Super sport 049

Hi Mark, Welcome to the forum!    The red "Killer Bee" horseshoe-backplate assembly that CEF member KariFS mentions, was available from Cox International not too long ago.





The venturi of the red Killer Bee backplate is slightly larger than a stock horseshoe-backplate.. which affords increased airflow.. which equals more power-potential.

Below images show the differences in venturi's between the red (KB type) and a stock backplate.





The original Killer Bee engine was pretty much the most powerful reed-valve engine that Cox made. You could "clone" one though.. which would haul your Super Sport with authority. You'd need the backplate assembly, a crankcase assy. (*), a Tee Dee spec. cylinder/piston/rod assy. and a high-compression glow-head. You'll also want fresh fuel of at least 25% nitro.. with a 50/50 blend of castor/synthetic oil. (don't run the engine without castor-oil in the oil mix)

(*) The original Killer Bee engines had a HD crankshaft because of their high rpm capability. If you have successful experience with R&R of Bee engine crankshafts, you might want to go that route.. but you don't have to.

Oh Wow !!!! Thanks guys for the Great Helpful information. I will definitely be looking into that. Perhaps you can help me with my fuel. I have plenty of 30% fuel with 12% synthetic oil. I was going to add 2 ounces of castor to my quart bottle of it. Do you think that will be ok ? Thanks

Sorry, but I need to recalc your numbers to my sinful SI units :

- 1 quart is 0.946 liter that has 12% oil = 0.946*0.12= 0.113 liter of synthetic oil in it.
- The combustible (nitro+methanol) content is 0.946-0.113= 0.833 liter.
- With a 22% oil content (i.e. 10% castor+12%synth) you want this combustible content to be 100%-22%=78% of the fuel. Meaning, that after the addition of castor, you will have 0.833/0.78=1.068 liter, which is 1.068-0.946=0.122 liter more than 1 quart.

- So, if you add 0.122 liter (= 4.1 oz) castor to your 1 quart fuel originally having 12% synth lube content, you will have 1.068 liter of fuel with 22% lube content, of which castor is 11.4% and synth is 10.6%. The combustible (nitro-meth) is the balance 78%. This 22% synth+castor compound should be good enough, even if I myself prefer all-castor fuels in my COX engines.

My one and only COX C/L plane was the Super Sport Trainer that I got in a rather inexplicable way in 1974 still behind the Iron Curtain..that COX plane, and a red-postage stamp backplate reedie from an abused Stuka of a high-school buddy with relatives in Germany sending him the plane that he zeroed in no time but he scavanged the engine for me, have obsessed me with COX for a lifetime.


My Super Sport trainer was powered well with the same, white horseshoe backplate engine that you have, to teach me fly C/L on a basic level, so I would not be concerned with the engine, but if you really want to ramp it up, I agree the Killer Bee backplate, a high compression TD head, or, moreover, a Kamtechnik turbo plug adaptor head will do wonders

Greenman38633 wrote:I have plenty of 30% fuel with 12% synthetic oil. I was going to add 2 ounces of castor to my quart bottle of it.  Do you think that will be ok ?

Using a spreadsheet and simple algebra, I came up with a similar result to András'. I would double your Castor oil, as calculated:

2 oz. Castor oil bumps oil up to 17.2% with 5.9% as Castor and 11.3% as synth, falling a bit shy of at least 20% oil total with half as Castor.

If you double Castor to 4 oz., then you have a 21.8% oil package with 11.1% as Castor and 10.7% as synth. This bumps your quart to 36 oz.

In general, the Cox seems to handle oil up to 25% total, also alluded to by Peter Chinn in his engine reviews. The stuff I used for my larger engines, the older non-Schneurle cross scavenged ran in the Coxes too. Just letting you know there are oil limits due to viscosity (thickness) to flow freely through the needle valve passage.

My Norvel .061 didn't like the thicker oil. May be it has finer orifice passages in its fuel metering system.

Thanks Guys so Much for the valuable information. I just purchased a modified engine for it off of a Guy on EBay. Let me see if I can post the pictures here

Having trouble posting pictures

It says 18,000 to 20,000 rpm with 5 x 3 prop and 25% nitro

We will see. Another question that I have is the control lines themselves. The planes come with short lines causing the person to have to spin around very fast to keep up with it. I was thinking about using 60 foot lines to reduce that. Do you guys see a problem with that ? I just bought a set of 60 foot stainless small diameter lines and a after market adjustable handle

I hope I am not getting ahead of myself. Any help you guys can provide would be Greatly appreciated. Thanks

The general sport .049 C/L planes fly on lines 25 to 35 feet. Reason for this is to maintain line tension, which becomes even more important during wind conditions.

They are not capable of flying on 60 foot lines.

Carl Goldberg's half-A Wizard kit claimed to fly on I believe 50 foot lines, but it had an articulated rudder that would upon loss of line tension steer the aircraft outward.

Modified hot .049 Medallions and Tee Dees use 42 foot lines, but some have used more.

The 2.5 to 3 second laps on .049 Reedies is typical, yes, a little dizzying over the 4.5 to 5 second lap speeds of the larger sport and stunt jobs.

The newer Dyneema fishing lines are inexpensive. In carrying out your own practical experiences, you'll know for sure.

If you build a profile half-A of sheet balsa construction, they are more sturdy and easily repaired during mishaps, especially if flown over grass. It could be your practice ship to get you back into flying condition.

This will help you to avoid the common one shot flights that I had when younger. The plastic ready-to-flies were made of such brittle plastic, that they shattered into pieces upon hard impact, and broke parts on less.

Another thing to consider is the drag of the lines that affects the plane's speed and stability. The larger stunt jobs have less of a problem in overcoming this, being heavier and more powerful.

I received my Super Sport in "74". My dad and I went to a school lot and got it running and it would only run around on the ground with a occasional hop into the air. He was able to get the plane a bit higher but it was flying nose high and very under powered from memory. I never tried again and it resides over my work bench. Some years back I weighed it and it was almost 3 times heavier than what I typically fly with Cox equipment. One thing I noted over the years and I've seen this on many is how the plastic wing droops and warps, this could seriously impact it's flying ability. I've seen some video of the Super Sport II flying which did bring a smile. Essentially the same plane in yellow vs purplish pink.

I had a purple version back when they first came out and a 2nd picked up about 5yrs ago.
Cool design can do a quick fix and add a TD top end with performance crank or a Killer Bee
both with a turbo plug adapters. The plane is heavy and comes with the 6x3 prop for thrust.
APC 6x3.1E 6x4.1E and 6x4 should improve thrust and speed / 35% nitro should get it moving.

Here is a purple attempt.


Jul 2, 2020
COX SUPER SPORT TRAINER

Hey Guys. Very useful information. Thanks so Much. One thing I noticed about the Super Sport is that not only is the rudder offset to the right but also the engine is offset to the right also. That should help

I’ve also read about putting a small weight under the far outside wing to help but I’m not exactly sure what the purpose is.

Greenman38633 wrote:I’ve also read about putting a small weight under the far outside wing to help but I’m not exactly sure what the purpose is.  

It helps to counteract the torque of the engine in a standard right hand turn propped engine (standard aircraft practice, viewing the prop from the pilot's view - the cockpit).

Rudder offset helps with line tension by canting the aircraft outward, but it also creates drag, especially when used with greater offset angles. the outboard wing tip weight, usually conveniently a US coin - penny is sufficient for half-A.

Larger stunt jobs may have a weight box with compartment door, where the tip weight can be adjusted.

Tip weight on R/C aircvraft have helped counter take-off engine torque in a smoother manner than increasing rudder or thrust offset, as exclaimed by one R/C warbird designer in an article I read some years ago.

The weight in the right wing is mostly to counteract the weight/drag of the lines.
...Bill

Greenman38633 wrote:Having trouble posting pictures

Admin set a minimal post count plus time as member to limit spammers from posting. You already have sufficient number of posts, photo upload posting privileges is either 3 or 5 days.

Instructions on how to post is in a thread under Introductions section on the main menu.

ncpiperpilot wrote:The weight in the right wing is mostly to counteract the weight/drag of the lines.

You're right, Bill, it is the combination of that and engine torque.

Thanks for all the fantastic information guys. It has been very helpful. Mark