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Engine basics => Engine set up tips => Topic started by: Robert Zambelli on June 30, 2010, 05:31:30 AM

Title: Interesting Fox tongue muffler
Post by: Robert Zambelli on June 30, 2010, 05:31:30 AM
Found a bunch of these in the old junk box.

Anyone ever try one??????????????????   ???

They are from Fox, for the 29 & 35 but there are no part numbers.

Bob Z.
Title: Re: Interesting Fox tongue muffler
Post by: john e. holliday on June 30, 2010, 07:42:20 AM
Must have been from when he was still experimenting.   H^^
Title: Re: Interesting Fox tongue muffler
Post by: Larry Fulwider on June 30, 2010, 08:36:33 AM
Bob --

How wide are the small slits for the exhaust? In the pic, they look like only .015 or so, totally inadequate. The mounting screws look odd, designed to countersink, with no matching countersink bevel in the muffler.  ???

Are you making this up just to confuse folks?    <=

       Larry Fulwider
Title: Re: Interesting Fox tongue muffler
Post by: Robert Zambelli on June 30, 2010, 09:05:03 AM
Good call, Larry - the slots are actually .018.

The muffler was packaged wrong from Fox. I flipped the baffles over and you can see that they are indeed countersunk.

No, I'm not making it up!! Check out the photo of another one, never opened.

Bob Z.
Title: Re: Interesting Fox tongue muffler
Post by: RandySmith on June 30, 2010, 10:54:18 AM
Good Price !!

Randy
Title: Re: Interesting Fox tongue muffler
Post by: Brett Buck on June 30, 2010, 11:37:06 AM
Quote from: RandySmith on June 30, 2010, 10:54:18 AM
Good Price !!

    Just looking at it, it appears you get what you pay for!

    Brett
Title: Re: Interesting Fox tongue muffler
Post by: dennis lipsett on June 30, 2010, 12:56:42 PM
I remember that thing. Even saw one of them at work. Horrible back pressure. However it did reduce the worlds supply of Foxes in relatively short order by frying it.
Dennis
Title: Re: Interesting Fox tongue muffler
Post by: RandySmith on June 30, 2010, 01:11:39 PM
Quote from: Brett Buck on June 30, 2010, 11:37:06 AM
    Just looking at it, it appears you get what you pay for!

    Brett

Ya mean that maybe all its worth???? H^^ S?P
Title: Re: Interesting Fox tongue muffler
Post by: Russell Shaffer on June 30, 2010, 01:14:45 PM
I bet they would be OK if a guy did some drill press work on them.  Big Iron has mentioned Fox "horseshoe" muffler brackets. 
Title: Re: Interesting Fox tongue muffler
Post by: Brett Buck on June 30, 2010, 02:04:25 PM
Quote from: RandySmith on June 30, 2010, 01:11:39 PM
Ya mean that maybe all its worth???? H^^ S?P

   I don't know for sure. What's the scrap value of aluminum theses days? Figure the screws cost about about 1/2 a cent a piece, probably about the same aluminum it would take to make 20 pop cans.

   On the other hand, after the engines seizes from overheating, it *will* indeed be much quieter!

   Brett
Title: Re: Interesting Fox tongue muffler
Post by: Phil Bare on June 30, 2010, 05:57:45 PM
Hi Robert, I would like to purchase one from you, they work quite nicely when massaged just right.        :-)
Title: Re: Interesting Fox tongue muffler
Post by: Jim Thomerson on June 30, 2010, 08:37:57 PM
I have had one of those go through my hands.  It is designed to fit a particular one of the older model Fox 35's which had flats on either side of the rear of the exhaust stack.  The horseshoe seats against those flats and puts no distorting forces on the crankcase.  The usual strap on muffler can distort the crankcase and cause binding.  It is actually a pretty thoughtfully designed item.
Title: Re: Interesting Fox tongue muffler
Post by: Larry Fulwider on June 30, 2010, 09:25:55 PM
Quote from: Robert Zambelli on June 30, 2010, 09:05:03 AM
. . . the slots are actually .018.

 . . .

Bob Z.

Bob --

 Ok, with three slits (correct?) each ~ 1 1/16 * .018, I get:

.057 in2 exhaust area


I have a regular Fox 35 muffler, ID of pipe ~ .355, which =>

.099 in2 exhaust area.

If the slits were widened to, say, 1/32" wide; the exhaust areas would be comparable. Not sure the flows would be, tho  ::)


     Larry Fulwider



Title: Re: Interesting Fox tongue muffler
Post by: Robert Zambelli on July 01, 2010, 06:53:15 AM
Hi, Larry - actually, the slot length is only .95, bringing the area down to .051 in2.

But, like all discussions, we can speculate all we want but the true resuults can only be determined by test.

So, I will perform one on a stock Fox 35 and see what happens. The usual - before and after, monitoring speed with a tach, head temperature with a thermocouple and run time with a stopwatch.

I do have some concern about temperature. A few years back, I tried one of those tongue mufflers with the removeable sheet metal baffles on a Fox 29. While the engine was not damaged, it ran noticeably hotter and the power was down.

Bob Z.