Building exhaust flnge from 7/8" Grd8 washer and piece of fork tubing

Nothing fancy here and I haven't taken pix of it since some more cleaning up and the header pipe being brazed to flange tubing, but I just thought I would share some pix of how you can make a nice exhaust flange from a washer if you have the tools and want to take the time, I wanted the "Taffy Bike" to have a large unrestricted exhaust since the mods I have done to its engine will allow it to get so higher than normal revs, the header pipe has a 1" ID and is currently 18" long, I will likely reduce the length to 14-16" if I have room to go that much shorter and still be able to mount the expansion pipe where I want it.

These pix are all of things in the rough and honestly I didn't do a lot of cosmetic clean up since the header pipe from flange to chamber will be wrapped in exhaust wrap so none of it will be seen anyway, but is is cleaner then seen in these pix now and has been sprayed with hight heat flat black paint.

bairdco said:

y'know those bolt through frame adapters that come in the kits? the one where you're supposed to dri a hole in your frame to mount your engine?

drill the center hole bigger and boom, instant exhaust flange.

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Thanks bairdco, I think I have one of those drill through the frame mounts, thats a great tip, Ill try to find it and try that mod out, little things like that are good to know for repurposing junk parts like those type mounts.

bairdco said:

they also work as intake flanges on motors with the larger intake.

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More good info, thank ya sir...... these little things sure can help people out sometimes and are always welcome to us hacks and tinkerers who just enjoy the process of taking what we have and making it work for what we need.

Thanks bairdco

YesImLDS said:

That's a pretty beefy pipe diameter you got there map! and a cool idea! I noticed when I got the exhaust manifold when I bought my SBP expansion chamber that it matched up to a door lock faceplate!

What kind of exhaust you gonna run on that beast a VW bug exhaust!? Probably would bolt right up to that exhaust piping!

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The pix make it all look way bigger than it is, its only 1" ID, but it does look huge in those pix, I have a moped expansion pipe I got from treatland.tv a couple years ago that has been sitti g in a box, Im not sure the stinger pipe running through the silencer is as big as it needs to be, but Im gonna try it on the Yellow "Taffy" bike and see how it runs, I thi k the chamber will suit my needs or wants but I'm not so sure I won5 need to cut the silencer off and braze on a large ID stinger to get the flow where I want it.

I have one of the big fatty snake looking pipesI rigged up last year, and its an under performer do to the small 3/4" ID header pipe and maybe even because the exit is a bit restrictive also.

Ive found that one of the key things to higher rpm potential on my engines has been to get the exhaust right, an expansion pipe is not needed abut good if its done right, an expansion exhaust thats to restrictive on either end with have worse performance that a straight pipe or even a gutted out and modified stock type muffler/exhaust, Ive yet to have m6 fastest bike do its top speeds with an expansion pipe, all my top speeds have been done with very free flowing exhaust that I rigged up myself, problem is that they are very loud which makes no difference to me where I live, but for city people that kind of exhaust can draw negative attention to our bikes.

Im not shooting for a top speed personal record anymore so as long as I can get a couple of my bike to comfortably cruise at 40-43mph on the flat with a 32-36T on the rear Im happy, Ive done 50+mph on the one bike, done 48mph on another and Im good, I was inspired by bairdco way back when I got i to this hobby to build an engine that would get me to or over the 50mph mark, I did it and now Im happy at 40mph-ish for a top speed and a comfortable cruise speed of 35-40mph if I want it.

The right balance, the right jug, good clean ports, good compression, well tuned carb like even the little NT or NT Speed carb,the right gearing and a good free flowing exhaust will get what I want done with my bikes and thats what Im shooting for each time I put one together, having a good crankshaft balance is a huge part of all this, if someone has a horribly balanced crank all the other things dont mean much since the higher rpms will just help the engine grenade much quicker.

Trey said:

Need it. Make it. Got it.

Lookin good Map!

Thanks for sharing that. I don't have a welder, but I bet it would only cost a couple of bucks to have that done at a shop.

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Yep and for most of what I do, I dont use my welders, I use my torch and I use brazing rod or just a cleaned up cwire coat hanger to fuse many of these scrap pile projects together and just basic i expensive type shop tools formost of the work, I dont try to get to fancy with most of it, I just make up something that will work with what I have or can find at tractor supply or a local hardware store, I have a limited amount of time to spend on my bikes because of other responsibilities, but I do what I can as cheaply and quickly as possible to get what I want or need.

I like to do things that way on my bikes and then post it here hopi g to help someone else, yeah many fancy builds and parts get shown on here and its all great, but amny people have limited resources and live in an area where they have to do what they can with limited space and tools, so its good to show the simple ways to do somethings with simple parts and pieces also, I have a lathe and mill, welders and a pile of all sorts of tools but I like to keep itsimple and Im no professional machinist either, just a tinkerer so I use simple inexpensve methods as much as possible, I would rather make somthing than buy it if possible even if mine aint the pretty girl in the room when Im finished with it.....lol!

I love to learn new things, and so many people here have unknowingly increased my knowledge many many times on this forum, I try to keep it simple most of the time since I dont have the time to put into a long drawn out project as far as the parts and pieces are concerned and I try to make something I already have laying around work for what I need many times, doesn't always work out but when it does I always feel purdy good about it, to me that is part of the fun.

Anyone can order a part and bolt it on, but the fun of making the part myself when I can is what a tinkerer like myself enjoys.

, Map

Yep a flat washer can be used to make intake or exhaust flange, a long while back someone else on here did the same for an exhaust flange also if I remember right.

I've found the exhaust is a huge factor in whether a CG build will have good power overall or not no matter what else is done to it, one of my engines that would hit 48mph with a fairly straight through exhaust would only do 37mph when I put a more restrictive expansion pipe exhaust on it, the right exhaust on these little engines makes a good bit of difference especially when other mods have been done.

Some engines dont run that good no matter what you do, but even a good engine can be choked out plenty easy with a restrictive exhaust even if it has an expansion chamber.

Expansion chambers dont mean squat if it isnt at least close to being right and very free flowing in my experience on my bikes, fastest top speeds Ive ever done on my bikes were without expansion chamber exhausts, Ive yet to have the right one set up right, but Im hoping the next one I do will be better since Im using a different pipe and going to more pains to hopefully get it to perform like I want it to.

2door said:

Just to toss out another idea for repurposing stuff. Here's the exhaust flange on the Norton. I use the male and female parts of an 'explosion proof' electrical conduit fitting. The male section is welded to the flange that I made and the female part is welded to the pipe.
This allows removal of the exhaust system without disturbing the flange to cylinder gasket seal. The big nut tightens the two parts together and doesn't leak.

Explosion proof electrical fittings aren't something you'll find at Home Depot. You'll need a friend who is an electrician or buy them from a commercial electrical supply house. They're used when running electrical in an explosive atmosphere, like paint booths or flammable material storage areas.

Tom

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Looks good Tom and thats a good tip also, so many creative ways to do things with our bikes and thats what make it fun to me.

Springfieldscooter said:

Great job map! Wish you would mass-produce a few and sell one to me!

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Thanks for the comment Sscooter, well its a time consuming process to make this kinda part with simple tools and honestly I have little time to work on my bikes that I haven't even done another single thing to the bike this flange was for since making it, its painted and bolted to engine now but thats as far as Ive gotten.

At some point in the future I have thought about making some parts up like this for purchase so someone who may not have the tools to make it could get one, but for now the way I work and with all my other projects I just dont have the time.

Im surprised we dont have others already making some exhaust parts and pieces for these bikes other than what we've had available for a long time now.

The SBP exhaust is better than a unmodified stock pipe when plumbed right but still not all that good for a more modified engine.

I have some ideas I hope to work on when I have time that may give another option for someone who wants a good free flowing exhaust, but it will be a while before I have time to work on it.

Peace, Map