Bought a few of these off Ebay the other day and I actually have one of the red tanks kicking around someplace. Was wondering (1) if the narrow slot exhaust ports inhibit performance and (2) whether these engines are good performers on their own or simply a source of spare parts.

Cent13

The narrow slot exhaust doesn't inhibit performance in any way, but it does make the engine a bit quieter (not much though).

Cox .049's are great performers - almost ALL Cox .049's. Success depends on just which plane you're putting them on, which prop you use and how good you can fly. They're tiny little engines with tiny power, but I've got an original 1950's era Cox TD .049 powering a 78" Gentle Lady glider to about 500-600 feet altitude every time I take her out (which is a couple weekends a month, all year long).

Cox had them with an exhaust-mounted throttle unit for awhile, don't know whether they still do though. The throttle engines will fly nearly anything with a wingspan up to about 30", assuming it's built decently light.

Yeah, they're pretty good engines. Lots of possibilities.

Dave

Cent,

if they are the last of the Cox offerings, i.e. from surestarts with the cast crankcase then you will find the crank is a sloppy fit in the bush. According to Dan Sitter these crankcases are Chinese made, the earlier Dragonfly cast crankcases were a better fit although I can't remember where he said they were made. Dan sells or sold the original c/cases on ebay as coxmania. So if you bought em from coxmania they should be good.

Luke.

In regards to the sloppy fit of these DC crank cases, I believe this will allow higher RPM with a balanced prop. LM Cox did this with the Killer Bee crank cases. They called this a "relieved" crank case for higher RPM. It is designed to have less parasitic drag on the crank shaft.

Sorry for the late post. All I know about the cast crankcase Cox engines is what I read. Estes thought they could reduce unit manufacturing costs with diecast crankcases but the quality control went so far out the window that they returned to fully machined billet versions. They maybe OK maybe not. At what they are selling for they are indeed worth the parts less the crankcase.

Bill

As othere have said. The early cases were made by Cox in the late 70's/early 80's for the RC Bee and maybe one or two others. Then(in my understanding anyway) during the mid 90's they expermented again with a US manufacturer, but production costs were too expensive, ect. They made a relativly small production run of these in China( I believe from the same people they used with some of their plastic models over there) around 1996 or 1998.