What Cox engine is this?

First:
Q = Quiet
RC = Throttle of some sort

Your engine has neither

What you have is a cool . 049 that needs some further investigation

Not from Matt or Bernie...because it has a metal back plate

But the red Crank case and tank are probably from Matt or Bernie

To know is just a cool looking typical Bee or a hot rod

Cylinder porting, looks like High Compression head
Back plate venturi opening size I think (and will be corrected if I am wrong) the standard bee has .063 hole and hot rods have something bigger with diminishing returns above .082

Here are all the current specialty Cox International Bernie Creations with serial numbers...I collect #55 for my birth year

The was an all Red one called the .049 Xtreme

I don't recall any QRC's with a red crankcase, although they may have existed. The QRC did not come with throttle. "Q" was for quiet, it was only muffled, but the factory retail engine did not have throttle. First retail throttled reedie was the R/C Bee in 1976, but 3rd party unmuffled rotating throttle sleeves were available in the early 1970's through outfits like Ace R/C. Some used these to retrofit engines for RC throttle use.

It was intended for those who needed a muffled engine some 40 years ago, when most RC proportional flying was done on 2 channels. Radio flight packs were heavier then, except for special mini systems like Cannon that were more expensive, beyond an entry level RC hobbyist's budget. Thus, much flying was done unthrottled. The Airtronics Q-Tee and S-Tee by Lee Renaud are such kits available back then to make use of the QRC.

Being unthrottled saved the weight of another servo and lessened current drain allowing use of a smaller and lighter nominal 4 cell 250 mAH nicad pack.

There wasn't much difference speed wise under power or in power off glide of a half-A plane with a roughly 36" wingspan powered by a .049 Golden Bee or Babe Bee reedie. Integral tank gave a couple minutes flight, so throttle was a luxury.

Our newer and lighter radio systems and smaller more powerful servos have made throttle more practical.

Following is from Wikipedia: Cox model engine

Wikipedia wrote:o 1966 QZ (Cat#450 - manufactured 1966-1996)

QZ stands for Quiet Zone. It is a Babe Bee with a muffler, twin bypass port cylinder with no sub piston induction and a high compression (#1702) glow head. An attempt to regain the power loss caused by the muffler. Very similar to the later QRC engine which reportedly worked better. Cox also sold the muffler, cylinder and high comp. glow head components of the QZ as a Muffler Conversion Kit (Cat#495) for $2.98.

o 1976 QRC (Cat#450-1 - manufactured 1976-1996)

The QRC was a modified Babe Bee engine that had a muffler and larger (8cc) fuel tank. In the 1970s noise became an issue and the Cox engineers discovered that when adding a muffler the engine would lose significant power. This problem was alleviated by installing a cylinder with no sub piston induction.[14] The engine was designed for power launching Radio Controlled Gliders and had a red tank with a blue spinner.

commando*72, seems that you may have a reasonably high performance engine. For one, it comes with the higher compression Tee Dee head. Check to see if you have SPI (sub-port injection), there will be a gap between the piston skirt and bottom edge of the cylinder exhaust port when piston is at top dead center. Look into the sides of the exhaust ports under a good light. If it has dual bypass ports visible on each side with the piston down and SPI, then I'd say it probably has at least the higher performance of a Black Widow.

If it has no SPI and dual ports, then you have performance equivalent to the QZ and QRC. It will still have higher performance than the earlier stock Babe Bee engines.

You may have a custom high performance engine on your hands that is not an original Cox factory product engine. It certainly has a very nice anodized finish. If color is reasonably true in the photographs, appears to be a slightly different shade than Cox anodizing.

Back in the late 1970's and early 1980's, I flew a Sterling 36" span Minnie Mambo Cabin powered by an RC Bee engine, which was basically a throttled QRC (QRC was unthrottled) with cast crankcase, larger capacity tank and internal clunk for aerobatics. It was a good engine, more powerful than a Babe Bee.

Jason_WI wrote:I have been emailing Don. The engine has a HD crank and a #4 cylinder. The only thing to change is to get a non vented black widow back plate for true stunt performance .

yep, it has all the good stuff, verify the tank is the larger diameter (black widow) air tube, replace the back-plate, check the ball socket
and you're good to go!

Anyhow, I found this question entertaining as I work on Cox engines Most day's being retired. And have done so for what seem like a long time.
Anyhow, I would suspect that the owner, as the engine looks to be in very nice condition, possibly changed out to one of the red crankcases, that were anodized, other than done by Cox.
I checked them out as I do My own Anodizing, and it was basically a tumbler then into the anodixing tank. As I am not able to to really "See" The engine, I am unable to know for sure.
Ass this has a nice 1702 Glow head, that I hope is good. So who You got this engine from or the person right before New What He Was doing, down to the red spinner that are available today,
are came on a couple different model's. I would get a good debuild kit and check out the inside, and the cylinder.Overall a Nice Engine.
Jim "P"