Cox RR-! & Scientific

Combining thoughts from two previous threads, did any of you match up the Cox RR-1 (gold case & Knurled blue tank rear SHAFT valve .049) to the Scientific "Logs"?

RR-1's were rare even when they were (briefly) made in the late 50's but were head and shoulders above the rest in useable power. I have one now but didn't back then. If any of you have them or any parts, one of the other threads says that one is currently bid at $347 on E-bay. Check your old engine boxes.

They were stunt tank equipped and handle corners well, although you had to tighen the tank attach bolts every few flights for good runs.
That problem still exists. Mine are a bit thirsty for an .049 but the one I use happily turns a TF 6/3 18,000 plus static on 5%/20% sig fuel. Unloads like mad in the air and the 5% fuel doesn't eat the bloody expensive Cox glow heads.

Any other war stories out there?

I have an RR-1 that I have owned since about 1959. Won the first contest I every entered,,,, a tethered car race, 72 MPH, a track record.

Took 2nd in the Nats with it, in Class II mouse, running against TeeDee's.

A great engine. I kept it in prime shape with new TeeDee piston & sleeve.

Only $367 ?? Too cheap. Cox should have never quit making it.

I was the first in KC to run the RR-1. Had them on Combat Kittens. The boys were still trying to learn to loop. Didn't need to with that combo. They were out running TeeDee's on custom ships with bladders. I also have left hand units for the engines. Don't ask as they are not for sell. DOC

Man, that brings back memories. I had my RR-1 on a couple control liners and on an RC 1/2A Skylark by Goldberg. Definitely more power than anything else I had in that size. And it didn't start up and run backwards. Have a couple friends who have trouble believing that Cox made a rear rotary valve engine that looked like one of their reedys.
Got stolen when somebody broke into the clubhouse at Wheelus AFB. Didn't really take too much, but this was the thing I missed the most.

I only had one Scientific "log", an L-19 Birdog. I had a Babe Bee on it, but don't recall ever flying it, or what happened to it. 6th grade. Later, I got an RR-1, and the only model I recall having it on was a Top Flite Piper Cub, the 27" span all sheet CL/FF combo kit. My first one taught me to fly. It was yellow. My second one had the RR-1 and was red. I don't know if I added more ribs, spars, or what, but I did cover the bottom side of the wing with silkspan, and it flew pretty zippy...looped fine. Also don't recall what happened to it, or the RR-1. Steve

Additional info on RR-1's if your checking your old engine box. A friend who is great on this stuff says that toward the end of production some were made WITHOUT the gold and blue anodizing. These still had the knurled tank, however. He tell's me they ran just as well as the earlier one's and are as rare as albino hen's teeth!

Jeff,

The first series RR-1 was made with a plain unanodized crankcase but with the blue tank. The second series RR-1 is the more common yellow and blue. I have NEVER seen an all plain RR-1 nor have I heard that they were made like that. I would like to know the source of this info.

Tim

That came from a good friend and engine nut who, like me, is old enough to have been there. I'm not saying you aren't right but over the years my friend has had an uncanny accuracy on stuff like this.

A bunch of us have breakfast together every saturday and I'll mention your doubts to him (he doesn't have a computor). I'll bet he finds something in documentation, one way or the other.

In any case, it make's for an interesting discussion!

Take care,

Back in the late 50' /early '60's we never bothered to measure venturis, but this talk gave me a whim to do some now. Of course these numbers come from my basement, not eh world population.

Babe Bee .057
Black Widow .080
RR-1 .100
TeeDee .147 (smallest I could find, probably bored out).

I didn't find a Golden Bee or Super Bee.

For those of you who don't recall, the Super Bee was Babe Bee with a TeeDee cylinder. It was used on the plastic P-40. Apparently
'cause the plane won't fly wid a Babe Bee. When this was discovered, all BB's in our 'hood very quickly became SB's. I don't think anybody ever looked to see if the Super Bee venturi was also enlarged ( to .080" ? ).

Conclusion: rotary valve has better timing and better suction than a reed, hence bigger venturi, more air, more oxygen, more power, more speed, more SALES.

I have almost enough parts to build one. All I need is a backplate. I think I should be able to modify a BB tank back to work.

Yes, just drill out the back with a 1/8" bit If you use a early backplate with the smaller air flow taper, its the same as a RR-1 only diff is the vents on top are drilled.

Paul: I may be wrong, but I don't think rotary valve Cox engines ever came close to outselling their reeds.

That said, the Medallion .049 still is a fine choice for sport/mild stunt 1/2A designs. As is the Fox, although it is a harder find, these days.