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Exhaust routing: how close is too close for various items?

Lil'John

Former #278
Joined
May 20, 2020
Member Number
488
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Loc
Walking to the Rubicon
My exhaust is going to be tricky due to a front three link so I'm curious how close is to close for various things:
  • Manual transmission (SM465 specifically)
  • Gear driven transfer case (mid 80s Land Cruiser split case)
  • Nylon such as used in Rubicon Express joints
  • Clutch slave cylinder
For all of these, what is the minimum exhaust clearance you would do with or without a heat shield of some sort?
 
+3" with no airflow
much closer with heat shielding and airflow.
No airflow on the trail btw.

But don't take my word for it ymmv...
 
+3" with no airflow
much closer with heat shielding and airflow.
No airflow on the trail btw.

But don't take my word for it ymmv...





That's like a foot if you think about it lol.
 
My exhaust is going to be tricky due to a front three link so I'm curious how close is to close for various things:
  • Manual transmission (SM465 specifically)
  • Gear driven transfer case (mid 80s Land Cruiser split case)
  • Nylon such as used in Rubicon Express joints
  • Clutch slave cylinder
For all of these, what is the minimum exhaust clearance you would do with or without a heat shield of some sort?




The trans and the t case won't care so much but the plastics can be an issue.

What motor are you planning on running and what are your routing options?
 
The trans and the t case won't care so much but the plastics can be an issue.

What motor are you planning on running and what are your routing options?
Engine is nobodies favorite:
donor3_sml.jpg

472 Cadillac :lmao:

Here is the driver side fitment:
engineDrive1_sml.jpg


Routing options are somewhat in the air. I can't do through the hood zoomies nor can I do a true dual. For now, I'm stuck with center dump headers.
 
Since you mentioned through the hood zoomies, and because those are loud as all fuck, just add a couple foot section of tube to the headers you have and call it a day.:flipoff2:
 
Since you mentioned through the hood zoomies, and because those are loud as all fuck, just add a couple foot section of tube to the headers you have and call it a day.:flipoff2:

Add tube and run where? I've got a clutch slave and upper link mount that are going to play hell on the driver side. There is zero chance of running it down the passenger side; transfercase is "on" the frame on that side.
 
Build custom headers that dump at the rear of the motor. In my experience those center dump headers create more problems than they solve. Im not a fan at all.....
 
Build custom headers that dump at the rear of the motor. In my experience those center dump headers create more problems than they solve. Im not a fan at all.....

Could you clarify the problems?

The headers(Sanderson) on the engine are pretty rough and in need of replacement.
 
Add tube and run where? I've got a clutch slave and upper link mount that are going to play hell on the driver side. There is zero chance of running it down the passenger side; transfercase is "on" the frame on that side.


Since you haven't added any pictures of what it looks like under the rig, the only answer I can muster is, "How the fuck do I know where to run it":flipoff2:


Here's a thought..........what about a set of turbo headers? The kind that go up and forward. Then just 90 them through the hood.


500cid Caddy twin turbo headers:


HEADERS_1024x1024.jpg?v=1551674070.jpg



https://cadillachighperformance.com...g-block-t4-twin-turbo-header-manifolds-tur003


Those are kind of spendy, but sure wouldn't be hard to make yourself at all.
 
Could you clarify the problems?

The headers(Sanderson) on the engine are pretty rough and in need of replacement.

They never come out in the spot you need them to. With the collectors pointing down it requires a 90° bend right at the collector and it becomes a pain in the ass to package the rest of the exhaust around the engine, not sure on a caddy engine but sparkplug access and heat on the spark plug wires and boots sucks.

Thats just what I can think of off the top of my head. Haven't used those pieces of crap to build anything in a while so I may be forgetting more.

Headers like this are the cats meow for engine swap stuff but with that caddy engine may not be available, hence why I mentioned building or modifying an existing set.

pte-h8433_fb_xl.jpg
 
Since you haven't added any pictures of what it looks like under the rig, the only answer I can muster is, "How the fuck do I know where to run it":flipoff2:<snip>
Which puts us right back to the topic of this thread: how close can I get to things like slave cylinders, nylon bushings, and transmissions:homer:

They never come out in the spot you need them to. With the collectors pointing down it requires a 90° bend right at the collector and it becomes a pain in the ass to package the rest of the exhaust around the engine, not sure on a caddy engine but sparkplug access and heat on the spark plug wires and boots sucks.<snip product>

Good points. In the case of the BB Cady, the center dumps actually land pretty nice except for the 90 bend.

Here is a good picture of spark plugs vs header as well as the fawked up header:

enginePass2_sml.jpg


The above picture shows why a rear dump header will more than likely not work :( If I have a rear dump, that leaves me no place to do a crossover.
 
Here is a picture down the passenger side:
exhaust1_sml.jpg
The red box is roughly where my upper link mount will end up. It will be upper side of the frame around where the body mount is(front/rear)

I'm curious how close I can get to the slave cylinder if I run the exhaust under it. Then if I can split the difference between the nylon RE joint and SM465 tranny.
 
If it was me I'd want at least a couple inches between a insulated exhaust pipe and and the slave cyl.
Exhaust wrap and a heat shield in that area and you should be good.

Another thing that could help get you some extra room is oval tube.
 
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