Cox engine question.

On Tue, 12 Jun 2007 18:20:48 -0700, snipped-for-privacy@yahoo.com wrote in :

I don't remember any markings.

It seems to me that there is a "look" to all of the Cox engines. I had an .020 and a slew of .049s when I was a kid (circa 1965). I think I had one Black Widow, too, or a Tee Dee (?).

I just see the Baby Bee here:

On sale for $7. What a bargain!

Marty

Dunno they marked ANY of them..

They were the first people to use CNC machines big time IIRC, and a lot of stuff was machined from solid, not cast, so not easy to put a mark on the machined bits.

I have about 20 Cox .049 engines, and none of them say Cox on them. Not sure about my Teedee engines, as I don't have them readily avaialble.

Is it safe to assume that if it uses the Cox glowplug, it's a cox engine? Did any non-Cox engines use the same glow plug?

There was something called a Wenmac that looked similar

I looked at the Wenmac engines, it isn't one of those.

I found one identical on a website that has cox engines.

I just didn't know if any other companies had made identical engines to the Cox engines or not. Since mine wasn''t marked Cox, I was looking for some knowledgeable folks to help me out.

Thanks for all of the help!

The early Cox engines such as the Space Bug and Thermal Hopper had "Thimble Drome" on the lower front of the crankcase, which was cast, not machined from an extrusion. A few of the .020s and .049s with the aluminum fuel tanks had "Thimble Drome" stamped circumferentially on the tank. Except for the Cox Conquest .15, I don't think there were any other engines that made it into full production with markings actually saying "Cox."

As for their glow heads fitting other engines, Norvel and AP will thread on, but you change the compression and running suffers. However, someone (forgot his name) in the 1/2A freeflight crowd makes heads that use either Nelson or OS "turbo" plugs that work well.

If you are referencing this engine:

isn't the Babe Bee. It's the "Sure Start" engine they supply in their RTF airplanes. It lacks the intregral tank and radial mount the Babe Bees used to have. A few years ago they were clearing out these Sure Start engines for $3.99 each. I bought 4.

$3.99? Nice. Today they are $6.99. I bought about of them :). Enough .049s to last me the rest of my life, and a few left over for my kids to inherit. To bad they aren't clearing out black widows or teedees.

Anyone know if these surestart .049s can handle a 5x3 prop on a small airplane? I've ran them on the bench and they ran, but I don't know what it will do to their life expectancy. I use fuel that is about 15% castor oil and 10% synthetic oil, with about 22% nitro.

ISTR we ran em on 6x4's..

So 5x3 fine..

There is a huge huge difference between a 6x4 and 5x3. I don't know if the sure start engine has the power to take advantage of a 5.3 prop, nor do I know what it will do the life expectancy of the engine.

Shouldn't be an issue. I have always swapped out the stock jugs for either a Black Widow jug set or a Tee Dee set to get a little (very) improvement. That combo and 40% will make a clipped wing Wizard haul quiet nicely on a 5-4 prop.

As always YMMV and that was the late 70's.