Exhaust pipe drivers side routing

36coupe

Well-known member
I think I’m too close to the steering box and clutch arm. I have to grind the tacs off and do some minor adjustments.
I plan to clear the steering box by 1-2”. Is that enough?
I don’t have the clutch hooked up as I don’t have the 39 clutch arm so I’m not sure how far the pedal will travel.
Will it travel all the way to the notch in the frame x-member?
 

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The pedal will hit the exhaust pipe. Make a mark on the pipe where it hits, heat that spot cherry red, then slam that pedal into the pipe. Just a little more with a ball peen and you’re done.
 
The pedal will hit the exhaust pipe. Make a mark on the pipe where it hits, heat that spot cherry red, then slam that pedal into the pipe. Just a little more with a ball peen and you’re done.

That’s exactly what I done on my 40. That was 30 years ago. Still working to this day.
 
I have duals on my 38 but I didn't build it. Clears the pedal and mc, have you tried the pedal. I think what you are doing looks great. Not a lot of room. Nice work. 2" pipe?


Maybe take it closer to the frame then out. or down and out.
 
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I have duals on my 38 but I didn't build it. Clears the pedal and mc, have you tried the pedal. I think what you are doing looks great. Not a lot of room. Nice work. 2" pipe?


Maybe take it closer to the frame then out. or down and out.

1-3/4”, over the years I have bought ‘box of bends’ and fab my own. The pipe is all mandrel bends, although I made a mistake and didn’t order aluminized pipe last time and is very thin. Prepping and belt sanding the joints are critical to good fit.
2” would be very challenging hitting the holes in the frame just right to ensure no chance of rattling off the sides. I went back out after supper and if I use 2- 45° as soon as the pipe exits the hole I should clear the pedal.

My big concern is being too close to the steering box which I am right now. Could exhaust pipe heat effect the box internals?
 
1/2" might be ok but more would be better.
1-3/4" is more than enough for one side of a flatty. Full race setups might need more, but 1-3/4" is plenty for 99% of applications.

I dented the pipe on my 40 coupe years ago, just like as described above.
 
Exhaust theory is quite an interesting read. Mark the pipe with the heat stick and where the heat stick didn’t burn off install a crossover. Next was to use one size larger pipe after the mufflers. I think the theory is as the gas cools it slows down so going to a larger pipe allows it to exhaust better. A smaller diameter close to the engine creates a higher rate velocity, More back pressure and better bottom and response. I like the exhaust note of a smaller diameter pipe. If one 1-3/4 pipe is good enough for a stock engine in two 1-3/4 pipes would be all you ever need for just about any flathead
 
One weld left some paint and exhaust clamps. The pipe from the mufflers back where bent on a pipe bending machine coping an original pipe. I used 4 welder series exhaust hangers and 2 generic type hangers. The glass packs are walker 2”.

I went wide around the starter to keep the heat away and make it easy to change if needed.

Pretty happy with the result. By the time I finished I think I could do it way better a second time.
I find it quite satisfying fabricating custom pipes.
 

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Good job. It will sound great through those small resonators. That's what I have on my coupe and sedan.
 
I had 2" pipe and went with 1 3/4 later. Like the sound a lot better now. Nice crackle. Have resonators now but I might go with some mufflers soon as I would like it quiet. Everyone else tells me it sound great though.

I used fenton exhaust manifolds on the 38. So the pipe runs after the steering. The fenton runs very close to the steering box. With fentons I had to dremel a bit off the manifold to create a 1/8" / 3/8" clearance. They are very thick. No issues with heat and the steering box. Can always use cornhead grease in the box.


Nice work!
 
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