Ragwing

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Hey guys,

I'm really jazzed because I just got this Space Bug on eBay for $18, spur of the moment. I guess I'm startin a collection . What is it worth? Was it a good runner?

Thanks!

Derek

William Robison

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Derek:

From the middle 50s to early 1960 there were three hot Cox engines, there were still some who liked the Atwoods and Holland Hornets, but these three Coxes ruled 1/2A.

The three were the Space Bug which you have, the Thermal Hopper, which is the same as yours except without a tank, and the Space Hopper. The Space Hopper was the same as the Thermal Hopper other than being modified for beam mounting instead of the radial mount.

You got a good deal.

The Space Hopper is the rarest, having the lowest production numbers. The Thermal Hopper is the second most desired, it was used mostly in contest free flight, lighter than the Space Bug since it didn't have the fuel tank.

Actually, the truly rarest Cox of those days is the ball bearing version of the Space Hopper. Very few made.

Yours is still fairly rare, it went out of production when the Baby Bee and Golden Bee were introduced. The Golden Bee was similar power, while the Baby Bee was a "Starter" engine. The Baby Bee had a single bypass port in the cylinder, the others all had double bypass ports.

And I've probably told you more than you wanted to know. Sorry.

Bill.

Ragwing

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Bill,

Not at all-tell me more. These little engines are so intriguing, I like the look of the Space hopper and Thermal Hopper better, but they are all neat engines. I've heard that the cylinders on these engines were different, at least externally, from the later engines. Is that true? I guess I'll be able to figure some of this stuff when I get my hands on it.

Thank you,

Derek

Tim Wiltse-RCU

Derek,

Nice Thermal Hopper you got yourself there!!! Of all the rare Cox factory pieces the rarest has to be the Strato Bug and the drum rotor Olympic .15.



Later,
Tim

DICKEYBIRD

It's a Space Bug like Wm. said....here's a Thermal Hopper:

Tim Wiltse-RCU

That is what I wasing thinking but my fingers typed Thermal Hopper because I was thinking about Bill's message!!!

Later,
Tim

William Robison

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Derek:

Few things in model engines are more complex than keeping track of the variations on Cox cylinder barrels.

To begin, there are three different external shapes. The original, as on your engine and the picture Dickeybird posted, are the same smaller diameter from the lower flange to the bottom fin. Then there is the version with the diameter increased to the size of the mounting flange around the exhaust port, still having a smaller diameter area between the flange and the area around the port. And the third shape with no decreased diameter between the seat and the bottom fin.

And some have flats milled at the top of the barrel for a wrench to remove and install the cylinder.

The exhaust ports can be open, as yours is, or two slits instead of the open pair.

Thus far we have only covered the external appearance, and have 12 possible different barrels. Now we go inside.

To begin, there can be either one or two bypass ports. The "Starter" or "Beginner" engines had a single bypass to limit the power, but most engines had two. But whether one or two ports, they could be milled in one pass, two passes, or three. The milling difference was obvious when the barrel was off, but could not be seen from the outside. The single or double porting could be seen from the outside if it had open exhaust ports, though.

Then we add the bore itself, either 0.401" for the 0.049 or 0.410 for the 0.051. Usually the carb mount on the TeeDee engines was black for the 0.049 and red for the 0.051, but sometimes the colors didn't match. And the reed 05 engines had nothing to differentiate them from the 0.049s.

Then came the latest variations. First was the port timing. All the earlier barrels had "Sub Port Induction," when you moved the piston to TDC there was a gap exposed in the exhaust port, the piston skirt rose to expose a gap allowing a little more fresh air in, the main mixture could be set a little rich, ending up with a bit more power. But it could also let the engine pull exhaust gases back in, and in a tightly cowled installation this was a problem. So there is another version with the exhaust ports raised to prevent the SPI.

The final variation is hard to check, it is the bore shape itself. There's the old standard straight bore, and some late barrels with a tapered bore in the manner of ABC engines. This is intended to have a straight bore when theengine warms up. Seems to work, but these barrels are rare.

Almost 150 possible variations, but I can only be sure of having seen some 25 or so.

Not even mentioned to this point, but some barrels have a number stamped on the side below the exhaust port. These numbers are supposed to identify the variation, but I've seen the same number on different barrels, and identical barrels with different numbers.

One thing that makes it even worse. I have three NIB Coxes, supposedly the same engine, with the same production date stamped on the cardboard in the box, and they have three different cylinder barrels.

You can understand how pleased I was when I finally got a true matching pair of TeeDee 05 RC engines.

Bill.

William Robison

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Derek:

Here are pictures of what I call, in order, the B1, skinny, barrel, the B2, with the smaller diameter under the exhaust port, and B3, the fat one. The fourth picture is what I term the B3A, the fat barrel with the slit exhaust ports.

Bill.

William Robison

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And here are the bypass ports. These three pictures were taken by Dickeybird (I think) so give him thanks for them. I refer to them as P1, P2, andP3. So a fat barrel with two flute ports would be a "B3P2" barrel.

Also note the "P1" barrel shown has the "Slit" exhaust ports.

Also attached is a rough brawing with dimensiions of SPI and Non-SPI port locations. And I have seen both "Slit" and 'Open" ports positioned for both SPI and Non-SPI.

Bill.

gcb

Ragwing,
The Space Bug is a control line engine and is the first 1/2A engine that Cox Produced. The pickup inside the tank is set in the outside rear center. If you use it for other than CL you will use only half the tank unless you mount it sideways (needle down). It was THE most powerful .049 when it came out.
The Thermal Hopper followed shortly and aced the Space Bug out because it was more versatile. The TH was harder to mount unless you used the "cage" that was available or created something equivalent. The TH quickly started setting half A records in FF and CL Speed.
I THINK the Space Hopper introduced a slightly different needle in the needle valve assembly. This was carried over to the TD.
Pardon the ramblings.

George

Ragwing

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William et al,

Thanks for the detailed information, I have bookmarked this thread and I'll use it as a reference. Great information on cylinders!

I've seen Space Bugs with plastic or deralin tanks, was this a modification for FF? Looks like I'll have to build a classic C/L plane to mount it on, thought it would probably see less abuse in a R/C assist FF plane. Any suggestions? What fits the era?

Thanks!

Derek

William Robison

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Derek:

I have to come back in after reading through this thread again.

I have what is truly the rarest of all Coxes, Thee were only three made that I know of. It was an experiment that didn't work, there was no power gain, and it was a lot more trouble to run than the ordinary versions.

Your eyes are indeed telling you the truth - a twin carb Cox.

Bill.

Tim Wiltse-RCU

Bill,


You better make that 4 because I can do that too with a Space Hopper backplate


Later,
Tim

William Robison

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Tim:

Haw!

I wondered how long it would take to get busted on that one!

Bill.

Tim Wiltse-RCU

Bill,


Step away from the computer and take your meds

LAter,
Tim

William Robison

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Tim:

It was posted as a joke, of course. But it was worth a try.

After all, how many people around here do you think have ever seen a Space Hopper?

Bill.

Tim Wiltse-RCU

Good point!!!


Later,
Tim

ajcoholic

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I had all the old cox's in my collection: space bug and the hop up kit, red, white, blue and yellow space bug Jr's, strato bug (red tank, yellow tank does exists but good luck to find one) numerous thermal hoppers with single and twin carbs and the cage mounts, yellow and silver body RR-1's, the space hopper (had a few) and then the 09 medallian and TD, and all the TD 15 variants, the 010, 020, 049, 051 and 09 tds as well as all the medallians, and the 15 sportsmans and one lowly olympic.

I collected most over a few years time, and none are really rare IMO but the STrato bug... it took me three years of constant searching.

Three years ago, at the toledo show an older MECA member was taking some cox stuff out of a box and I saw it - the strato bug! I ran over and didnt even look at the marked price, said "i'll take it!" and then saw it was only $40.

Ahh, memories. SOme day I will start collecting again. WHen I have lots of $$ to burn that is

AJC

ZAGNUT

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sounds to me like you need to hit that hardass boss of your's up for a raise

dave

gcb

Derek,
The ones with the plastic tank are the Space Bug Junior. They were marketed as a beginner's engine. The cylinder has a single bypass. I think the plug has lower compression also (too lazy to check). They are easy to start and have great fuel draw. My first NEW engine was a Space Bug Jr. with the natural nylon tank.
Both the Space Bug and the Space Bug Junior (and TH without cage) were somewhat a pain to mount because you must drill a hole in the firewall and provide an air path to the intake. This makes it hard to choke in most installations.

George

jessiej

I really enjoyed the Thermal Hoppers. Still have a couple of them-the rest flew off to parts unknown. About the time the Babe Bee came out I fell under the evil Cox Curse and have had very little sucess with reedies since[&o]

Silvaire

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This has been an informative thread on vintage Cox .049 engines. The Strato Bug has been mentioned a couple times, and this is an engine that I have never seen. Dose anyone have a picture of one of these engines that they could post??

Also, regarding the number of cylinder designs that Cox used over the years:

When I was at the AMA convention in Ontario California this winter, I met a vendor (who is also a Cox collector) who had managed to gain access to and research the Cox archives when Cox was located in Aneheim. He told me that had been able to document 65 different .049 cylinder variations that Cox had actually produced up to that time. I cannot remember this mans name (so perhaps I shouldn't be telling this story here?), but he also sells on ebay under the name Coxmania.

ajcoholic

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That would be Dan Sitter (Coxmania).

He has been selling parts for a lot longer than ebay has been around too. Only now his prices are higher

AJC

Tim Wiltse-RCU

55' Strato Bug.....

Silvaire

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Thanks Tim, I'll keep my eyes open at the swap meets...[:-]

Arlen