Exhaust distance question

[randyscycle]

I should know this, but can't seem to recall, or remember:

What would be the safest distance for exhaust clearance to the fuel tank?

Obviously, as far as possible within reason, but on the 715 the tank sucks up a lot of room on the left side and I want to get by it, but still use what little space I have.

[Chumley]

I'm not really sure that there is one. I've seen tanks on stuff that had contours stamped or molded in so that the exhaust pipe could "pass through". On Jeep XJs the tail pipe is right on the tank, I think there's maybe two inches between them. What you don't want is the exhaust up neat the sending unit or any vents.

[fisherman]

My exhaust will be run above the frame from the bottom. I added 3/4" body lift when re doing my mounts to make sure I have plenty of room for between the cab and frame clearance issues. Both factory exhaust manifolds will run back behind the transfer then go into one muffler that will exhit in the stock location approximately. I am installing exhaust flanges where need to be remove section, or sections if I need to work on the truck. Everything exhaust will be inside the frame rails and tucked nice. It will not route near the gas tank. I should have plenty of room to add onboard air under the bed down the road. Not sure if this helps, but this is how I will be doing mine, in the next week or so.

[Barrman]

Randy,

Side exhaust outside the frame under the cab or duals on the passenger side inside the frame are about your only real options.

Cutting a hole in the trans crossmember and crossing over between the t-case and transmission seems to be the preferred method used by others.

[sermis]

My exhaust will be run above the frame from the bottom. I added 3/4" body lift when re doing my mounts to make sure I have plenty of room for between the cab and frame clearance issues.

The exhaust will get hot, really hot. My exhaust is between frame and floor. My wife had some shoes with plastic soles. The sole melted. Also causes lots of heat in the cab.

[MarknessMonster]

My wife had some shoes with plastic soles. The sole melted. Also causes lots of heat in the cab.

My old CJ experienced melted carpet under the seat from rerouting the stock exhaust too close to the cab underside. To this day, I can still smell the exhaust heat when running the truck for a while.

[brute4c]

The closer you are to the engine, the hotter it will be...I have a full size van that has the tank behind the axle...the exhaust is roughly 2 inches away on the drivers side...but wy back there it i much cooler than if it was in the area whre the stock M715 tank is...

I dont know the measurement to be safe in the M715's case but I would leave more than 2 inches...more like 3.5 to 4...maybe overkill but better than too close.

[randyscycle]

I plan to stay as far away as possible.

What I'd like to do, but may not be safely possible, is to take the left pipe and cross the frame in the space between the underbed tool box and gas tank, then merge with the right pipe in a single out the right side. Mainly to cut the noise down a bit. Having the pipes exit just past the cab makes for a lot of resonation in the cab. Not that this is a quiet truck, but it gets deafening at road speed.