Has anyone had experience (good or bad) with bending up exhaust pipe with a hydraulic or manual bender?? Would appreciate some experienced reports....and what device did you use?? How many degrees can you do without crushing the pipe?? Thanx in advance.
If you're eyeballing one of those inexpensive pipe benders from HF or others, forget it. Those will just crush thinwall exhaust pipe. To even attempt it, you need a bender with a 'follow' shoe (so both sides of the pipe are supported) but the bend radius will be huge; 16" or more. Without the proper bender/shoes, don't expect to get more than about 10 degrees, and even that is pushing it....
It's much easier to buy mandrel bends and weld them in. The non mandrel benders can be found at any muffler shop and do a great job of narrowing the pipe. The mandrel benders are harder to find local but the bends can be sent anywhere in the world. The problem with benders and exhaust tubing is the wall thickness is too thin and kinks. I suppose you could fill it with sand ( poor mans mandrel) and bend it.
we bent some with a low buck tool bender used for roll cages , but you have to fill the pipe with sand or it folds it up like paper and use th eright pipe die ( which are electric conduit bender dies ) . but the nice thing it don't wrinkle or shrink like a standard machine style one .
Here are a few of our benders, but at a couple hundred thou a piece, these are not for the average shop; As mentioned, the problem with exhaust tubing is it is very thin wall and will crush or collapse with non mandrel benders. Some folks have had limited success with filling it with sand and plugging the ends, but it is still a crap shoot and can be tedious. Buying mandrel bends and then welding it together is the best way
I've found that starting with an "exhaust kit" for a factory car has always been cheaper and easier than any other method. On my present project I ordered a kit from Jegs that was a "header back" kit for a late 60's Chevelle, without mufflers. The whole 2.5" kit was $159, and came with 8 U bolts, 4 poly hangers, and a couple rubber strap hangers. I didn't use any of the U bolt clamps, but most of the rest. I simply picked pieces from the kit that were closest to what I needed and then cut sections out of others to tack in until it fit my project. It took very little modification, and made a clean looking system. Had a couple bends leftover that I didn't need, and ended up with a full length 2.5" exhaust from my fenderwell headers to the rear bumper. Only took a day to tack it all up, and then weld it solid and hang it.
I did the same thing for my O.T. daily. Bought an inexpensive mandrel bent kit for a late Mustang, some cut-and-turn, a few extensions, and it tucked right in. That's my go-to plan now for any exhaust work. Look at ready made kits that have the general routing you want, and make it fit.
My friend's shop was too busy for me to tie up a bay, so, I made a dual exhaust pattern for my '56 Buick out of 1-1/2" PVC and took it to the muffler shop and duplicated it there out of 2"pipe. Much cheaper than one of those pattern kits. I think it cost me 4-5 dollars.
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