FOX .15 STUNT ENGINE
#1
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Howdy all......I recently fired up an old bypass port .15, the one that looks like a baby brother to the Stunt .35.
I bought it 2nd hand 20 years ago.
What years were these made?
This engine has always served me well, runs great with a muffler... it pulls a British Diesel Warlord better than any PAW .15 could hope to do.
I bought it 2nd hand 20 years ago.
What years were these made?
This engine has always served me well, runs great with a muffler... it pulls a British Diesel Warlord better than any PAW .15 could hope to do.
#2
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Ye gads man, I'm not sure when they were actually being made but I've got several still in use from theearly 1970's and they still run GREAT!!! I'm not sure that they can actually ever be "broken" - they just seem to go on forever and ever.
Enjoy yours!
Dave</p>
#3
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Thanks, Dave! That gives me some idea of how old it is. I stumbled on [IIRC] Preston Brigg's website about C/L combat and there was a complete listing of every FOX Combat Special ever made since 1957. He included some side notes about other engines, too......but didn't mention the .15. Somewhere, someone has a complete list of every engine they ever made including all the revisions?
The engine I have has been in the same state of "wornoutness" since I got it, but it still empties out a 2 oz tank every flight.
The engine I have has been in the same state of "wornoutness" since I got it, but it still empties out a 2 oz tank every flight.
#4
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<div id="msg_113480" class="post">Peter Chinn "Latest Engine News",Model Aircraft (British) June 1962. discusses the Fox 15X and 15XX. These are later models which look sort of like a Stunt 35. The 15X on 20% nitro turned Tornado 8 x 4 at 11,600 RPM, The 15XX turned 12,800. I don't know about modern 15 glows, but Ron Warring, "Engine Analysis", Aeromodeller Jan. 1962 gives figures for the short-lived TD 15 of between 15,200 - 16,000 on 20% nitro. A TD 09, way overpropped, on 30% nitro, will turn an 8 x 4 at 13,200. A Medallion 09 is about the same as the two models Fox 15 with an 8 x 4.</div>
I had posted this on anoher forum.
![](http://stunthanger.com/smf/Themes/dilbermc/images/icons/modify_inline.gif)
I had posted this on anoher forum.
#5
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Jim, thanks for the info! This one doesn't have an X stamped on it, but it looks very similar to the .35 Stunt. I haven't tached this one, it's too worn out to fool around with different props, it likes the "white trash" Tornado 7x6 and that's about it.
This would make a doable engine project someday [for someone like me with more patience than skill], to cut out a new piston for a re-honed liner.
This would make a doable engine project someday [for someone like me with more patience than skill], to cut out a new piston for a re-honed liner.
#6
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The first Fox 15 baffle I had was a "learning experience..." That was the first run of them in the mid/late 1950's, which had a finned, steel sleeve. Some, so I'd heard, ran well. Not enough, apparently as Fox changed to the die-cast , full-height crankcase with drop-in steel sleeve around early 1960s? Better, but not always, or for everyone. I've had a few that did quite well, if you allow for what they actually can do. Still considering one for a friend's current project...
Surprised to hear it tows a Warlord better than a PAW15! ...ANY PAW .15??? Hmmm...
I seem to recall that my better ones like 10%-15% nitro, and 25% castor, on a light, clean 8-4 wood prop. Flight setting in steady-2-cycle, backed off just a bit from peak.
The X and XX models were different from the main production version. I regret that the 2.5cc/.15 cu in size didn't catch on here as a sport engine size. Goodyear Racing and (in the USA) relatively few FAI Combat fliers wanted lotsa lotsa power.
Surprised to hear it tows a Warlord better than a PAW15! ...ANY PAW .15??? Hmmm...
I seem to recall that my better ones like 10%-15% nitro, and 25% castor, on a light, clean 8-4 wood prop. Flight setting in steady-2-cycle, backed off just a bit from peak.
The X and XX models were different from the main production version. I regret that the 2.5cc/.15 cu in size didn't catch on here as a sport engine size. Goodyear Racing and (in the USA) relatively few FAI Combat fliers wanted lotsa lotsa power.
#7
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Hi Lou, thanks for some more history! Mid 50's, I was just an embryo....![Big Grin](https://www.rcuniverse.com/forum/images/smilies/biggrin.gif)
My PAW .15s are pretty representative of the gene pool....up until a few years ago I flew Diesel Bat with about a dozen other regulars during breaks in the glow combat schedule. Lots of fun and low maintenance. We allowed only nylon 8x6s and the planes were clocked for 65 mph [about 2 mph above stall speed].
Your recollections of .15 glow flight with a 8x4 have got me thinking about building a little stunter......thanks a lot, now I've got to finish 4 other projects and hose out the workshop!
![Big Grin](https://www.rcuniverse.com/forum/images/smilies/biggrin.gif)
My PAW .15s are pretty representative of the gene pool....up until a few years ago I flew Diesel Bat with about a dozen other regulars during breaks in the glow combat schedule. Lots of fun and low maintenance. We allowed only nylon 8x6s and the planes were clocked for 65 mph [about 2 mph above stall speed].
Your recollections of .15 glow flight with a 8x4 have got me thinking about building a little stunter......thanks a lot, now I've got to finish 4 other projects and hose out the workshop!
#8
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CP, good choice!
Ringmaster Jr., Flite Streak Jr. Both a good choice or you can have what is behind curtain three:
http://www.sigmfg.com/cgi-bin/dpsmar...trol_20Line_01
Robert
Ringmaster Jr., Flite Streak Jr. Both a good choice or you can have what is behind curtain three:
http://www.sigmfg.com/cgi-bin/dpsmar...trol_20Line_01
Robert
#10
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Actually they are very decent to deal with and the have some great deals on thier 1/2A kits too!
http://www.sigmfg.com/cgi-bin/dpsmar...FV4.html?E+Sig
Dollar for dollar I don't think you can beat the price of the Staggerwing Beechcraft. The decals have metalflake in them! Really cool!
Robert
http://www.sigmfg.com/cgi-bin/dpsmar...FV4.html?E+Sig
Dollar for dollar I don't think you can beat the price of the Staggerwing Beechcraft. The decals have metalflake in them! Really cool!
Robert
#11
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The "Steelfin" Fox .15 came out in 1958. The next generation was the .15X which has a drop-in liner. This was released in 1960 if I remember correctly. I think the XX was like the X except it had a better bronze for the shaftbearing. There was also a special XXX.
The X went through several iterations. The one in the lower left is the first X, note that it has no muffler provisions. The others shown mount the muffler with over/under screws. I also have one on an Akromaster that has muffler ears on the sides of the stack.
Note that the steelfins have no provisions for muffler. The one with the "square" fins is the first version.
George
The X went through several iterations. The one in the lower left is the first X, note that it has no muffler provisions. The others shown mount the muffler with over/under screws. I also have one on an Akromaster that has muffler ears on the sides of the stack.
Note that the steelfins have no provisions for muffler. The one with the "square" fins is the first version.
George
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The "Steelfin" Fox .15 came out in 1958. The next generation was the .15X which has a drop-in liner. This was released in 1960 if I remember correctly. I think the XX was like the X except it had a better bronze for the shaftbearing. There was also a special XXX.
The X went through several iterations. The one in the lower left is the first X, note that it has no muffler provisions. The others shown mount the muffler with over/under screws. I also have one on an Akromaster that has muffler ears on the sides of the stack.
Note that the steelfins have no provisions for muffler. The one with the "square" fins is the first version.
George
The X went through several iterations. The one in the lower left is the first X, note that it has no muffler provisions. The others shown mount the muffler with over/under screws. I also have one on an Akromaster that has muffler ears on the sides of the stack.
Note that the steelfins have no provisions for muffler. The one with the "square" fins is the first version.
George
- I realize this is an older conversation article on a Fox.15, but I still have questions not answered in the blog. What fuel ratio do these use, is it the same as a Fox35? Where does one obtain gaskets? Is a gasket between the cylinder and crankcase necessary? I hope someone still reads these.
- Al
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For more information on the Fox .15 (parts and manuals), see the following link: FOX 15x R/C & U/C
They do not appear to state what % oil to use in those manuals, but they do mention what fuel it runs best on. Knowing that, you can get more info on the fuels here: Fox and K&B Fuels
They do not appear to state what % oil to use in those manuals, but they do mention what fuel it runs best on. Knowing that, you can get more info on the fuels here: Fox and K&B Fuels