Fox .07 engine. Looking for history etc.

[Robert McHam]

First I Yahooed, then I Altavista-ed and yes I even Googled and came up pretty dry.

This one I had not heard of till recently and I found Fox even made a throttled version of this cool little engine!

I am interested in anything anyone can tell me or show me regarding this engine.

I suppose I should ask Fox since they are still in business, but when I called Dumas about the plan for their Little Tomahawk they said that they sold all those related items to some company in Alabama which I tried to find, to no avail. I do hate chasing rabbits!

Production numbers, production years? Just a guess at early 1950s.

Will the glow head interchange with anything at all? 

I would ask about performance but if it were really something special in that department we would all be stumbling over them just trying to walk.

I think I will look at Mecoa and see if there is anything there...

Robert

[dennis lipsett]

It was made in the 60's along with the 049,both versions, and the Fox 10. An interesting aside is that they also supplied this engine to Comet for their series of plastic ready to fly models after OK Cub went out of business. These engines have the Comet logo on the crankcase.
I have no idea on the plugs. I do know that the Fox 10 head will fit The Fox 09 and the Gilbert 11. Perhaps the 07 fits the Gilbert 07, It wasn't a real powerhouse . I never saw the 07RC used so I can't comment on its performance. My 07 example is from Comet and has their logo on it.Plugs are still available. One source is Virginia hobbies.
Dennis

[Robert McHam]

Dennis, thank you sir for your reply. This is exactly the sort of information I was hoping to get if only in bits and pieces.

This brings up a memory of something I read somewhere regarding the Fox/Comet relationship. I read that for whatever reason Comet sent back, or Fox over produced an engine with the Comet logo and sold these same engines after having ground off the raised logo.

Robert

[dennis lipsett]

Dennis, thank you sir for your reply. This is exactly the sort of information I was hoping to get if only in bits and pieces.

This brings up a memory of something I read somewhere regarding the Fox/Comet relationship. I read that for whatever reason Comet sent back, or Fox over produced an engine with the Comet logo and sold these same engines after having ground off the raised logo.

Robert

Comet ceased production of their RTF planes and went quietly out of that part of the business. Fox from what I understand had to eat the balance of the contract. I got my examples long after their day in the sun as I was past using those sizes of engines by that time.
I'm sure that there are many people that know a lot more then I  and will chime in sooner or later.
dennis

[Bill Mohrbacher]

Fox first made this engine for Comet in 1959.  Around 1961, Fox and Comet got into a battle and Fox took all parts out of Comet.  Having a huge stack of parts, Duke cut the venturi off at an angle, reshaped the little die ejector tab under the bottom of the venturi, cutaway the tank body to leave a rather crude rear cover, ground the Comet cartouche off the case, and Voila, your Fox .07 Compact Stunt Motor.  Peter Chinn reviewed this engine in the July 1961 Model Airplane News.  Doug Martin   Foxengines@aol.com  can supply you with glow plugs and most parts; no pistons and cylinders.  The .07 was sold without a tank.

In 1962 Fox destroked the .07 and made his first .049, it looks just like the .07, but has a little rivet head on top of the piston and 7 instead of 8 cylinder fins (review, P. Chinn, MAN 6/1962).  The .049s were sold with and without a tank.

In 1964 Duke redesigned the .07, made a nice shiny tumbled case, and came out with the .07 RC (P.Chinn, MAN, 5/1964).  This was closely followed by a new .049 with the shiny case (P. Chinn, MAN, 8/1964).

Finally, although advertised in 1963, in 1964 Duke introduced his .049 FAI SPECIAL, an entirely new .049 with a larger diameter crank, different intake and exhaust porting, and a new case.

Also, Fox didn't supply these after OK went out of business.  The Comet RTFs were just too heavy for the Cub .049s.  So Fox supplied an .07.  After the Comet Fox battle, Herkimer (OK) stroked their .049 to make an .060 and that is what went onto the last Comet RTFs.

[Bill Mohrbacher]

I ran out of room on the last post.  Take a look at the tanks.  All of the Comet engines had horizontal cylinder orientation.  All of the Foxes were vertical.  Sometimes you'll see Comet engines on Ebay where the seller has tried to show a vertical configuration and the cylinder is always at a wierd angle.  It must be horizontal!

[Bill Mohrbacher]

Well now you have me started!  I found the first ad for the .07 in the Mar. 1963 MAN.

If you are interested in older model engines, you really need to:
Join the Model Engine Collectors Association (MECA) ( I must plug because now I am president!) http://www.modelenginecollectors.org/

Get a copy of Frank Anderson's "Anderson's Bluebook", pictures and going prices for American engines  http://www.andersonsbluebook.com/

Contact Tim Dannels and get a copy of his "American Model Engine Encyclopedia", fantastic pictues and detailed write-ups and subscribe to Tim's Engine Collectors' Journal  http://www.modelenginecollecting.com/

I've done a lot of writing for all of these outfits, mostly regarding Foxes.  MECA and ECJ will give you lots of contacts, places to get parts, etc.  Ebay is good to find stuff, but the personal exchange is missing.

[kenneth cook]

     Robert,  my father had that engine sitting in a box for nearly 40 yrs. I didn't know it was an .07 but he believed  it was an .049 as well. I asked some questions about it and sure enough one individual posted some pictures showing the casting differences which clearly showed that mine was the .07. I cleaned the engine and had to do some work to a Dave Brown mount but finally got it fit then I mounted it on my Little Tomahawk. The engine sure sounds surprisingly powerful and it flew the plane great but I believe my plug was on its way out. The engine would sometimes die once the igniter was removed. I ended up taking the engine off and switching it out to a Norvel . I took the engine apart one night to clean it up as the castor fuel I was using totally gummed it up to the point it wouldn't turn. I noticed the piston conrod connection was similar to the Cox engines except this had a lot of clearance. I figured I could somewhat reset the joint using the Cox tool which had a horrible result as it cracked the piston in several pieces. I hardly even tapped it. I was lucky enough to score one for a mild price on Ebay which was in nearly new condition. I believe he purchased his engine in 1964. He always told me it ran very well for him. I found it to be quite an easy starter. I wasn't using any high nitro fuel as I thought this engine wouldn't handle it so I just used 10%-29%castor. I very rarely see these engine used. Ken

[Robert McHam]

Ken, thanks for the good news. Someone who actually ran one!
Questions: When you say you were lucky enough to score one for a mild price on Ebay, did you mean just the piston/conrod assembly or a whole engine?

Do you remember what prop you used?

Have you tried to see if any other plug might interchange?

I think it may have performed some better with a little less oil and a little more nitromethane.
In my mind (for which there is room for improvement) all the small engines can benefit from at least 15 percent nitro and as for the oil content, the more castor the better for these older engines however no more than 25 percent total oil content. 22-25%

Now you know where to get some plugs!

Now I want one of these engines to play with myself and a Little Tomahawk to stick it on! Good llitle plane the Tomahawk.

Bill! My goodness! This was the kind of stuff I was hoping for but did not expect to have this much quality info so quickly!
I had no idea of so many variations.

I sure would like to get hold of the two Peter Chinn reports in MAN for the Fox .07.

Bill, I'm not much of an engine connoisseur but from time to time fall for an occasional beauty. Since my interests are for engines .10 size and under, and I am not really a collector, the publications you speak of would be overkill at this time but eventually I will likely purchase these as there were quite a few tiny engines.

Thanks all, and I hope others will offer their experiences and info as well. No need for this to be 'thread over' just yet!

Robert

[Marvin Denny]

  I have a screw and gasket set for that engine and also some backplates.  I have several pistons and shafts and a couple of rods but they may be for the 10 ---I really don't know  they are for anyone with $5.00 plus shipping.  Entire batch sold as a unit.

  Bigiron

[dennis lipsett]

Thanks to Bill for getting the correct info out. I can honestly say that I never saw one of the 049/07 or10 engines while they were in production. That said I did run my examples of the 3 mentioned engines with satisfactory results.
Thanks again Bill.
Dennis

[Bill Mohrbacher]

I need to make a correction.  The 049 wasn't a destroked 07.  It had the same stroke, but a smaller bore.  I never used the .07s, but I flew many, many flights with the 1962 049 on a Jr. Falcon single channel RC and on a Goldberg Lil Jumpin Bean ukie.  I had many, many more flights with the 1964 049 on a Goldberg Jr. Skylane.  I used 6-3 and 6-4 props and usually Fox Missile Mist fuel ("the purple brew thats right for you").

The guys who fly nostalgia FF and Scientific (Musciano) hollow longs hold the .049 FAI in very high regard.  Doug Martin now sells the FAI, made from mostly Fox factory parts.  The .049 glowhead works fine in the .07.

When I get onto my desktop, I'll post the .07 review.  First 2 pages here.

[Bill Mohrbacher]

Here are the last 2 pages.

[kenneth cook]

          Robert, I was able to attain an entire engine which cosmetically looks better than the one I own. I've yet to run it and I surely see no reason why it wouldn't run as it appears to have little use. As for the plugs, I was at a swap meet last year and I picked up two new ones for $5.00. I believe the last time I saw these plugs available was through Virginia Hobby Sports. I was using a Cox grey 6x3 when I made my flights with the Tomahawk. A fellow club member had told me time and time again how the Fox .049's can be some real good runners. I'm guessing the .07 would share the same characteristics. He did say they have a slight flaw in which when running them hard they can blow apart. He has several with broken cranks but he was always happy with them. He drilled out the center portion of the plug and made an adapter out of it which he claimed gave him better rpm's as well. I've always wanted to pick up the tank and mount set just to have the complete engine.

[Robert McHam]

Bill, again thanks! Great reading and I read every word.

This article answered an unasked question regarding the cylinder, whether it was friction fit or threaded. Answer is threaded.

I have to say that I found one possible error. Mr. Chinn states the prop retaining screw to be a 4-40 phillips head!!!
I looked close and indeed it is phillips head (why oh why would anyone do that???) but I gotta say it must be large than a 4-40. I am betting more like a 6-32.

Ken I think I might be right about the fuel and performance. according to the article, Chinn says to use the Fox Missile Mist which is 25 percent nitro in all but the extreme heat, then says to use the Fox Superfuel.

Robert

[Bill Mohrbacher]

Kenneth,  If you want a tank, check with Doug Martin  Foxengines@aol.com

The .049 and .07 used the same tank.  Doug can fix you up.

[Terry Bolin]

This post is just a little behind, I sold a Fox 07RC in Dec. or November. Still looked to be in almost new shape.

[George]

Here is my Fox .07, bought new back in the day. I always wondered why there was a burnish mark on the crankcase. My guess as to why they never became popular is that there were not many planes for them.

Below it are two Fox FAI .049's, bought a few years ago when Randall Hopkins was selling them.

All run well.

George

[Robert McHam]

George, thank you for sharing yours with us!
That burnish mark does look a bit odd doesn't it? At least now you know why it is there.

I will have to disagree on there not being a lot of planes for that size engine. I would say that over 90 percent of the Scientific model kits of that day were labeled and would accept up to .074 engines and the Enterprise and Monarch kits up to .099.
Also any plane that may have been a little anemic on a .049 could have benefited from a mid size like the .07.

The Fox Stunt Runt as advertised sounds really cool. Anyone built one?  I won't say it is an astounding looker but it doesn't look half bad either. And what is the Sky Hook Design?-A real plane saver holds model up on overhead maneuvers.  Some hype! But on the Other hand it wasn't like Duke Fox to overstate his products... Did he?

Robert

[Robert McHam]

Hmm. It just dawned on me that I have asked about the Sky hook design some other time... Unless...

Hmm. Robert

[john e. holliday]

You had to know Duke Fox.  I didn't really know him and had very few conversations with him.  He would pick up my Big Iron with the Fox Combat Special on it and ask what manufacturers dishwater I was running thru it.   In the early years of competition all events were flown by me with K&B 100 fuel.  I would put my Super Tigres under a rag so he wouldn't see it.  I could never really tell much difference between the two engines other than the Fox did not like to restart hot.  That is why I used big tanks. 

[Robert McHam]

Hmm. It just dawned on me that I have asked about the Sky hook design some other time... Unless...

Hmm. Robert

I knew I had this question before! This was regarding another kit with this same feature! Yeppers! The kit was item number F1 the "Sky Hook Trainer" (see pic)
The other thread is here: http://stunthanger.com/smf/index.php?topic=12730.0
and a quote from that thread:

Larry, thanks for that!
Yes that sounds plausible and that thought actually crossed my mind for a very brief moment but I didn't sell myself on it.
Which led me to do some thinking along those same lines. I think more on that later and in another thread where it belongs.

That info about some Berkeley kits having the Fox label is intriguing! I never knew that Fox once owned Berkeley.

Robert

The "Stunt Runt" was kit F2 and was priced at $5.95 while the F1 "Sky Hook Trainer" was priced at $2.29 as of June 15 1961 !!! A quart of Missle Mist fuel was just $1.69! Calgon can you take me back!?! Oh that was "Calgon, take me away" Don't want to be taken away...

Robert

[Robert McHam]

The Goldberg Stunt man 23 was around in 1959 and might have been a fairly decent choice for the Fox 07.

Robert

[dennis lipsett]

The Goldberg Stunt man 23 was around in 1959 and might have been a fairly decent choice for the Fox 07.

Robert

I have one of those hanging around with a fox 09 on it. The tank is through the wing and really the thing is balanced perfectly. For the power that the Fox 09 delivered I'd as soon as used a Cub 074.
Dennis

[philip metzner]

I have a stuntman 23 and a fox .09 and was originally going to put them together. It sounds like i should be glad i didnt.

[Robert McHam]

I'm not sure Duke Fox ever made any real junk in his day but the 'Rocket' 09 was real close. The good news was that it ran. Also good news is that they make good fishing weights.

 Philip, don't mate those two, please! You want happy joyful pairings!

I am playing with one of the Comet versions and it doesn't look exactly like any that have been posted so far. It looks like a cross between the first two pictures shown in Bill Mohrbacher's post number four.

The oddest thing about it I have not read a mention of. There are no bolt holes in the beam mounts!
If you look closely at first picture of te two I just mentioned, it too looks like there are no bolt holes. Not hard to imagine this a being just fine for a designed fit into one the Comet RTFs. They probably didn't use bolts to hold it in place.

More later, Robert

[philip metzner]

I had to drag that engine out and give it another look. I bought it as a fox 09, but i cant find any markings on it at all. It doesnt look like any of the 07 pics here. I has a rear carb coming out of the back of the crankcase where the cylinder screws in, on a upward, rearward angle. It must be a piston valve intake. The crankcase is extended rearward to form part of a fuel tank, or radial mount. There is no rear plate on that radial mount and there is a threaded backplate. I know it will run cause i started it once. Thats all i ever did with it.
 I also have a OK Cub .099.

[50+AirYears]

I had a Fox .09 back about 63-64.  Thought it definitely started easier and had more power than my Cub .099.  I think it was also noticeably heavier.  It did seem to have a possible tank molded into the back, and it was a rear up-angled intake.  No sure what happened to it in the last 40+ years.  Stll have a Fox .049, .074RC, and a Fox .10 RC.  Also my first engine, an OK Cub .099 from about 1949 or 50.

[Bill Mohrbacher]

Some models of the Comet Fox had undrilled mounts.  The engines in the Tripacer RTF and the Regulus where mounted by the tank lugs to the firewall (radial mounts). The beam mounts didn't need drilled on these.  Most, but not all Fox .07s and the first (1962) .049s had undrilled mounts.

Fox .09s had no markings, integral tank, rear venturi.

[Robert McHam]

Thanks for that Bill. It just struck me as odd when I first saw there were no holes drilled.
I think it is something important to pass on to those who don't know.

Robert

[George]

Somewhere in my memory is the thought that some of the Fox .09 parts were also used in the Gilbert .11. Anyone know for sure? I do know that the thrust washer from the baffle Fox .15 fits the Gilbert .11.

George

[Robert McHam]

I have discovered something that others may know but is new to me regarding the Fox 07 engines.

Seems some of the piston-conrod assemblies are like the majority of the Cox 049 pistons in that the rod is a ball-socket affair while some have a plate holding the rod in place using a snap ring to secure it.

Robert

[dennis lipsett]

Somewhere in my memory is the thought that some of the Fox .09 parts were also used in the Gilbert .11. Anyone know for sure? I do know that the thrust washer from the baffle Fox .15 fits the Gilbert .11.

George

The plug from the Fox 09 and 10 both fit the Gilbert 11