Exhaust My Murphy McMonkeyPatcher diy exhaust replacement - effective, ghetto AF, expansion chamber exhaust

Joined
Aug 12, 2016
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#1
originally I had the voodoo brand I think of banana tube expansion chamber that came w/ the kit I ordered (IIRC i talked the guy into throwing it in cuz I got a aluminium gt frame kit plus a relatively premium engine kit at the same time) but I had problems w/ it not quite fitting, then when i bent it around the frame for a proper fit I was a bit careless & cracked it & didn't mount it quite well enough.... it actually sheared right off where it curves around the frame & left me w/ about 6in straight pipe.

straight pipe ==> runs like crap, maybe 1/2 power, plus it sounds like an F'ing ammo dump burning down

I bought a cheap stock exhaust used on some MB's from a friend for $10, but it's so restrictive at the end that power's no better than the straight pipe (though noise sure is). It's pictured in the attachment

anyway, long story short, I took matters into my own hands & made this somewhat frightful expansion chamber exhaust. I made the main chamber part by cutting out the inside of a can of spray paint, putting it over the broken straight pipe, & bending it into the geometry I wanted as best I could. it's held in place w/ some wire & cable; a few layers of foil & muffler repair cold weld adhesive putty; and a little duct tape & hi temp engine paint. Also, there's a second aluminum bottle cut open & nestled on over the expansion chamber (steel paint can)'s outlet, w/ a tiny bit of foil & steel wool for sound dampening in the between space

I didn't really expect it to work, but now that I sealed the leaks it's giving me better performance than the often $70+ (or unavailable out of stock) voodoo expansion chamber I had originally had. power seems boosted in mid range & higher engine speed

conveniently, there's a radar speed camera on a challenging uphill by my house, so I can charge the hill & use it to gauge power output. results have been:

  • badly out of tune, or >50% choke -- won't make it up.
  • voodoo banana expansion chamber exhaust -- 24mph
  • Straight pipe -- 17mph (& lucky not to be arrested for disturbing the peace!)
  • Stock lo end replacement exhaust -- 18mph
  • Murphy McMonkeyPatcher kludge pictured below - 26mph!!
20160930_105501.jpg
20160930_105456.jpg


Clearly, the right way to do exhaust modding involves learning to weld. but I'm finding it possible to get surprisingly acceptable results w/out access to welding equipment.

Any thoughts, tips or experiences you'd wanna share on this?
 

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Joined
Aug 12, 2016
Messages
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#2
I've also been wondering if there's any kind of craft or construction product - some kind of clay, or structural concrete repair compound perhaps - that would be useful for forming & sealing homebrew exhaust setups. Anybody tried anything along those lines? muffler repair putty is kinda pricey, so if there's a cheaper option, I'm interested
 




Joined
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#6
you mean the motor drive chain? yea the chain tensioner holds it where it looks like it's almost gonna hit itself, but it seems to be good when actually driving it
 

Neptunati

New Member
Joined
Jul 9, 2009
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#7
held in place w/ some wire & cable; a few layers of foil & muffler repair cold weld adhesive putty; and a little duct tape & hi temp engine paint.
Dear sweet sweet baby Lord Jesus. Just wow. I may have to send you a proper exhaust.✉
 

Steve Best

Well-Known Member
Joined
Sep 22, 2012
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#8
so ugly it's almost beautiful, like an ocean sunfish or a narwhal? :p
I was thinking skate, sculpin, lamprey or wolf fish...

I've also been wondering if there's any kind of craft or construction product - some kind of clay, or structural concrete repair compound perhaps - that would be useful for forming & sealing homebrew exhaust setups. Anybody tried anything along those lines? muffler repair putty is kinda pricey, so if there's a cheaper option, I'm interested
Muffler cement of course, its main ingredient is Sodium Silicate or "waterglass" which is a water soluble, heat hardening compound used in food industry and a lot of things. It is used for glueing the fiberglass gaskets to the doors of woodstoves and can be bought at a woodstove store. It was also used to destroy engines in the Gov't junker buyback program. Pour it in a running engine's oil and watch it seize up.
 
Last edited:

Timbone

Well-Known Member
Joined
Apr 20, 2014
Messages
1,045
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145
#9
originally I had the voodoo brand I think of banana tube expansion chamber that came w/ the kit I ordered (IIRC i talked the guy into throwing it in cuz I got a aluminium gt frame kit plus a relatively premium engine kit at the same time) but I had problems w/ it not quite fitting, then when i bent it around the frame for a proper fit I was a bit careless & cracked it & didn't mount it quite well enough.... it actually sheared right off where it curves around the frame & left me w/ about 6in straight pipe.

straight pipe ==> runs like crap, maybe 1/2 power, plus it sounds like an F'ing ammo dump burning down

I bought a cheap stock exhaust used on some MB's from a friend for $10, but it's so restrictive at the end that power's no better than the straight pipe (though noise sure is). It's pictured in the attachment

anyway, long story short, I took matters into my own hands & made this somewhat frightful expansion chamber exhaust. I made the main chamber part by cutting out the inside of a can of spray paint, putting it over the broken straight pipe, & bending it into the geometry I wanted as best I could. it's held in place w/ some wire & cable; a few layers of foil & muffler repair cold weld adhesive putty; and a little duct tape & hi temp engine paint. Also, there's a second aluminum bottle cut open & nestled on over the expansion chamber (steel paint can)'s outlet, w/ a tiny bit of foil & steel wool for sound dampening in the between space

I didn't really expect it to work, but now that I sealed the leaks it's giving me better performance than the often $70+ (or unavailable out of stock) voodoo expansion chamber I had originally had. power seems boosted in mid range & higher engine speed

conveniently, there's a radar speed camera on a challenging uphill by my house, so I can charge the hill & use it to gauge power output. results have been:

  • badly out of tune, or >50% choke -- won't make it up.
  • voodoo banana expansion chamber exhaust -- 24mph
  • Straight pipe -- 17mph (& lucky not to be arrested for disturbing the peace!)
  • Stock lo end replacement exhaust -- 18mph
  • Murphy McMonkeyPatcher kludge pictured below - 26mph!!
View attachment 73987 View attachment 73988

Clearly, the right way to do exhaust modding involves learning to weld. but I'm finding it possible to get surprisingly acceptable results w/out access to welding equipment.

Any thoughts, tips or experiences you'd wanna share on this?
No. Just no.
 


S

Scwinn Corvette remix

Guest
#11
The paint looks horrible have you ever used tape before??? Wow man creative yes but it's like dating a fat girl its all fun untill someone sees you riding it. Was a very nice set up monarch springer fork, built in gas tank, front drum brakes.....now why on the world would you paint it like that the overstay is giving me a headache. Plus the carb might fit in the frame if you didn't have that giant intake manifold...props for creativity but man she is and ugly beast
 


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