hogflyer

Thanks to a buddy in Michigan, I'm now the proud owner of a Cox TD .09 RC. From what I can tell, this engine is never been run, or if it has, only a couple of times. Have some questions about it since this engine is virgin territory for me, but for free and just pay the postage I couldn't pass it up, especially after I saw a hobby shop price on the net, I'm guessing from a few years ago, showing it at $110.00 [X(]

What fuel should it use? I'm guessing at least 25% like a TD .051.

What prop and fuel tank?

What RPM should it turn?

What size plane. I'm think something like a Mach None or Pacer. Or would it do better on a DNU scaled up 10% - 15%?

How close is the power output compared to a Norvel .074?

Does it throttle reliably?

It currently has a standard RC plug in it, appears to be and RC Short. Is this stock, or an after market head?

Hogflyer

WINANS

Great power, good throttling. In my humble opinion - more than is necessary for a 1/2-A Pacer or Mach None. I built several Mach None's and I felt they were perfect on .049 (.061). Keep them light and they fly wonderfully.

7x4 props are great on the .09

Scott

Jim Thomerson

TD 09's run fine on 10% Sig Champion fuel 20% 50/50 oil. If you can find a high compression head that should make it run better. Cox 7 x 3.5 is the best prop, APC 7 x3 is pretty good. Turn it loose at around 15,000. The TD 09 is really a small light 15, not an oversize 049.

flyinrog

My Feedback: (1)

I have one of those in the .05 size, apparently that engine type (throttle/muffler) was only made for 1 or 2 years.....Rog

hogflyer

Thanks for the replies everyone. I'm now in the quandary to either put the engine on a shelf due to it's rarity, or fly it - I think my HOB ME-109 may be a good match for it.

Hogflyer

dennis

My Feedback: (90)

Your HOB plane will not be a good match for this motor. It's much too big and more motor then the plane can use. If you really need power for this plane thenb find a Norvel 074 and use that. Your TD09 will make mincemeat out of it.
Dennis

Sneasle

Idk, It might work well on that kit. I put a la.15 in my stang and it fit pretty well. Granted, It was difficult initially because I built the plane before i bought the motor, but if you have the motor before hand you can make the modifications as you build.

Be careful, I had some fuel tank height issues with mine since the tank was inverted that caused the engine to flood, but it flew great before the engine flooded.

rrragmanliam

My Feedback: (1)

HF,
I kind of agree with Dennis here. Lot's of guys have crammed in .15 size engines in the 1/12 scale HOB planes for combat, it requires extensive modification, but they are some fast planes.The TD .09 RC is not as powerfull as the regular .09TD. The power is lost with in the head design. The muffler is nice though ( have you ever heard an unmuffled .09TD run? It's unbelievably LOUD!!) If you have the box and papers it might be worth saving.

Darren

hogflyer

Unfortunately I don't have the box or paper work. I'm also curious if the head with the RC short plug is factory, or should this have a glow head like my Medallion .09? I'm not really too big into collecting engines since they where made to be flown, so I'll debate that for a while.

I've also flown the HOB P-51 with .15 power (and other Quarter Midget racers)- it's a rocket and a blast, so I wouldn't have any qualms of powering it with a .15 size engine. That's why I'm thinking the .09 may be nice - not overly over powered, yet a lot lighter than even an OS .10 in the nose.

Hogflyer

SGC

Hogflyer,
I think it should have an 09 TD head, yours seems to be fitted with an 074 QueenBee head, if you cant locate the Cox short plug to suit try a Fireball Hot short plug. Im with you on collecting versas useing , you can allways clean it up after its worn out , then put it in a case.
Stewart

Silvaire

My Feedback: (50)

The head with the short plug on your Cox Tee Dee 09 R/C is correct and original for this engine. Both the 09 RC and Queen Bee .074 have the same head - Cox part # 3703. The plug itelf is also has the same part number for both of these engines. A standard short RC plug may also work, but I do not know this for sure.

Although both the Tee Dee 09 R/C and standard Tee Dee .09 appear nearly the same (other than the obvious carb and muffler), the ONLY part numbers that is directly interchangable (according to the parts list supplied with each engine) is the prop screw and spinner! Many (or most?) of the parts within the crankcase assembly would actually be interchangable. However (again, according to the parts list supplied with the engine), these parts were sold ONLY as an assembly when the 09 R/C was offered - and each version of .09 had different crankcase assemblies.

Here are the weights of the Tee Dee 09 R/C and some other engines to compare to. These are actual weights done by me with a scale with .05 oz. resolution.

Cox TD 09 R/C 3.85 oz. (incuding muffler and plug)
Cox TD .09 2.80 oz. (no muffler)
Cox Queen Bee .074 3.85 oz. (incuding muffler and plug) (Yes, it weighs the same as the TD 09 R/C.)
OS Max 10 FP 5.65 oz. (including large cast muffler and plug)

How do these compare as far as performance? Although I will admit that I have a fetish for COLLECTING little Cox engines, of the engines mentioned above, I have only actually USED the OS 10!

Arlen


EDIT - Late additions to this post:

AP 09 Hornet 5.60 oz. (including muffer and plug)
Cox Medallion .09 3.00 oz. (last version made with ring muffler/throttle)
Norvel .074 2.85 oz. (including muffler and plug)

To me, the big surprises here are how light the Cox engines are and how heavy the AP 09 is. (The AP 09 is a ball bearing engine though, which adds a bit to the weight.)

I think that if noise is not an issue, a standard TD .09 with a bushed down venturi and a throttle ring from a Medallion .09 R/C (what might be best described as an .09 version of a "Dickey Bird" TD .049) would be a contender for best power to weight in a throttled engine of this general dispacement size.

Lastly, I think that the Cox TD 09 R/C might possibly be close to the Norvel .074 in regards to its power to weight ratio.

Jim Thomerson

I have a nice used FP 10 I bought at a swap meet. Have only run it on the bench without muffler. It is in the same league as my standard TD 09's.

mylamo

My Feedback: (1)

Jim: You are right about the O.S. muffler. If you
open it up all you can and use a 7X4 it does very
well. I bet the Cox .09 with a five gallon muffler
is louder than an O.S. .10 with no muffler, however
in a race , my money is on the TD.
Ralph

Jim Thomerson

Guys in the Illinois area near St. Louis were flying 09 -10 size pylon. The RC TD 09's and FP 10's. The engine guru I knew was running the TD's. I supposed he knew what he was doing.