365 GT 2+2 burning carpet

My car had almost the same issue. We made sure the fire wall and the transmission tunnel had no holes and all the heat insulation was intact. It helped a lot, but in general the cockpit was still hot on certain days; but that hot to burn the carpeting. Good luck.

 

Car manufacturers seem to have begun to think about heat insulation for comfort only in the '70s, one of the reasons classics are often uncomfortably hot in summer and the reason why during restoration modern heat and sound insulation is installed in the interior. Judging from the pictures something I would recommend here.
Also, an under-car aluminium heat shield for the hottest exhaust parts is quite easily fabricated and highly recommended, a few of my cars have fabricated heat shielding added which looks basically stock and adds to comfort. Unfortunately that does mean a few non-stock holes are added to the car, but worth it. (and the manufacturer should have done it in the first place)

 

The heat shields are missing on most vintage exhaust systems I've inspected, including mine (250 GT/E). Also if the double or triple layer floor has started to rust inside, it is possible the heat insulation isn't working right. My floors looked very nice after blasting, but when we opened it up anyways, the inside was filled with chipping rust.

 

Running rich will cause that. A nice upgrade is to bet the headers a ceramic coating

 

the heat shields on the exhaust are to prevent boiling fuel in the carbs.
not to prevent interior heat,
had last year a lot vapor lock at 44 degrees calcius ( shadow)in France.
ciao
C.

 

There should be shields also on top of mufflers to prevent radiation heating up the floor panels. Late ignition timing will without a doubt make headers glow, but it should be pretty easy to note as the fuel consumption will also go through the roof!

 

Seeing as your floors are fiberglass in you car I think there is a much more pressing issue than the carpet getting bunt. There are heat shields riveted to the underside of the car above the mufflers that are intended to disperse some if the heat but obviously something is going on with the mixture for things to be getting so hot. We have put a product called Koolmat under the carpet and on the firewall of a few cars recently and the stuff works wonders for keeping the interior temps down.

Zac

 

Take your car to a competent Muffler shop and have them check for an exhaust leak of very hot gasses in the area. a Smog sniffer probe may help. My car ran extremely hot after my muffler rusted out. Cool after it was replaced.

 

With all due respect, I'd like to suggest more thorough investigation (and proper repair solution ?) for the actual cause/source of this excessive heat transfer before spending too much effort on possibly just "covering" it (no pun intended) with insulation materials. It could be, as suggested earlier, timing issue, faulty exhaust system components or...?
One good way is to check exhaust system temperatures using good quality laser thermometer at various points throughout the entire length on both sides of the system, even better if access to another similar system on a another car is available for comparison. Checking the temperatures without at least 30-60 minute serious drive might be useless.
Recording these measurements for reference is also advised.
Timo

 

My 365GT doesn't do this. I do have coated headers, but it didn't do it even before I had that done.

 

You could contact a company in Holland called HVL carinteriors.
website: HVL Class Leather® - Other products in stock
He should be able to help you solve this problem.
HVL Class Leather® - Contact