Author Topic: Fox 35 Stunt Evolution (Read 6946 times)

Motorman · « **on:** March 29, 2016, 10:59:26 PM »

From what I can tell, Fox kept the original 35 stunt design in production but also developed an offshoot with improvements to the design that eventually culminated with the Fox 36X BB. If you look on the upper cylinder of the 36x you'll see remnants of the 35 stunt design.

What I'm interested in is all the 35 size engine designs that came right after the Fox 35 stunt that looked some what like the 35 stunt, like the two foxes BadBill has in the classifieds right now. I'd like to map the time line of improvements.

When did he change the venturi, when did he go to a 4 bolt back plate, did they all use the same crankshaft before the needle bearing version ect. Is there anyone who has a collection or just knows the specs of all the variations?

Thanks,
MM

BOB ALLAN · « **Reply #1 on:** March 30, 2016, 02:19:50 AM »

The best thing you could do, is get a copy of the American Model Engine Encyclopedia Volume 2

Frank Imbriaco · « **Reply #2 on:** March 30, 2016, 05:02:59 AM »

The four bolt / different venturi Fox 35 pictured in the classifieds is what appears to be the first Fox combat engine. Plain bearing.That came out in 57, followed by similar Blackheads(58) and then , the Rocket. Same mount bolt pattern as Stunt 35; nothing else.
In 1972-73, a Duke came out with a plain bearing engine for slow combat that at a quick glance, looked like a stunt 35. Totally different. 4 bolt backplate , angled plug, and internally snotted up( read no 2-4), different venturi with an insert. It was a 36 and the 29 looked the same, sans "29" on the crankcase. Both good runners.

Paul Smith · « **Reply #3 on:** March 30, 2016, 06:07:31 AM »

When I got into the game, around 1960, the needle bearing Fox Combat was his premier engine. Other than the name, it had nothing in common with the Fox 35 Stunt.

Fox produced .35 cubic inch combat engines for a long time before he got wing that people favored the JBB 36 because the additional displacement. At that point Fox began producing stroker cranks to go from .35 to .36 and combat flyers gobbled them up.

Rat Racing allowed .40, but nobody offered 40's so everybody settled for 29's 35's and 36's. Fox was quick to come out with a .40, and gold-plated too.

Robert Zambelli · « **Reply #4 on:** March 30, 2016, 06:17:31 AM »

MM: Maybe this will help (not sure if it's been posted before)
Bob Z.

Motorman · « **Reply #5 on:** March 30, 2016, 10:53:06 AM »

Those pics are nice, thank you but, not what I was looking for if you read the OP.

MM

ChrisSarnowski · « **Reply #6 on:** March 30, 2016, 02:50:28 PM »

I don't know if you have seen them MM, but there are a bunch of Fox engine reviews on this web site: http://sceptreflight.net/Model%20Engine%20Tests/Index.html

You can look at the 29's and 35's to get a start on that timeline.

-Chris

Clint Ormosen · « **Reply #7 on:** March 30, 2016, 08:41:20 PM »

Quote from: Chris Sarnowski on March 30, 2016, 02:50:28 PM

I don't know if you have seen them MM, but there are a bunch of Fox engine reviews on this web site: http://sceptreflight.net/Model%20Engine%20Tests/Index.html

You can look at the 29's and 35's to get a start on that timeline.

-Chris

Whoa!!! It's Chris S. How ya doing buddy?

Dan McEntee · « **Reply #8 on:** March 31, 2016, 07:23:28 PM »

Quote from: Motorman on March 30, 2016, 10:53:06 AM

Those pics are nice, thank you but, not what I was looking for if you read the OP.

MM

The Fox .35 Stunt remained virtually unchanged internally throughout it's entire production run. It changed cosmetically with the addition of muffler ears and some extra metal around the venturi and the changing "Anniversary" ribbon on the left side of the engine. It went from the sand cast four bolt head/two bolt back plate to the die cast six bolt head and three bolt back plate and then the minor surface changes over the years. There were no off shoots of the Fox .35 Stunt. Fox and George Aldrich collaborated on a .40 that wasn't much of a success, and was vastly different than the .35 Stunt. If you have a Fox engine that has more that three bolts in the back plate, it ain't a .35 Stunt.
Type at you later,
Dan McEntee

frank mccune · « **Reply #9 on:** April 01, 2016, 11:26:24 AM »

Hi Dan:

Can you tell me why the Fox .40 Stunt that you mentioned in your above post was not a success?

Tia,

Frank McCune

RandySmith · « **Reply #10 on:** April 01, 2016, 12:29:21 PM »

Quote from: frank mccune on April 01, 2016, 11:26:24 AM

Hi Dan:

Can you tell me why the Fox .40 Stunt that you mentioned in your above post was not a success?

Tia,

Frank McCune

The engine your asking about was a success so far as it ran very well and as intended, I have 2 here and the run very well as stunt engines, the fact it was not a Commercial success maybe because of the new Loop charged engines coming online at that time, and the old ST 46 ..about the same weight but much more power, and the HP 40, lighter with more power

Randy

frank mccune · « **Reply #11 on:** April 01, 2016, 02:48:25 PM »

Hi Randy:

Thanks or the reply.

I have been using one of these old Fox .40 Stunts for quit awhile and I am very pleased as to the performance that they provide. A very steady 4-2-4 break and one flip starts. Yes, they are heavy, but so was the ST .46 and the slightly heavier HP .40 I do not think that it fair to compare a Fox engine to a ST or a HP. The Fox was a very inexpensive, $14.95, engine as compared to the other engines that not only cost much more but were made with ball bearings, ported pistons, better materials and better fits. It is like comparing a Ford to a Ferrari. Both will get you there, but...

Be well my friend,

Frank McCune

RandySmith · « **Reply #12 on:** April 01, 2016, 02:59:33 PM »

Quote from: frank mccune on April 01, 2016, 02:48:25 PM

Hi Randy:

   Thanks or the reply.

   I have been using one of these old Fox .40 Stunts for quit awhile and I am very pleased as to the performance that they provide. A very steady 4-2-4 break and one flip starts. Yes, they are heavy, but so was the ST .46 and the slightly heavier HP .40 I do not think that it fair to compare a Fox engine to a ST or a HP. The Fox was a very inexpensive, $14.95, engine as compared to the other engines that not only cost much more but were made with ball bearings, ported pistons, better materials and better fits. It is like comparing a Ford to a Ferrari. Both will get you there, but...

   Be well my friend,

   Frank McCune

Hi Frank
I do not think you understood what I wrote, consider this, most people who wanted the best power plant for that era, did NOT buy the FOX 40, it was heavy, not as well made, and lacked the power of the lighter HP 40, It was also not as well made as the Loop charged FSR type engines, which were better made and more power, this was what I said in the above post. I understand cheap.. but Stunt flyers , by the large part, did NOT buy their power plants on price alone.
When it came to a 20 dollar FOX or a 30 dollar ST or OS it really was not much of a choice for most people.
Then throw in the older, OS 40H and OS 50, OS 35S and there was just TOO much competition!

Regards
Randy

Motorman · « **Reply #13 on:** April 01, 2016, 06:35:41 PM »

Did Fox make a plain bearing 35 engine with a shaft bigger than 7/16ths?

MM

BOB ALLAN · « **Reply #14 on:** April 02, 2016, 12:49:13 AM »

Quote from: Motorman on April 01, 2016, 06:35:41 PM

Did Fox make a plain bearing 35 engine with a shaft bigger than 7/16ths? MM

Late 1950's, early 1960's FOX Rocket 35 and Combat Special

Curt D Contrata · « **Reply #15 on:** April 02, 2016, 06:20:58 AM »

Fox 40 stunt...

Was that the one with the really long mounting lugs from the 70's?

Curt

frank mccune · « **Reply #16 on:** April 02, 2016, 08:10:23 AM »

Hi Curt:

Yes, that is the engine that I was referring to in my post.

I picked up some of these engines for a few bucks over the years and have had one in a Magician for many decades. Yes, they are heavy but as a stunt engine, they have proved to be very good. One must remember that they are NOT the best engines in the world but quite adequate for their purpose. I have to check to see if they put out more hp that my O.S. .40 Stunt from the same period. I am awaiting a good tach before I make any tests.

No matter what engine one chooses, there are often an engine out there that is better. Remember the day when you had a fast car, there was always a faster one somewhere. Lol

Orlando: I spent the month of Feb. in that area. I prefer the traffic in NYC! Lol

Be well,

Frank McCune

Curt D Contrata · « **Reply #17 on:** April 02, 2016, 08:26:03 AM »

Quote from: frank mccune on April 02, 2016, 08:10:23 AM

Orlando: I spent the month of Feb. in that area. I prefer the traffic in NYC! Lol

Be well,

Frank McCune

Orlando, the city of u-turns and tourist drivers! Stay off I-4 and it is not so bad.

I had a buddy back when I was a kid, we were still flying Junior, he had one in a Midwest King Cobra. I think he won the KOI with it (in junior). My dad and I had one, the R/C version, in a Sterling Skyshark. Horrible combination! Was not till later when we found out it was not 300 square inches. It eventually was used for endurance since it could support a 16 ounce tank.

Curt

Bill Mohrbacher · « **Reply #18 on:** April 03, 2016, 05:13:59 PM »

Quote from: Motorman on April 01, 2016, 06:35:41 PM

Did Fox make a plain bearing 35 engine with a shaft bigger than 7/16ths?

MM

Yes - all covered in detail in ECJ. The 36X was NOT and offshoot of the Stunt 35. The stunt 35 was one die and the 36Xs another.

Motorman · « **Reply #19 on:** April 03, 2016, 09:27:48 PM »

Ok I'll bite, what is ECJ engine collectors journal?

MM

Bill Mohrbacher · « **Reply #20 on:** April 04, 2016, 10:11:34 AM »

It is Engine Collectors Journal. The pic Bob Z posted were all mine as used on ECJ and posted long ago on SSW and RC Groups and probably here.

Author Topic: Fox 35 Stunt Evolution (Read 6946 times)

ChrisSarnowski