion series myself. I find them much easier run, tune and more tolerant of low nitro fuel. Sure, they aren’t as powerful as the TDs but with today’s lightweight gear does it really matter?

GallopingGhostler

He's already got most of the parts from his 2009 purchase of the Estes Cox inventory. Plus, he has the original drawings. I have confidence in his abilities, already put in a request for one.

aspeed

I think it should be a good venture. I heard 1,000 units. Maybe making the fine thread needle valve too. I really don't see why they would bother making the old stock needle assembly, but more power to them. Only issue I can see is the muffler situation that most clubs insist on. It would be great if the Conquest was made, but MECOA hogged that one and likely won't bother with it AFAIK. It's great to see any motors being made again after everything has stopped production. I am not a fan of the Medallions. I only have one, but it is much lower on power than my Babe Bees, although it runs steadier. Maybe just my examples. A single bypass cylinder could be substituted. I am sure the guys would do that as a custom thing.

GallopingGhostler

Yes, I agree, aspeed. Bernie has already indicated he has most of the parts. Gauging by things out of stock on his website, I gather he may lack some of the finer things like needle valve rachet spring, phenolic prop drive plate washer, etc. Otherwise, he has the rest of the parts, including the SPI cylinders and pistons. It will have the non-tapered cylinders typical of the post L.M. Cox Company after sale to Leisure Dynamics, part was phased out.

Been on the back burner, but I am upgrading my earlier .049 Medallion with SPI to R/C with a legacy kit silicon throttle muffler kit obtained a couple years ago.

This ought to convert the Medallion to a nice and reasonably powerful engine. It eliminates power robbing exhaust gas recirculation under muffled conditions, has cylinder has dual internal bypasses to make up for the lack of SPI. Plus, similar to my same vintage R/C Bee, (which was more powerful than a Babe Bee), if muffling not needed, one can remove the silicon muffler cover and obtain wide open power of the engine.

aspeed

I have one of those mufflers too. First time I tried it the revs went up and down. Didn't know it was a throttle too. Opened up the slots so it worked only as a muffler. Wish I didn't do that now that I fly some RC. I guess I could machine another ring up. I have heard rumours that the silicone piece hardens up over time with a lot of use. Never used mine on a plane.

049flyer

My Feedback: (18)

My Medallions have about the same power as a Black Widow maybe a tiny bit more BUT they are much easier to start, easier to tune and run steady. The tanked engines suffer from two problems that are eliminated with the Medallion, the venturi gasket and the reed. Both contribute to problems, when they work they are awesome but when they don’t they are horrible.

I find the TDs to be great with high nitro fuels, pressure, and smallish props, but with low nitro or larger props they just are not as reliable and harder to start, probably a fuel draw thing. I would happily trade Medallions for TDs, especially if I could find some Medallion needle valves and spray bars.

aspeed

You know you can just solder up the hole where the needle goes in, and then use a remote needle. May cost a bit but it works good and keeps your fingers away from the prop. If you don't have the spray bar, you can use a bolt and drill a hole through the middle not quite through. Kind of make a long pressure fitting. I use the lathe but something can be figured out. I have not done it on a medallion, but maybe a surestart needle valve assembly or whatever may be usable. An OS needle from an rc smaller engine works as a remote.

GallopingGhostler

It is not hard to understand why the mylar reeds will wear out over time. Figure on 15,000 RPM with 3 minute flights and 500 flights over a couple year period. That is 22.5 million flex cycles that plastic reed underwent. My guess is that it probably got work hardened (or softened). If otherwise it fit properly with sufficient clearance from the wire retainer ring or other retainer, then it makes sense to periodically replace the reed.

The brass reeds seemed to work almost forever. I had enough of my share of crashes, that I never quite achieved totally wearing out a Cox engine, except with the R/C Bee. It was on its second cylinder with matching piston before I put it in hibernation.

Regarding the silicon muffler, it has some cracking inside from the heat and some blackening, but so far it is still good. But of course I flew it more often than not with it off the engine. You don't have the same luxury with the aluminum machined mufflers with rotating spring steel cover. Instead of all the perimeter exposed, it has only one slit a little wider than the exhaust throttle slot. The exhaust port on the opposite side doesn't exit directly to atmosphere.

I heard a story that Cox dropped the silicon muffler idea, because they were contacted over a patent breech. Cox quickly discontinued the product and moved on to their all metal throttle muffler design with the Dragonfly engine. Curiosity killed the cat, I got myself a Dragonfly engine and related non-throttled Ranger product engine. 9 lives, no 8 lives, no, now 7 lives left.

aspeed

I've worn out a few Bees from leaking out of the crank at the front. Would just rev up, slow down, rev up... Also one TD .051 piston cyl. . Got it well used and ran it a few times, but it was just too hard to start with no compression even with the starter. Don't fly the small stuff any more, just too windy where I live now. Need at least a .15. The club here requires a muffler and a means to shut off as well. Still can fly control line at another field no problem.

GallopingGhostler

I'm in the same boat as you, aspeed. We have few trees here in the desert like eastern New Mexico. Winds are usually over 15 mph at the flying field. The reed valves just don't cut it. One can get by with a decent .09, but .15's and up or the electrical equivalent are the norm.

A Tee Dee wide open that runs reliably will be able to more or less make it. A friend was flying his hopped up Medallion .049 on a Baby Clown C/L job, it did quite adequately. The Medallion was the poor man's Tee Dee back in the day. Replacing the cylinder with a standard Tee Dee cylinder and Tee Dee higher compression head made it approach the Tee Dee. The slightly more restrictive venturi set up gave it adequate suction feed.

But, I know what you are saying about field conditions not being as conducive to small engine planes overall. That is why flying single channel rudder only is a no-go. We may be have 4 or so days with calm winds in a year's time.

JPRC74

- a efw good cox complete 049 ; and 020; and parts if interests....

GallopingGhostler

Sounds like there was enough slop in the crankcase crankshaft bore, that it was leaking some air in through the bearing opening into the crankcase. You really got your mileage on these Bees. (For clarinet keywork, one would swedge the end with a special type of crimping tool that would take up the worn slack narrowing the inner diameter to fit the holding screw shaft. Would be interesting to use such tool on the older tapered nosed Bee crankcases. Or, even use an automobile engine tappet guide knurling tool.) Fortunately for the Bees, except for the earliest (Thermal Hopper et. al.), there are replacement crankcases and crankshafts still available, if one doesn't mind losing a little historic look with the later straight crankcase noses.

I guess, now you have a shelf display item. I just got one recently, it was a runner but still has good compression. Need to replace the red carb body and prop thrust plate, install a new venturi. Fortunately it came with the NVA assembly compĺete with needle, spring and spray body, plus an accessory pylon engine mount for a glider.