Projects An Amateur Chops a Brookville Coupe & More

That's scientific exhaust fab - super-sano, amazing work!

 

Thanks SDS.
I made a lot of progress on the exhaust, it's basically done I just need to do the final welding and hanger brackets.
I needed to run the exhaust between the ladder bars and driveshaft to be in a better position to go up and over the rear axle housing.
The best place to cross over to get between the ladder bars and driveshaft was just behind the front mounts for the ladder bars.
I was able to sneak under the bars with just about 3/4" clearance. Not much space is needed because the up and down ladder bar travel at the front mounts is minimal.

After crossing under the ladder bars I made a rolling 45* offset to raise the mufflers above the bottom of the bars to sort of hide them. I used v-band clamps on each end of the mufflers.

I needed an exhaust hanger on the muffler outlet so I added 1" tube steel crossmember across the frame that I'll use to mount the hanger bracket.

Up and over. I had just enough room to leave enough space for full upward travel of the axle housing and have about 1" clearance to the floor.



The hard parts done, now I need to weld everything up. I used a total of 18 weld elbows and about 13 feet of tubing on this which leaves me with 52 welds to make.
I also have to make some changes to work that has already been completed. While working on the exhaust, I found there were a few clearance issues along the way that I had overlooked. I'll be working on fixing those issues next.

 

I finished up with the welding on the exhaust, here are some shots of the welds and the complete system off the car for a better view.
Here is the V-band clamp.

Some tubing welds. I butted the joints up tight with no gaps and was able to fuse weld them without using filler rod. Since this is stainless tube, I purged the inside with argon gas to stop any weld contamination and keep the inside looking as clean as the outside.

Here is the finished exhaust. Really satisfied with the way it turned out. I still have to add the hanger brackets.

 

Outstanding! I am envious of your fabrication skills!

 

Perfect!

 

Beautiful welds! That system should work and sound as great as it looks!

 

You sure do some really nice work . Great job.

 

Thanks guys.

 

WOW that is some GREAT welding and great looking system.

 

Dang.
I might have to sell my welders now

 

Mine don't look that beautiful either Anthony. But that is OK as it gives us something else to strive for. Perfection. Bcap55 has perfected it for sure.

 

I found these stainless steel exhaust hanger brackets at Summit, they come already notched for the size tubing I'm using. They are easy to install and have a nice clean look.



I wanted a more finished look for the tubing ends, so I machined a pair of fittings that slip into the exhaust outlets.

 

Be aware, those blue grommets can melt if too close to heat. Keep an eye

 

I had problems with those hangers. The plastic cold flowed and ended up with metal on metal. Changed like he'll when I went over a bump. I like the way they look but did not have good luck with them on my application. Good luck!

 

Those grommets are supposed to be made of high temp silicone rubber, but I'll have to wait and see if they hold up. I'm worried more about the front hanger since it will see the hottest temps.

 

I ran into a problem with the exhaust system at the jump up over the axle housing on the drivers side when I was laying it out. No matter what I tried, I could not fit the exhaust between the panhard rod and axle housing. Since the panhard bar and axle housings move back and forth through the suspension travel, I could fit the exhaust to miss either the panhard bar or axle housing but not both as the rear end moved up and down. I needed more room in the area shown in the photo.

The rear end wasn't going to move back, so the only option was to move the panhard bar forward. Here is the chrome center section mount that needs to be changed to move the bar forward.

I didn't want to cut up the nice chrome brackets so I made new ones out of 3/16" steel plate. The offset in the front piece will move the panhard bar forward by 1/2".

Now I have good clearance for the exhaust throughout the full range of rear end travel.

 

Fuck. I've used a few of those silicone things in my 32 coupe that's in progress. Mine are red though (and didn't come with the metalwork). I hope that makes a difference .

Chris

 

I checked on the McMaster-Carr website and they have high temp silicone grommets that are rated for up to 500 degrees F. (260 deg. C). If the rubber grommets that came with the hangers are rated the same, they might be ok.

 

Just run long enough to break in the cam. This is in front of the muffler, the next 3 in line are fine. So far.

 

Plastic is molded by melting it and squirting it into a mold under high pressure, then cooling it. This is plastic, albeit with a higher melting point. As it gets heated up, it loses strength and flows. The weight of the exhaust causes it to flow. Soon, you will be metal on metal.

They did not work for me and I'm pretty sure they aren't going to work for you. With all the care and precision you've put into this fabrication, I'm guessing you won't be happy with it clanging around every time you hit a bump nor with the resonance that will occur with metal to metal. Time to seek out another alternative, IMO.

 

Well looks like I'm going to have to rethink this. The hanger closest to the motor probably won't survive very long, so that one will have to be changed. I think if the grommet is moved farther away from the exhaust pipe like the last hanger at the back, there is a better chance that the grommets won't melt. I'll play around with some ideas and come up with a better design of the front and middle hangers.
Thanks to everyone who responded with a warning about these hangers, I would have left them as is and most probably been very disappointed after the car is finished and find out that I would have to make changes then if no one had said anything.

 

I am trying to remember where I got some High Temp grommets I used on my last build. They replaced the ones like you have and have held up for 3000 miles. At my old age it takes a while?

 

Me and a few others would be happy to know where you got those grommets.

 

McMaster-Carr has high temperature grommets which are for temperatures up to 500* F
https://www.mcmaster.com/high-temperature-grommets/

 

While we are on the subject of reworking things, here is another area that needed to be modified. When I was laying out the exhaust system and checking the clearances at the rear axle thru it's full travel, I noticed that the quick change center section and pan hard bar mount were higher than the top of the frame rails at full up travel. This meant that they would hit the trunk floor with the suspension fully compressed. I never thought about checking for this. Oh well these are mistakes we amateurs make .
I never liked the pocket I made in the trunk floor to clear the jump up on the coil over mount cross bar.

So I decided to eliminate it and modify the center of the trunk floor to clear the cross bar and rear end center section all in one. Here is the area that I cut out.

You can see how far the pan hard bar mount and center section stick up above the floor.

My plan was to raise up the trunk floor 1". Here is the piece mocked up in place.

Luckily I saved the piece of the floor I cut out for the original pocket, and was able to weld it back in to save the beaded detail.

I cut out the rear section of the floor and flattened it out a little and tacked it on.

Here is the center floor section with the raised sides welded on.

Tacked in place.

All welded up.

This is rework that I was happy to do, it eliminated that ugly hump that was there before and now looks much better. I wish I didn't have to change the nice flat floor that came with the car, but now it will be easier for the upholsterer to blend in and hide this raised section with the rest of the floor.

 

Apologies for my involvement in this wonderful thread taking a bit of a left turn as regards the exhaust bushings. The red ones I have came from Summit and are supposedly high temp items. I melted one when welding the stainless mount too close to it. Lesson learned. Subsequently I've had the motor running upto temp and idling for a while. Brand new 406 smallblock, dynod at a shade under 500. When messing with the timing I had it horribly wrong and before I could blink I had the ss headsers glowing red and a bit beyond. A real oh shit moment. Thankfully no harm done as far as I can tell but I know the exhaust got very hot as the stainless tube has turned golden for a couple of feet or so. And the good news is that the red bushings survived despite the mounts being quite short. Im not a fan of them being red and I see that some black ones are sold as Peterbilt exhaust mounts, but they might be for stacks which I guess might not get overly hot?

My car has any number of similarities, but my execution is somewhat lacking in comparison! I have a Champ qc rear and my trunk floor is modified rather like the now remodified one here!

Anyway, back to the scheduled programming!

Chris

 

They get hot enough to burn you but will not light a cigarette like a gas engine exhaust will.

 

I don't know what to do now.

 

There are no "pretty" solutions that I have found. These are the best type at isolation and durability. You can use 3/8" SS rod in place of the carbon steel and paint the brackets. If you find something better, post it up. I'm interested.

https://www.summitracing.com/parts/wlk-36516

 

I'd like to stick with the grommets and make longer brackets on the exhaust pipes to move them farther from the heat.