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.

The real QRC would have just had a muffler. No R/C control just was referred to as Quiet RC for 2 channel flight.

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.

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 .

Looks like a hot little engine.

Anodizing looks good, the exhaust ports looks to be carefully positioned, zero drag driveplate (with thrust washer?). For some reason this engine reminds me of something offered by Leo Squiers (Stoneway Group), the site is no longer up and I don't think I have many pictures saved of his work.

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"

looks like the tank has been anodizes maybe? i cold be wrong

commando*72 wrote:I bought this engine from a fellow who said it is a Cox QRC, but I have never seen a QRC with a red tank, red crankcase, and red spinner. The glow head has only two lower cooling fins, and is knurled around the center crown, like the late model high-performance head on the Killer Bee and Venom engines.

Can someone help me put a reliable name on this engine? Is it a QRC? Suggestions appreciated.

Some folks mix parts, QRC tank and Venom case.

Yes, I have done my share of custom Cox engines:

Like this "Apple Bee" engine I custom built: (Red Apple tank / Golden delicious crankcase)
HD crank, 5cc tank, throttle ring, no SPI cylinder/piston, Nitrile coated starter spring, anodized parts from our good suppliers.



And another custom-built engine (Black Widow version):
Witha Kustom Kraftsmanship needle valve and back plate, Kustom Kraftsmanship timing shim between the crankcase and the cylinder (brass shim). And as usual anodized parts from our good parts suppliers.


And I have not included all of the Kustom Kraftsmanship engines that I have purchased years ago that they customized.

Hey Mike That tank on the BW looks to bee a Matt finish ? You get that from suppliers , i remember seeing it before but not the info .

getback wrote:Hey Mike That tank on the BW looks to bee a Matt finish ? You get that from suppliers , i remember seeing it before but not the info .

Yes, I got the black anodized tank from EX Model Engines Matt.

Here is a photo from Matt's website of the tank (unfortunately out of stock).



I had to do a little work on the anodizing removal to make the BW run.
The "rough" anodizing where the reed seals was not sealing too well.
So, I used 800 grit sandpaper and removed it where the reed seals.

No more problems with the engine run now.

Photo below shows the anodized surface to be removed.
I used a piece of glass for a flat/straight table to lay the 800-grit paper on.
Then carefully sanded the black anodizing off the sealing face of the tank (where the reed seals -- on the center hole).

Hello, here are the photos of my Cox QRC .049.
I never used this engine, I love its colors and its history, so for now I just enjoy seeing it in its purest form.
I know, someday someone might do it for me, or maybe I'll start it myself!!

Thanks Mike , I like it and wish he would have more done , even with alittle work to finish it to run . Nice looking QRC Mauricio

getback wrote:Thanks Mike , I like it and wish he would have more done , even with  alittle work to finish it to run . Nice looking QRC Mauricio

I like the rougher finish. I think they would look even better on the cast crankcases?
With the rougher look on the tank and the cast crankcases they would look really antique looking?
Making it look like the tanks were cast steel mounted on a cast crankcase?

Like to see what the other colors (red, blue, yellow, green, etc.) in the rough finish would look like?

Mike Mac

commando*72 wrote:I bought this engine from a fellow who said it is a Cox QRC, but I have never seen a QRC with a red tank, red crankcase, and red spinner. The glow head has only two lower cooling fins, and is knurled around the center crown, like the late model high-performance head on the Killer Bee and Venom engines.

Can someone help me put a reliable name on this engine? Is it a QRC? Suggestions appreciated.

no qrc this is a Venom engine the real deal look for number 7 on the cylinder plus this cylinder has two bypas plus two boost port large exaust just like the kiler bee plus the back plate ventury mutch larger like the black widow it must have a berilium coper reed valve super thin valve and no screen mesh filter for max rpm this is a performance engines just mising its original head Congratulations you have found a treasure in the chess

I learn that there are 3 ways of anodizing aluminum. First one use chromic acid, second one use sulphuric acid and third one is also use sulphuric acid but in different temperature and amperes. Third one is called as hard anodizing and thicker and porous surface.

https://www.silcotek.com/semi-coating-blog/tips-on-coating-and-preventing-anodized-aluminum-contamination

sosam117 wrote:

getback wrote:Hey Mike That tank on the BW looks to bee a Matt finish ? You get that from suppliers , i remember seeing it before but not the info .

Yes, I got the black anodized tank from EX Model Engines Matt.

Here is a photo from Matt's website of the tank (unfortunately out of stock).



I had to do a little work on the anodizing removal to make the BW run.
The "rough" anodizing where the reed seals was not sealing too well.
So, I used 800 grit sandpaper and removed it where the reed seals.

No more problems with the engine run now.

Photo below shows the anodized surface to be removed.
I used a piece of glass for a flat/straight table to lay the 800-grit paper on.
Then carefully sanded the black anodizing off the sealing face of the tank (where the reed seals -- on the center hole).

this anodisation look ruf I prefer to do it thinner semi translucent fredvon4 Good link I will read carefully memorize as much as possible