Heres my small contribution to the tech week. I hate when exhaust swings and knocks everywhere and I couldnt find good supplies enough so I decided to make some of my own. My current project is my second car with this kind of fastening and it works very well. So in the first photo there are shown pretty much all parts you need to make one hanger. And all those parts can be bought from your local hardware store. This second photo shows the finished product. It has been welded next to the cross member. The trick is that pipe is not hanging but it lies on the rubbers, which makes the structure extremely rigid. The third photo shows diversity of these things, the hanger has been welded next to Model As rear member (just because there was a good space for it) and it supports very well the transverse movement of rear axle crossing. Theres only one flaw in this system; there must be some space above the pipes to move them upward when removed. However this structure doesnt need any space but you can mount them as high as you want. So if you want to build a removable exhaust you may replace the fixed bolts with bolts going through punched rubbers. So that's all folks, hope some of you can find this tech useful. --mika
That is slick. I have mounted any number of components that way, but it never occurred to me to mount the exhaust in that manner.
I've mounted some similarly, but with my upcoming build, I'm going to try using old connecting rods as hangers. I also like those previously shown in a different post/thread where someone was using a pair of 45 degreed rods as column drops. The triangulation would work wonders and hold the pipe tight in place. Seems like he told me they came out of old Triumph motors, or possibly 8N Ford tractors.
I did pretty much the same thing, except I only mounted the pipes at the rear crossmember as they go over the rear end. Haven't had it running yet, but the rubber mounts look like they are going to work well - there is enough movement to absorb the engine vibrations, but they aren't going to move around too much and bang into anything.
Nice simple tech - I too use the rubbers that way up, with various brackets to suit. Here's my tech tip re exhausts. If you are making the system while the body is off the frame, (which is the nicest way there can be of doing an exhaust system) make sure the parts can be removed and refitted when the body is on. On my 34 I couldn't remove the rear half system with the body on - whoops!. When I fitted the baffled headers I could only remove the front part of the rest of the system - the rear half just stayed in there not connected to anything. Mart.
Having worked on old rusty exhausts (result of living in the rust belt) I would suggest one small change to your system. Mount the exhaust with a standard clamp - weld your plate to that and keep the rest the same. I suggest this for two reasons - I have noticed over time that those small welds on exhaust pipe seem to crack over time. Second if it did need replaced for any reason you could simply unbolt it - no fuss no muss. Please don't take it as being critical of your design - just me thinking out loud. FWIW
If my memory serves me correctly the 9n,2n,8n tractors did not have rod caps at a 45 degrees to the rod. I could be wrong the last ford tractor engine I rebuilt was in 1980. Although i rebuilt at least 100 of them it was a long time ago and I have sacrificed alot of brain cells to keep the breweries of America in business.
That looks really nice. REALLY nice. On my stuff I use the late model hangers, where there's a rod attached to the exhaust and one attached to the body, and both go thru the rubber hanger. Super easy to fab and mount since you're just bending 3/8" rod, and have been extremely reliable. But here's the tech-week worthy tip for this style- double up the biscuits on one of the mounts. That way if you have a failure on the road, there's already a spare rubber biscuit on the car.
I work for an OEM exhaust manufacturer and pushed a light weight exhaust system for a few years. The reason your welds crack is the expansion of the pipe with heat. It will expand differently than the cooler top section, putting stress on the welds. The second reason they crack is because the pipe expands lengthwise as it heats as well, it can grow quite a bit as you drive. 1/4" is not uncommon. This causes binding in the system and tries to blow it apart. You might want to look at making it so your exhaust can GROW as it heats up, in other words, slide on those rear mounts. Nice work, though. It took a team of engineers to come up with that and they still haven't gotten it completely right!
Nice work! One of the best OEM hangers I've seen is the ones that Dodge used on the old Dart tailpipes. Simply a sort of Z shaped metal bar that slipped into relatively small slotted rubber frame mount and one clamp helded it on the pipe. They have very little room to move much side to side but it could slide during expansion and contraction. Stu
Check out these factory exhaust hangers for a '76 Malibu. The 35182 rubber isolator fits into the 35181 mount (which is shown upside down in the picture). Then the tongue of the 35662 hanger slips into the rubber isolator. The hanger is held to the exhaust pipe with a regular muffler clamp. It's something like $5 to buy all the parts. If you look thru GM cars from similar years, there are a few variations of this design that will interchange. The Walker diagram comes from RockAuto.com
Thanks for response, good to see some discussion here. Good points from all of you. Simonsez makes my work look little rough but that´s a good example what you can build with the same principle, only make it smoother and more beautiful if you want to. IMO the best part of this system is how well it really works, pipes truly stay in correct position! Danimal wrote about cracking, that's a good point and crossed my mind too, but I trust in flexible rubbers, and no problems so far... Welding plates on standard clamp and keeping the rest same is a good idea too. Evolution...? --mika
That brings back memories! I used to do a lot of these exahaust in the early 80's That 35662 bracket was great as you installed it on the muffler first and slipped the whole pipe and muffler on and it held everything in place and freed up you hands to install the tailpipe etc. Stu
Take a look also at the GM trucks. The pickups from 88-98 had a slip tongue just like the ones on the Malibu above. With the miles you're going to drive (I wouldn't expect more than 30k without digging into it again) you probably won't have too much issue with welds cracking. I also doubt you'll see the thermal cycling most cars do today, especially with all of the body mouldings that are out there. We've had to put heat shields on spare tires on some of the minivans in GM because there just isn't enough air flow under the car to dissipate the heat. We are 2" away from the tire and you can smell it on a hard drive test. Mmmm. Bosal did a paper at SAE (Society of Automotive Engineers) a few years back. The discussion there is a firm mount up front and then a mounting scheme in the rear of 2 point rubbers. There is a rubber puck with two holes in it, basically a top and bottom. A rod is mounted under the pipe and the ends go through one of these pucks on each side. The top hole is a body mount side. It is rigid like you want but it allows the thermal expansion to 'swing' the mount fore/aft. I'll see if I have that paper still.
Not the best picture but it is from the Bosal website. http://www.bosal.com/international/?open=pa-exhaust.htm&lang=english
Asshat question: What are the biscuits in the picture? Are they molded onto a stud, or do they have separate studs out the top and bottom for ultra-vibration-dampening? -bill
Separated studs, molded onto rubber, typically used under the radiator and thinks like that. They are sold as exhaust hangers sometimes but they do not work well when hanging.
I made something similar, only I used 1/4" stainless bar stock and some stuff called RhinoHyde for the spacers. Very stong. I can hang from the pipes with the truck up on a lift (I'm around 265 lbs.). I'll try to get under it and take a few pix to post.
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