Technical Distance - ??Exhaust Pipe from Fuel Tank

When routing an exhaust pipe; up over rear and near the gas tank , exiting out under bumper -what is considered safe/unsafe distance away from gas tank ?

I was told at that point the heat of the pipe is not as intense as further up at engine and mid area of the system

* Found some example pictures

 

Four inches.

 

my 34 ford, and i think fords thru about 1940 the exhaust is only about one inch from the tank. however, flathead exhaust is cooled going thru the water jackets, and lets not forget flatheads have been known to have vapor-lock issues.

 

IMO just enough so as not to touch.
There is not enough heat to talk about.

 

I’ve got a pickup that exhaust pipe is a little over 1” from the spare tire with no shield and never had a problem. You can almost grab the chrome tip.

 

I would give myself all I could,,,as a safety margin .
When sitting idling in traffic in July,,,,all things get hotter quick .
Just saying .

Tommy

 

Factory on my '50 Buick is a couple inched.

Ben

 

When close by, a SS heat shield might serve. Or an extruded AL jacket around the pipe. Convective air flow would lower the pipe temp.

 

If in doubt, wrap the pipe.