Little Foxes

There has been a fair amount of discussion and confusion regarding the smaller Foxes, so I thought I would offer a short course in Little Foxes. John Krickel wrote the definitive article in the old .049 newsletter.

1. In 1959 Fox designed the .07 for Comet RTFs. There were variations, but common to all seem to be the die stripping tab under the venturi, the square topped venturi, and the tank designed for side mounting the engine. The cylinders were always horizontal in the Comet planes. If you watch Ebay you’ll see these engines, nearly always with the tank vents in some screwy location as it seems no one knows the correct orientation. My picture 1 shows it correctly!

2. Comet was going under and the story goes that Duke raided the Comet factory and “repatriated” many .07s. The die stripping tab was removed, the top of the venturi was cut off at an angle, and if there was a Comet Shooting Star on the side of the engine, it was ground off, and holes were drilled in the beam mounting lugs. Presto, the Fox .07 Compact Stunt Motor of 1961. These were sold without a tank. For the first of these, the face of the Comet tank was sawn away from the body and used as a rear cover, later, a nice cast rear cover was used. My picture 2 shows this engine.

3. The last .07 was the 1965 .07 RC. This engine has “.FOX” over “07 RC” cast on the side, so shame on you if you can’t identify it; my picture 3.

4. The first .049s came out in 1962 and were sold with and without the tank ( with a bolt pattern for a vertical cylinder). You can’t tell them from the outside from the Fox .07 unless you can discern the thicker cylinder walls. These used all .07 parts except for the piston, cylinder, and glow head. The .049 has a 0.390” bore; the .07 0.460”. Take off the glowhead and measure if you’re not sure. My picture 4 shows this engine.

5. In 1964, the new improved .049 came out. This is the engine many people think is the .049 FAI. This engine was always sold with a tank, was tumble polished, has stiffening ribs on the front of the case, and “FOX 049” cast on the side in rather bold letters. Also, most had a crankshaft stud and nut instead of a screw for prop mounting. Picture 5 shows this engine.

6. Also, in 1964, the .049 FAI hit the market. It had a matte finished case (NOT POLISHED). The crankshaft was larger in diameter, reflected in the front diameter of the case. You can take off the drive washer and check the crank diameter, the stock .049 will be 0.250”, the FAI will be 0.312”. The stock venturi has a 0.156” bore, the FAI 0.188”. The FAI has “FOX” over “049” cast on the side, but in rather thin letters compared to the 1964 engine. A dead give away, is the trapezoidal shape of the exhaust ports, larger at the top than bottom. The engine also sub-piston induction where the bottom of the piston uncovers the exhaust opening at the top of the stroke. This is the engine Randall Hopkins sells. Oh yes, they have a nice turned spinner nut. This is my picture #6.

There were lots of variations I’d love to discuss, but this is already too long and I’m afraid Leonard will arrest me for felonious loquacity, so email me!

Tim Dannels and Doug Martin are running an index of all production Fox engines in the ECJ, so get it if you really want to identify Foxes!!

[photo not recovered: 07049web.jpg]

Thanks for the Fox info!

Where do I buy the Engine Collectors Journal?

I think that I need one pronto!

BIGS

" What constitutes the dignity of a craft is that it creates a fellowship, that it binds men together and fashions for them a common language. For there is but one problem - the problem of human relations."

You can contact Tim for the ECJ at:

Dannels, Tim
E-mail Address(es):
[email protected]
Personal Information:
Address:
28795 CR331
Buena Vista CO 81211
USA
Phone: 719-395-8421

Tell him you want the Fox issues #161, 162, 163, and 164. These will get you from the start (1947) through 1971. We're not sure when the next Fox issue will be out.

Thanks for the info, I knew about the Fox/Comet, but didn't know he repo'd them from Comet. I'd would of guessed they never got delivered.

Several years ago I was running a Fox on bladder pressure on a 1/2a profile Nobler I designed. the Fox really ran strong, seemed almost better then a Tee Dee....it dawned on me a couple of years later it was a 07!

Mark

P.S. Would anybody out there have a Comet 049 they want to trade some 1/2 A parts for? email me.

These Foxes are wonderful little engines, and not well appreciated (translation: tried), even among experienced flyers. The non FAI ones are as strong as Medallions. They also are robust in crashes. The price was right, too.

Fox did not market them with great enthusiasm. The money was in the larger motors.

Fox 09s and Hustler 10s were not Fox's finest moments (and some people don't care for the early 15, either). And sometimes the .07s and .049s get a similar rep, for no good reason.

All of these engines can be capable sports motors, the 1/2 ones with no effort at all. Currell

Mr Willie - thanks for a most informative post.
We became familiar with the Fox .049 while searching for powerplants for the Musciano designs. On the test stand, they were far and above anything else we tried.
We were quite successful from a standpoint of performance but not longevity. We found that after a modest number of runs (flights), the connecting rod (or its captive ball joint) would fail. I gave away most of my parts to a friend, since I decided to switch to the OK engines.
Regarding the Foxes, I still have a number of new ones, including a Comet version, that I will carefully break in. The best of them will go in my next-year's Musciano plane - whatever that turns out to be.
Or, I'll just go back to the OKs.
Bob Z.

Randall Hopkins of Paducah, KY has purchased all the Fox .049 and .07 items from Fox several years ago and he is making these available to flyers who desire one of these motors. He can be reached by phone at 270-554-3359. His email address is:

Randall Hopkins
E-mail Address(es):
[email protected]

Randall works hard to sell a fine product.

Speaking of failures (and V12 may recall this), I had a shaft run on my best Fox at this year's Musciano. I already had completed my 12 Proto Speed laps, and the engine went up about 4000K rpm, and sounded funny. A few laps later, another 4000K or so, and it sounded really funny.

Inspection at the field showed no up and down piston movement. A teardown revealed the "big" end of the conrod had broken off (it actually is the size of a BB). The prop had worked loose, but not completely so. Also, the ball joint betweeen P & C was mighty loosy goosy.

But this was abnormal service, and I have never had a failure otherwise.