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Ideas for bending exhaust pipe

44K views 22 replies 16 participants last post by  1971BB427 
#1 ·
Hello. I am getting ready to put my exhaust on my 81 El Camino. Has anyone tried bending 2 1/2" exhuast pipe with something made at home. I am trying to make my own custom exhaust. I was thinking about putting sand in the pipe and cutting a piece of wood in the shape of a half moon to bend it.
Does anyone have any other ideas?
Rob D.
 
#5 ·
Yeah, making an exhaust system for a car where systems are available ready made is fighting a loosing battle. If you do want to continue this is what I was talking about with "U" bends. You cut them and rotate them to make the bends you need. My brother did the system in his roadster and it worked out very cool. But again, if you can by a system ready made you are probably going to save money.



Google exhaust U bend and you will get pages of sites.

Brian
 
#6 ·
Surely there is an exhaust shop that would bend your entire exhaust sytem for you. Usually, the pipe used for bending is thicker than the stuff that autoparts or whoever sell. Time you buy the pipe and monkey with it (your time = $$) you won't come out ahead dollar wise. Plus a good exhaust guys pipes will be right, no hanging or don't fir stuff.
 
#7 ·
I don't think I will try bending it myself. I have a set of dynomax headers on the car now. They have according to my dial vernier caliper 1.610" o. d. on the primary tubes. The four primary tubes feed down into the collector. I am not sure what the name of this next piece is, but it is flared on one end(bolts to the header), about four inches long, and is to be welded to the rest of the exhaust system on the other end. This piece that I am talking about has 2.420 i.d. and 2.520 o.d. What size pipe should I make the rest of exhaust system (2.5", 3.0") and where should I put the H pipe and muffler if I want them to end right in front of the rear tire on both sides. Will not be running converters.
Thanks for any and all responses.

Rob D.
 
#8 ·
newdad1 said:
I don't think I will try bending it myself. I have a set of dynomax headers on the car now. They have according to my dial vernier caliper 1.610" o. d. on the primary tubes. The four primary tubes feed down into the collector. I am not sure what the name of this next piece is, but it is flared on one end(bolts to the header), about four inches long, and is to be welded to the rest of the exhaust system on the other end. This piece that I am talking about has 2.420 i.d. and 2.520 o.d. What size pipe should I make the rest of exhaust system (2.5", 3.0") and where should I put the H pipe and muffler if I want them to end right in front of the rear tire on both sides. Will not be running converters.
Thanks for any and all responses.

Rob D.
The piece you are referring to that the rest of the system welds or clamps to is the collector reducer, also known as a street hook-up(Hooker headers term). Yours are for 2.5" OD pipe, and the 2.5" size should be fine for you.

Why dump the exhaust at the axle Jethro-style?, it will resonate badly inside the car and soot up everything under the car, when good mandrel bent kits with tail pipes are cheap and easy to get from Jegs or Summit? These kits are better than average tubing, include everything, and both places have a good selection of H and X type crossover pipes. The crossover should be placed as close to the header collector as is physically possible (Allow for trans removal at a later date)
 
#11 ·
Mike H said:
Have fun getting by the trans crossmember on the drivers side. I have built quite a few crossmembers out of 1 5/8" tubing for the G bodys so they can get real dual exhaust on the car without going under it or bith pipes on the pass. side of the car.
The 64-72 Chevelle crossmember fits these cars very nicely(I've done this) after trimmimg a little length (less than an inch) off each end and redrilling the mounting holes. Bolt it up to the tranny mount then and square it up to see where you need to drill the new holes in the frame. This crossmember has two humps for dual pipes, and I believe the 73-74 Chevelle/Monte Carlo member could also be made to easily fit.
 
#13 ·
I took mine to a local shop and had them do some bends.. they didn't even charge me.

Problem with this method is if the bends don't turn out perfect it requires tons of trips, or you do what I did, and cut small angles in the pipe with the bandsaw and weld it back together. Simulated bends, I guess :)

Doesn't look the greatest but whatever, it's just a pickup.
 
#15 ·
pipe bending.

Some of the better equiped shops have a cnc pipe bender, If they have the program to bend your pipes. I saw a U tube a while back on bending pipe. The guy used several layers of duct tape on the end, then got on a ladder and used a wood closet hanger pole and WET sand and packed it in tight then duct tape layers on the top end. He then used the HF pipe bender. 50 plus years ago I tried the packing it with dry sand, and heating with a torch and it didn't work . We were putting twin pipes on a chevy 6. I bought a new stock pipe then made the necessary cuts and welds to have the second pipe fit. easier than building the whole thing with U 's and straights. 40 years ago we did an all nighter in a muffler manufacturing factory in the bad area of detroit. building a new exhaust for the 427 Cobra that won the 2009 optima That exhaust has since been replaced, . I used 1/8 gas welding rods to get the pattern shapes we needed then loaded the pipe and manually bent and rotated the pipes to get all 8 pipes bent.
 
#17 ·
71haulnazz said:
You can buy a tube bender at Harbor Freight for like $100 bucks. Just pack with sand and bend away. Real easy.
Those are PIPE benders. A totally different beast. They do bend tubing, but will kink it as the dies aren't the same as pipe is bigger OD. For tubing, some work on the dies is needed or the tube must be packed with sand.
 
#18 ·
tubing bender

I worked at a company that made oem exhaust systems , mufflers and Misc parts for Harley, Our cnc bender used a mandrel (egg shaped internal dies on a SS cable) that was pulled thru the tubing as it was bent to give the smooth wrinkle free surface. a lot of the tubing had to be annealed and the weld in the correct position to get good pieces.
 
#20 ·
timothale said:
I worked at a company that made oem exhaust systems , mufflers and Misc parts for Harley, Our cnc bender used a mandrel (egg shaped internal dies on a SS cable) that was pulled thru the tubing as it was bent to give the smooth wrinkle free surface. a lot of the tubing had to be annealed and the weld in the correct position to get good pieces.
That was worth resurrecting this old thread, VERY intresting.

Brian
 
#22 ·
Yes!! I know that this is an old thread, but since no one had posted photos of a home welded up exhaust, wanted to show one for 'posterity' and the next guy who looks.

Built from:
2.250 tubing - a 10/12 foot length
U and J bends from Summit
SS clamps and hangers
Flowmaster mufflers
~$225 for all the above
Then MIGed together



The only 'pro' done pieces were the clamped pipe seen at the H pipe and that was to 'blow out' the pipe size for slip fit for ease of disassembly if ever needed. That cost me the price of a coffee and donut break for the three guys in the Midas shop.

Dave W
 
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