Stunt ready Fox .40

Has anyone heard any news of a Stunt ready
Fox 40 being made by Fox.

>Has anyone heard any news of a Stunt ready
>Fox 40 being made by Fox.

There was mention of one at the Fox booth
at the Toledo show. The sleeve is retimed
for stunt.

Hope it is lighter than the standard CL motor

http://www.foxmanufacturing.com/index.php?main_page=product_info&cPath=157&products_id=274&zenid=3641165cfb3f48363a6e87ba35762d3a

Check out the shipping weight

Hey that might be a challenge to balance !

I have a few of the older ones from the mid 1990's they all weigh 9.5 ounces . It looks the same.

Our club has one for sale (we got a bunch of donations from members to sell at swap meets to help our club treasury) If interested, send me an e-mail or message.

>I have a few of the older ones from the mid 1990's they all
>weigh 9.5 ounces . It looks the same.

The Ball bearing engines are lighter than the plain bearing versions (since they don't bore out the case to fit the bearing). There was an older single ball bearing engine with a rear ball bearing and plain bearing front on the shaft. this was the lightest case. The iron piston-cylinder versions are also lighter than the ABC versions, so there are differences.

The lightest--the early single ball bearing with iron piston/sleeve
Medium--present dual ball bearing, iron piston/sleeve
Heavier--present plain bearing iron piston/sleeve
Heaviest--plain bearing ABC (which they don't make, which doesn't mean you can't).

>Hope it is lighter than the standard CL motor
>
>http://www.foxmanufacturing.com/index.php?main_page=product_info&cPath=157&products_id=274&zenid=3641165cfb3f48363a6e87ba35762d3a
>
>Check out the shipping weight


Hmmmm...
It would appear that they pay the same attention to their Ads that they do the quality control of machined parts!


Randy C


As if that's a laughing matter!

Jim,
It appears to be the same C-case motor that they have produced in the past. The intake stack was cut low and they used a new venturi and their new NVA assembly, but the rest looks the same. The P&L are steel. Charlie said something about swinging a 10x6 at 9800 rpm on their test engine. He also said that it should run Lew's engines. Taking some of the weight out would be a good goal so they can compete head to head with the B-40 and DS 40 engines. It would be nice to have a local engine with local support.
FWIW,
John

I always wanted to perfect this engine...being American made & good supply of parts ,etc but I coudn't get it right. I one from SilverFox & it was great , finally wore & lost power.

>Jim,
>It appears to be the same C-case motor that they have produced
>in the past. The intake stack was cut low and they used a new
>venturi and their new NVA assembly, but the rest looks the
>same. The P&L are steel. Charlie said something about
>swinging a 10x6 at 9800 rpm on their test engine. He also
>said that it should run Lew's engines. Taking some of the
>weight out would be a good goal so they can compete head to
>head with the B-40 and DS 40 engines. It would be nice to
>have a local engine with local support.
>FWIW,
>John

If it can only swing a 10 x 6 at 9800 it is a wimp! At least Lew's Fox 40 can swing a 12 x 5 BY&O or similar. That makes up for a bit of the additional weight. It will run rings around the Brodak and Double Starr

I have some square tapered venturis made to fit the Fox RC case and allow you to put the needle where it should be (in the lower hole). I assume these will fit this engine. A medium ST needle fits fine. Get rid of the coarse thread Fox needle.

There's an early 70's Fox 40 Stunt on the Bay right now...

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120399808783

Anyone have any experience with that one?

-Chris

>There's an early 70's Fox 40 Stunt on the Bay right now...
>
>http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120399808783
>
>Anyone have any experience with that one?

It has a nice predictable run, but it's world-class wimpy. It's good for any 35-sized airplane that you would run a 35 in, but it's much larger.

Brett

>There's an early 70's Fox 40 Stunt on the Bay right now...
>
>http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120399808783
>
>Anyone have any experience with that one?
>
>-Chris
>

Bret's right.
Lou Wolgast had one in (I think) a JD Falcon a few years back. It had a descent stunt run but certainly was not in the same ball park with modern 40s in terms of power and was a little on the heavy side.

Randy C

I have 3 of them. I never could get them to not run away.

>I have 3 of them. I never could get them to not run away.

The large case?! That's very surprising, the three I have seen all ran like sewing machines, albeit pretty wimpy sewing machines that spewed a lot of oil.

Brett

>>I have 3 of them. I never could get them to not run away.
>
>
> The large case?! That's very surprising, the three I have
>seen all ran like sewing machines, albeit pretty wimpy sewing
>machines that spewed a lot of oil.
>
> Brett
>

Brett, years ago a acquired one of those Stunt 40's and I thought I really had something.....until I tried to fly stunt with it. It had worse runaway problems than any stock FP. No amount of oil, magic glow plugs, or head shims could solve the problem. Traded it away, post haste.

Clint,

Back in the 1980's I had a pair of the large case 40BB Dykes ring Schneurle CL Foxes that ran quite well, after a bunch of modifying...

I did not fuss with the sleeve timing (should have?), but with the head recut to reduce compression ratio, and (with difficulty) finding the relative tank height that worked for inverted installation, the engine was adequate in power, dead reliable in flight-to-flight unless I fiddled with the needle, and DURABLE. VERY comparable to the OS 40 FSR-S I ran in a second (slightly modified) version of the same design.

Sure, we have more powerful engines these days, about two decades later. Sure, their quirks and positives are better known... For the time, finding a Fox big-frame (read 12 oz vs 9.5) that worked so well was a delight. Required (thinned 12-4 wood, launch RPM ~10,000+, SIG 10/25. Hmmm, wonder what a modern blend would do...), a soft-2 run which is much more common today but a bit unusual then. Only problem, as suggested above, was increased fuel economy. If I tweaked the needle a click or two too lean, I "enjoyed" a 10 to 12 minute flight...

After a few hundred flights, the Dykes ring 'glazed' reducing effectiveness. On a hunch, I pulled the engine, put it on a test stand with a MUCH smaller prop, and ran it a few minutes at 15,000 RPM+. Burnished off the glaze, cleaned out the land. Good for another few hundred flights... Which it provided, at least twice after a scream-session...

Many roads lead to Rome, eh?

>
>Many roads lead to Rome, eh?


Boy, don't they though?

Wimpy, run-away... Sure not what my buddy and myself thought back around 74.. We built these 600 sq/in barn door monster profiles using the 3rd rib out from a Shark 45 and powered them wih large case Fox 40's. We both learned the pattern with the silly things and I sure don't remember worrying about the engine.




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Bob,

Good on ya'

First try on one of my Fox 40BB Sch Dykes was on a Twister, and I didn't have the tank height right. Solid upright and insides; cut dead on outsides, never got to inverted...

As I mentioned to Clint a few posts up, once the tank height and excess compression problems were handled, I had my dog named Lucky. (You know Lucky: incontinent, mangy, flatulent, one-eyed, three-legged and 17 years old...) I was "almost" glad when the model went in, and I could stop looking at that engine for a while...

BTW, was in the Army at the time of that Twister. Knew a bit about "shaped charge" explosives. The face of the explosive is a conical taper, which focuses the force of the blast in a straight column toward the open end...

To reduce the compression ratio, I turned the head button to a straight conical section from stock depth at the cylinder wall, to the end of the plug threads at the center.

Found it interesting that the stock, almost flat squish and small bubble chamber head button had scorch only in the bubble. After a hundred or two hours as a conical shape, the button had a light yellow coloring - no scorch at all! Economy up - sometimes embarassingly - and less vibration...

Found another road to Rome, eh?

I think I have one of these Fox engines inm y basement if someone wants it to use ..I mean fly let me know . ?It needs a strap on muffler real cheap. I think George Aldrich told me he helped engineer this engine I didnt keep all his letters but I do believe it.

John,

I know GMA helped with the 1970's rear exhaust, sand-cast looking 35 or 36, but didn't know if he was in on the 12+ oz banjo-back schneurle. Hmmm...

Hi Lou, long time no write. How are ya? Like I say I can't rememeber for certain but I think George told me he worked on the development of this engine maybe not. I didnt keep all his letters. This engine is not a banjpo back it's a standard looking engine. 8.7 ounces...I bougt it in 1974.

>>>I have 3 of them. I never could get them to not run
>away.
>>
>>
>> The large case?! That's very surprising, the three I
>have
>>seen all ran like sewing machines, albeit pretty wimpy
>sewing
>>machines that spewed a lot of oil.
>>
>> Brett
>>
>
>Brett, years ago a acquired one of those Stunt 40's and I
>thought I really had something.....until I tried to fly stunt
>with it. It had worse runaway problems than any stock FP. No
>amount of oil, magic glow plugs, or head shims could solve the
>problem. Traded it away, post haste.

Is that the one Mike Bush was messing around with? Sounds more like the "giant back door" jobs, than the "large case".

Brett

>
> Is that the one Mike Bush was messing around with? Sounds
>more like the "giant back door" jobs, than the
>"large case".
>
> Brett


No, I don't think Mike ever fooled around with these. It was the large case 40 and not the tall back door model. The one that says "stunt 40" right on the box. In fact I had two of them, one was NIB that I never even tried after having so much trouble with the first one.
Sometimes I just don't have any luck with something that someone else has great success with, and vice versa.