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General control line discussion => Open Forum => Topic started by: Phillip Kenney on September 13, 2012, 03:41:31 PM

Title: Fox 35 Mufler
Post by: Phillip Kenney on September 13, 2012, 03:41:31 PM
I have a Fox 35 Stunt, circa 1978 that didnt come with a muffler that I would like to find a muffler for. The mounting lugs above and below the exhust  are tapped, apparently 2-56 thread. Any suggustins on a source for one?  I have not seen any with mounting above and below the exhaust.
Title: Re: Fox 35 Mufler
Post by: bill bischoff on September 13, 2012, 05:03:44 PM
Only Fox ever made a muffler to mount that way. It seems that they had rather a reputation for coming loose. Perhaps that's why the changed to the more standard muffler mounting pretty quickly. You'd need to find one of the old Fox mufflers if you really wanted to use original muffler mounting scheme.
It may be easier to mount your engine parts into a new crankcase so you can use a wider variety of mufflers.
Title: Re: Fox 35 Mufler
Post by: Bob Matiska on September 13, 2012, 05:06:54 PM
Phil,

Fox made at least two mufflers for the Stunt 35 back in the 1970s that I know of, one with an open front and one closed. I have one of the open types and I will tell you: It is a lousy muffler! The only time I achieved any noticeable sound reduction was when I pulled out the center tube and wrapped it with steel wool and put it back in. I have no experience with the closed front unit but it must be better at silencing this fine engine. You'll note that the mounting lugs on the muffler are pretty weak and in fact the bottom lug on mine is broken, though a screw with a washer will still hold it in place. Note that I would feed some .030 steel wire through the muffler and wrap it around the case and twist it snug, just to make sure the thing would stay in place. Also note,  by the way, that most flyers who would stuff a muffler with something would recommend copper wool, just in case a strand of the metal made its way into the cylinder. Copper would be more likely to shear and not ruin the piston and cylinder than steel wool.

I have a very nice Aero Products tongue muffler for the 50th anniversary Fox and just noted that with the screws just barely in the muffler, it will slip down over the cylinder and onto the exhaust port. So making a metal strap with some ears on it and drilling two holes in same ears would probably mount it on the older Fox. I would also probably cut the heads off a couple of 3-48 screws (they're not 2-56s, I'm sure) and thread them in with my fingers, just to make sure the tongue muffler didn't slide up and down.

Looks like it's time to learn how to take and size and upload pictures here to show what I'm talkin' about....


Bob
Title: Re: Fox 35 Mufler
Post by: Wayne J. Buran on September 13, 2012, 06:35:06 PM
I have in my hands a Fox muffler for that engine with the over under screw. It is the closed front version.  BTW it also has mounting screw holes on the ends so you can make a strap for it. You should also know that the muffler in question wraps itself around the exhaust stack which should be a rectangle. It's used and available.
Thanks
Wayne
Title: Re: Fox 35 Mufler
Post by: Steve Hines on September 13, 2012, 06:38:33 PM
Randy Smith has the mufflers that you need. He had me fill in the top and bottom holes with JB weld, they will leak out oil out of them. You could put in screws in and grind them off. I was told this weakend that the LA mufflers and evolution 36 would work I have not tryed one to see if it works.

Steve
Title: Re: Fox 35 Mufler
Post by: Steve Helmick on September 13, 2012, 07:10:29 PM
Magnum XL .25 > .36 and XLS .32/.36 mufflers also fit. Some of them are the same, but .36 mufflers generally have a center tube added to increase the volume at the expense of a bit of weight. They're smaller and lighter than OS .40/.46LA mufflers, at least.  y1 Steve
Title: Re: Fox 35 Mufler
Post by: YakNine on September 13, 2012, 07:55:51 PM
I have an Evo .36 tube muffler with a Jan Holuszco clamp to hold it on without distorting the case. The only thing I don't like about the muffler is its close to the prop when hand propping. T.J.
Title: Re: Fox 35 Mufler
Post by: Jim Kraft on September 13, 2012, 08:11:37 PM
Andrew Hathaway and I have been running our Fox 35's without mufflers. After flying Fox 59's and Anderson Spitfires, they seem rather quiet. They also run better and make a little more power. Open exhaust McCoy Red Head's are just a little quieter I think. "What's that you say"?
Title: Re: Fox 35 Mufler
Post by: YakNine on September 14, 2012, 04:55:54 PM
Brodak is showing a muffler strap for putting a muffler on a Fox 35 1st picture in muffler section
Title: Re: Fox 35 Mufler
Post by: Brett Buck on September 14, 2012, 05:19:33 PM
I have a Fox 35 Stunt, circa 1978 that didnt come with a muffler that I would like to find a muffler for. The mounting lugs above and below the exhust  are tapped, apparently 2-56 thread. Any suggustins on a source for one?  I have not seen any with mounting above and below the exhaust.

   I am pretty sure you don't want to use that muffler mounting, even if you can find a muffler for it. It's extremely prone to breaking off in the slightest crash, AND, it carries a high likelihood of distorting the case and cylinder. For the cases with the over/under holes, but not the fore/aft holes, use a strapon muffler. For those cases with the short fore/aft mounts, JB weld some appropriate brass tubing from against the existing lugs to the exhaust flange, and use that for a muffler mount. The fore/aft mounts will also break off very easily. This modification makes the mounts look like the 50th Anniversary model which in turn is a dead ringer for the last version ST46.

   When I last ran Foxes seriously I was still using open exhaust - which tells you how long ago that was.

   Brett
Title: Re: Fox 35 Mufler
Post by: john e. holliday on September 15, 2012, 08:45:11 AM
I am keeping secret what will go n my Yak 9 kit.   Have to finish the P-47 before Pat comes and reclaims it.
Title: Re: Fox 35 Mufler
Post by: YakNine on September 15, 2012, 05:18:46 PM
here is my 35 with the Evo .36 muffler and holuszco clamp. T.J. PS it doesnt touch the case on the bypass side only on the edge of the exhaust port.
Title: Re: Fox 35 Mufler
Post by: YakNine on September 15, 2012, 05:20:04 PM
one more pic.
Title: Re: Fox 35 Mufler
Post by: Bill Little on September 15, 2012, 08:02:12 PM
I have an Evo .36 tube muffler with a Jan Holuszco clamp to hold it on without distorting the case. The only thing I don't like about the muffler is its close to the prop when hand propping. T.J.

Ok, I got a question! ;D  Where does one get the "Jan Holuszco" muffler clamp?  I could definitely use one or two!

Thanks!
BIG Bear
RNMM/AMM
Title: Re: Fox 35 Mufler
Post by: Avaiojet on September 16, 2012, 10:54:52 AM
Not sure if this is what your referring to?

Charles
Title: Re: Fox 35 Mufler
Post by: Jim Thomerson on September 16, 2012, 11:12:00 AM
I have posted elsewhere photos of my smallest, lightest, and least effective muffler for your style Fox stunt 35.  It is a piece of tin with holes for mounting screws above and below.  It covers about 1/4 of the exhaust.  It has a tab bent into the exhaust to make sort of a pocket with the vertical brace in the center of the exhaust.  There is a pressure tap into the pocket.  It works very well for giving muffler pressure, but does little to the sound. 
Title: Re: Fox 35 Mufler
Post by: pmackenzie on September 16, 2012, 05:15:07 PM
Not sure if this is what your referring to?

Charles

More like this I think  :)