Originally Posted by
ffkiwi
The mid to late 50s Cox engines you refer to were DRUM valve-not rear disc-known as the RR-1. Cox's terminology was incorrect. The drum was much smaller in diameter (the major rotating mass)-and machined from steel-so the drive flange which engaged the crankpin could be a lot thinner than a disc valve setup-about 1/32" or so-and the drive was via a hole-but a radial slot from the outer edge also works (and is less stringent on alignment.
Chris, would that term "rotary" versus "drum" be more a matter of semantics? Rotary means rotational, and the 1950's were the developing grounds for much more powerful engines than the 1930's and 40's? Did not the current implied meaning of rotary valve develop through de facto buzz words for high performance "racing" versions of glow engines?
Naturally they (the RR-1) were more expensive than the reed valve coxes to produce-and presumably that was why Cox dropped them. A pity really-as I would take an RR-1 over a Babe Bee any day.
I haven't found an engine review, which would help me to compare the RR-1 to the Tee Dee and Medallions. What is its power likened to?
Some stuff was just silly-the machined ribbed tank and thev ribbed crankcase nose for example-which was purely for appearance-but must have added significantly to the production cost.
Back in the 1950's, art deco styling was very common, for example, tube (valve) radios had their cases moulded with this type of ribbed design work. Only speculation, but could it be that Leroy Cox was experimenting to find out what sold engines? Modellers aren't given over to fashion statements but function, so as you allude to, this was a costly step that did not contribute to selling engines.
Likewise the anodised case which though it presents a nice contrast could have been left plain [though I admit the RR-1 is one of the most visually attractive Coxes made-the other IMHO is the Olympic 15]. Cox could have achieved the same visual effect simply by anodising a plain machined Bee tank bell blue...and anodising a standard reed valve case yellow for effectively the same visual effect.
Testors Corp. made a similar costly mistake when they came out with their Black Head series, replacing the Red and Blue Heads. Cast crankcases made a fashion statement but added considerable weight to the engine without significant performance gain. (Adding crank ball bearings would add weight but benefit reducing friction for increased horsepower, but this was not done.) Peter Chinn mentioned with cooling fins, helped create a denser fuel charge, (yet I wonder if he said that to be kind to the promoters). But modellers did not see it that way. Testors continued with cross scavenge technology when others were going to Schneurle porting. One could pick up a Testors Black Head on clearance for $4 or $5 US in the mid 1970's. Nobody wanted them. I bought 5. My brother bought a couple, too. Now, CL fliers use Black Head parts (piston, cylinder liner, etc.) to upgrade the Red Heads (in some cases, machining required) to make a light yet more durable Red Head.
A casual search shows them going for $300-500 USD in half decent shape. For that much money, I'll enjoy the nostalgic pictures and play with modern fast .049's..
Or .061's and .074's.
I still enjoy playing with sport .049 reedies, they provide a lot of bang for the buck.
