Cox TD RC .050 Carburetor question
Does anyone know if the TD RC .050 carburetor assembly will work in the TD 049/051 engines?
If it would help I have a used .05 Tee Dee R/C I could ship up to you for experimentation. I could get it off to you by early next week. All I ask is that you return the motor when done. I will be back on line here tomorrow night so just keep me posted.
Bob
on a standard old TeeDee 051 and it worked well.
I imagine the Cox carb with a muffler on either the 049 or 051
would work as well. I can check to make
sure the TeeDee I used had SPI. I have heard the muffler
helped keep it hot at lower RPMs and stay running. The Tarno
reportedly did not work so well w/o a muffler.
Rog, IIRC the Tee Dees and the 05 R/C use the same plastic part,
the Medallion is different with the NVA going through the (plastic)
venturi.
Dave
Regarding the non-SPI, I think it is also there to not interfere with the running at low throttle settings. On the other hand the Norvel engines have plenty of SPI and throttle just fine. I guess practical testing is the only way to really find out.
The Norvel carbies are oval were they fit into the crankcase, so would be rather bothersome to adapt, but the AP wasp has a round spigot carby and maybe a better opption. A VA carby can be fitted but the threads are a loose fit, VA is threaded ME 7/32-32" and the TD is 1/4-32". I have a medalion with a CNC aluminium carb bodyfitted and the VA carby can be locked in the threads ok , but a plastic carb body may not hold.
Stewart
There are 3 differences I could see:
1- There is a little ridge on the .050 carb body molding to keep the muffler from rotating
2- The ports are wider on the .050 cylinder I had suspected that as I was looking at it when I 1st got it. Today, I put a caliper to both the .050 and the .051 and the measurements are:
- .051 about 0.194 inch wide
- .050 about .210 inch wide
3 - This 3rd difference only appeared after viewing the picture: It appears the port timing is slightly different on the 050 as well. The port does not go as deep in the cylinder as the ,051 Cylinder port does. See Pitcure
I guess they did that to make-up for the lack of SPI / Muffler and keep the power as a normal Tee Dee. I have not run mine yet but I beleive Mr. Cox posted some pretty stout numbers for his.
-François
Bob,
Thanks for the offer but that will not be necessary. I have all the engines here but all are new from my collection; hence me not wanting to run then. However, it seems as if the question has been answered in subsequent posts. Thanks again.
Rog,
The carb bodies of Medallion and TD are different but the carb assembly will screw into the TD carb body.
Dave,
Thanks and the Tarno carb was essentially a Cox spin-off so the OEM carb should work well.
Mr Cox,
Correct, some carb bodies have a “boss” to prevent muffler rotation. Both versions are interchangeable.
François,
Yes, the carbs will screw in and the 2 engines sport a few minor differences. The gist of the question was whether the setup will actually work and it seems the answer is “yes”.
Cheers
Bernie
I hope it runs well with some Cylinder / Piston combos you (Bernie) sell as finding a new original .050 setup as a replacement in case something happens to mine would be next to impossible.
Bernie
Bernie
www.coxinternational.ca
That aside, a competitor/colleague andus shared the lot and I suspect that you will see the carbs listed in his eBay store before my return.
Bernie
I do have to say that moving to the US in the 80's considerably lowered my hobby shop bills. No longer being ripped-off by UDISCO (Remember their monopoly on the hobby supplies distribution in Quebec at the time? ) made for a much better hobby shop experience.
When I lived in Quebec, I used to buy everything mail order from the US at places like Towers and America's Hobby Center in NY. Even after the currency exchange (about 25% at the time) + shipping and even the occasional import duties, the mail order stuff was less than half of my LHS prices (He was buying a lot from UDISCO)
EDIT: Just looked it up: They are still around, and still overpriced..
François
I had two but for some reason, they didn't work all that well on my TDs. Well, no wonder, no adjustable airbleed. I added the feature and it helped but still not perfect. From there, I messed with the throttles themselves and now I have a pile of mangled parts.
If you DO put Cox throttles together, do all a favour and put the air bleed screw ON THE SIDE, like is logical for adjusting on the fly. Otherwise, you have to stop the engine, tweak, start, stop, tweak, start, stop, tweak, start,,,,, every bloody time you go flying. Geez, how could they have put that screw on the top and not realized how bleeding inconvenient it was. If the bodies are already drilled and taped, just add the same on the side, what's already there won't interfere. Rant over, time for more meds.
Anyway, here's a tip. Use an adapter to take turbo plugs. Very useful in playing with heat ranges and brands to get good throttling. Also, sometimes, you run out of air bleed adjustment range. If you can't get the idle lean enough, ADD a few head gaskets. You'll loose a few RPMs but a reliable idle is the result. Use more nitro.
Don't use a stock, head thingy, adapter that uses a standard plug unless you can tolerate a loss of 1.5K.
Oh yes, Udisco. A rumour I heard from a fellow at the World Scale Champs in Ottawa. There was a Canadian made radio at the time that had many of the features as a first that our radios use today. And it was priced competitively and sold well. Apparently the guy got a major order and committed to a huge investment in parts and manpower. At a crucial moment, that huge order was canceled. From there, the guy offered kits to build your own to use up all the parts and then went bankrupt. NASTY business. I built one of the kits and it was all good stuff. But my Rx had a bad solder joint, (done by me) or something and all I got out of the thing was four very nice servos.
A few other thing to consider if there are plans of reintroducing the 05RC:
- the muffler is too loose. I have made mine tighter so that it seals better against the cylinder. I have not had any heating problems with that modificating, but it still vibrates like crazy at full throttle and wears the little plastic guide etc. I have also had the hole cylinder come loose in the air.
- the main needle needs a locking mechanism, the o-ring is not tight enough to keep the setting. Mine rotates out during running, due to vibrations, until the engine runs richer and the revs go down.
- the engine mounting screws cannot be reached without undoing the whole muffler and cylinder assembly. Not only annoying but there is also a risk of getting dirt into the engine if one just wants to tighten the bolt down screws.
Apart from that it has great potential and a more pleasing sound than the rather annoying sure starts, for instance.
Dave
Here is a link to the patent from August 1972:
http://patft.uspto.gov/netacgi/nph-P...&RS=PN/3784174