A "hurlable" Fox .15?

Why would one hurl that? A little cleaning and it would look like a nice little engine.

It makes me want to hurl just looking at it.

The one you show is the Rocket .15 steelfin. The Fox .15 that's hurled would be the .15X. However, I would say those whom participate would certainly not be objected to hurling it. I'm a big fan of Fox .15's and I never had an issue with getting them run. I truly enjoy them and they're great little engines. The steelfins need to be treated with a little extra caution. The wrist pin ends tend to cut grooves in the liner. I would also say that the backplate is on backwards.

lol, my first 'big bore' engine, something larger than a .049 was a Fox .15X, purchase it with paper route money in 6th grade, bolted it to a Ringmaster Jr.

The seller didn't offer a good picture of the back plate, about the best one. But it should fit inside the case. Hope the gasket is intact.



At least it's got the needle valve.  I think that it will clean up nicely and I will check that wrist pin exposure Ken.  Looks different from other Rockets that I have seen which have a much smoother case profile.  I passed on one last week that I should have grabbed.  The "steelfin" must be somewhat different.  Must like 5/10% nitro?  

Bob

Looks like there is gasket there on the exterior of the backwards backplate. Probably/maybe the PO installed it that way, because if installed properly it would rub on the crank and connecting rod.

Mark Boesen wrote:lol, my first 'big bore' engine, something larger than a .049 was a Fox .15X, purchase it with paper route money in 6th grade, bolted it to a Ringmaster Jr.

I call anything larger than a .049 a "Big Boy" engine Mark.  

But this is the one I'm most proud of, now on it's way to WV from sunny California.





Chances are you will never see another one.  Found one in better almost new condition a few months back and showed it off to all my Enya friends.  Even Bob Allan knew nothing about it (Wrote the 80 some page Enya "compendium") and earned me an honorable mention in his latest edition.  Bobby Brooks, the Enya parts guy knew nothing of it's existence either.

So, your curious..maybe, maybe not.  The .09II succeeded the first ever Enya .09 the model 3001.  Whole different engine with a completely different case.  The 3001 had Made In Japan cast on the left bearer the ,09II did not.  For some reason these slipped through before the mold was changed.  There may be others, but maybe not.

First Enya .09 3001 (developed late 50's) with a normal (1960's) Enya .09II.  The II was quickly succeeded by the 09III and IV.







Maybe Rod my fellow Enya lover has seen one that slipped it's way into Australia?

Bob

Bob, your example is certainly in need of some care. In one of your posts recently you expressed a Babe Bee which you also had some additional parts. I commented on the gasket as it was for a Fox Stunt .35. You also pictured a needle valve which was needle only. That needle is the needle for this .15. Certain parts do interchange from the rocket to the X series such as drive plate, crank. I believe the backplate gasket as well so if yours is damaged, these should be relatively easy to find. These engines do like nitro. I run them on 10%-15%. The oil content needs to be high, 25%-29% oil. It's typical Fox with slop everywhere and that heavy oil just takes up the tolerances. I keep the prop sizes in the 7x4-7x6 range. The .15X turns up higher than the steelfin but the steelfin makes for a great sport .15.

I have two Fox .15 steel-fins, although they are not Rockets. I think that Ken might have mentioned the wrist-pin problem a while back when I posted about mine. If he mentioned a fix for that problem.. I didn't save it to a text-file as I often do with his recommendations. If there "is" a fix.. I'd certainly want to try to apply it.

This one would be my "runner".. It was my Grandfather's.




My other one was stuck/siezed.. and had its' backplate center-drilled for a crank-pressure tap. It was my Uncles'



I tapped the backplate and installed a screw to seal it off.



The latter (seized one) became the victim of a then inexperienced-Roddie. In an effort to "un-stick" it.. I pulled the head, set the case in a fixture (vise.....) and proceeded to tap the top of the piston with a hardwood dowel and hammer.. resulting in denting-in the top of the piston.. as well as freeing it up. Knowing what I know now; I probably could have freed-it with some heat.

On a more positive note; I do have the runner and a parts-engine (less piston)

When my Grandfather gave me his; he included an expansion-chamber. It's an obscure item.. in that there are no markings.. other than my Grandfather's etched name. It's just a bit too sophisticated to be home-made.. and I never thought to ask him where he got it. It fits snugly over the exhaust-port.. and probably is held by a tension-spring around the back of the cylinder.






I've never run it... with or without the muffler. I need to source proper fuel for one thing. Gramps' engine is pretty clean.. and may not have ever been run. When I run it.. I'll treat it to a few break-in cycles; open-face.. and see how it runs.

Here are images of the original operating manual.









I hope that you can get your engine running Bob! I have a Jr. Ringmaster waiting..  with its engine-bearers drilled for mine!

My understanding of the "fox 15 hurl" is for the ball bearing schnurle ported engine that was written out of the rules for some particular event. (combat I think)

That is NOT a hurling engine.

Phil

pkrankow wrote:My understanding of the "fox 15 hurl" is for the ball bearing schnurle ported engine that was written out of the rules for some particular event.  (combat I think)

That is NOT a hurling engine.

Phil

Amen.. and if you're an American.... you naturally have a love for anything well-designed and built here.

I have never known the BB .15 to be the engine to hurl. The Fox .15 BB is a very good engine. Aside from their weight, they offer a lot of power. The slant plug .15X is the hurled Fox. The running joke is that this is the only way to get it airborne.

Roddie, the steelfins use a fiber base gasket. I would only take these apart if absolutely necessary. If you take the head off and start to see signs of the wrist pin marking wear paths in the sides of the cylinder, I would take it apart. Grinding the end of the wrist pin and applying a radius around the perimeter followed by a good polishing is how you buy some more time. I use drill rod if the wrist pin is too loose, I then drill into the end of it and make Delrin end pads. This type of construction was typical with K&B and a few other manufacturers.

Folks have been recommending the Fox .15X for planes of class 200 square inch wing area. Comparing Sceptre Flight Engine Tests, it and my Enya .09-III are in the same ball park HP wise.
Regarding Bob's engine, I'd say go for it, give a good clean up and match it up with a suitable airframe.

Ken Cook wrote:
Roddie, the steelfins use a fiber base gasket. I would only take these apart if absolutely necessary. If you take the head off and start to see signs of the wrist pin marking wear paths in the sides of the cylinder, I would take it apart. Grinding the end of the wrist pin and applying a  radius around the perimeter followed by a good polishing is how you buy some more time. I use drill rod if the wrist pin is too loose, I then drill into the end of it and make Delrin end pads. This type of construction was typical with K&B and a few other manufacturers.

Thanks Ken. A save of this advice revealed a previous saved document of your's from an older thread or PM that I overlooked. I'll summarize between the two, before running my engines. Thanks "again"!

Ken Cook wrote:I have never known the BB .15 to be the engine to hurl. The Fox .15 BB is a very good engine. Aside from their weight, they offer a lot of power. The slant plug .15X is the hurled Fox. The running joke is that this is the only way to get it airborne.

Ah. OK. That makes sense.

I have a Fox 15 BB with extra parts I likely will never use. I felt it was "strong" when bench running, but I had a bad carb and it was a nightmare so I never flew it. Fox took care of me before closing their engine service.

Phil

Wow, talk about casting your bread upon the waters..........thanks guys for all the responses, help, and education.

Wonderful pictorial roddie. Too bad about your learner. But I did the same thankfully with .049 Wens and McCoys using a hammer and dowel to "free" the piston.

Early on I tried heating them in a pot of boiling Simple Green, did no good until someone here, Rod maybe turned me on to crock pot cooking with anti freeze and/or a heat gun.

Now I just pass a heat gun over seized engines then boil if necessary. Easy pesey in the extreme.

Bob

On the Fox .15 Steel-fin you might find that when adjusting the needle the needle will move slightly after you let go. It is caused by the spring. I found that adding a washer or filing the end of the spring will correct this.

The Fox .15X (slant plug) hurl was created buy some guys in CA. Someone couldn't get his .15X started so others offered to help. The owner got so frustrated he pulled the engine and hurled it. Other guys laughed, then thought about it and the Fox hurl was born. I believe that only the Fox .15X is eligible. Perhaps one of the California guys will add more info.

The Fox .15 steel-fin does not like to be over propped. An 8x4 or a 7x6 should be max.

George

I particularly like Roddie's stamped steel muffler. that must be something from the 1940's or 50's. It was amazing what they could do with stamp steel machines then. I remember seeing a WW2 "grease gun" in an arms room at a National Guard armory in the 1990's. It had a .45 caliber pistol round clip, except for barrel was all made of very heavy gauge stamped steel. I heard that tank crews carried them, because it could be easily carried entering and exiting a tank. IMO, Roddie's muffler is a rare one, indeed.

A careful and thorough reading of the instructions was fun and caused a few eyebrow raised areas...example: cleaning off the crashed engine with Carbon Tet

On Stunt Hangar the various threads about the Fox Hurl are funny and I usually wonder if the event ever really happens or is just a bunch of old guys hanging out and pontificating with mucho alcohol... the rules are semi secret... (really non existent IMO) and the characters discussing the differing ways to Hurl, GPS location, effects of gravity, and other non sense can be quite entertaining(funny)

I really enjoy the topic and banter

Yes, Carbon tetrachloride, bad stuff. Toxic.

In the two years I ran in the Soap Box Derby the stewards would give us squirt cans of the stuff to clean the sand out of our wheel bearings after each run. At the bottom of the track was a long sand pit there to stop the racers.

I never get over (seldom) to SH but I do visit RC Groups occasionally.

Bob

The steelfin 15 and the 15xs had press fit wristpins.  The pin was free in the front hole (towards the venturi) and press in the rear hole.  The pin is pressed forward to remove and slipped in the front and pressed home to install.  Of course with Fox tolerances, you might expect it to slide forward.


The Steel fin and the .09 were never marked as Rockets.  When the Rocket 35 came out (that was marked as a Rocket) Fox had an ad saying that that his new low priced line would hereafter be known as Rockets and included his 35, 15, and .09.  There was no difference between a steelfin and a Rocket.

Also, Fox used the Rocket crankcase casting (2 version with lugs on front) for his Series 3 needle bearing Combat Special.  He cut the front crank journal off and machined the case to accept the needle bearing front end.  Thus the needle bearing engine with the removable front end is often called a Rocket, but it is a COMBAT SPECIAL.

Ken, nice to meet you and your son at GSCB swap meet Ken.  See you at Lebanon.

Oldenginerod wrote:... but I really fail to understand why they are held in such high esteem.

I grew up flying Cox and Fox engines. I doubt I am the only one.

My Dad favored McCoy in 19 and 29. Mom flew the same engine choices.

We always wanted OS and Enya but Dad as a mechanic and Mom teaching school there wasn't budget for pricier engines. We stopped flying as a family when my older brothers were in high school.

Phil