excessive heat under vehicle

[dodgey68]

ok I now this might be a silly question,, and these cars are old dinosaurs, but as far as that goes, but my question is  the amount of heat under these cars,,, I felt the seat belt bolts while on a drive ,  ,, holly shit ,there really bloody hot,the kids know not to rest there feet any were near them , is there fins or scoops? to direct air to maybe cool down or drag heat away,, I had an issue with vapour lock (heated fuel lines) ,, I fixed that ,,
just throwing it out there

[JR]

I'm sure you know this, but any additional airflow you direct under the vehicle will likely lead to lift at high speeds.

I would start with heavy duty fluid coolers to protect the components and lower temps from within. Trans cooler, rear diff cooler, oil cooler, brake cooling ducts, etc.

You track your 68, right? Is the heat noticable on high speed tracks, or more so on short (one mile) circuits?

I've never tracked my Charger, but I have spent a good bit of time tracking an E36 M3 here in the southeast, and Ive noticed that on long, high speed courses like Road Atlanta, the average speeds are high enough that the brakes hold out longer and the driveline temps take MUCH longer to build up.

When I run it on a short track, like Talledega Motorsports Park, (which is really a go-kart/motorcycle track they've recently opened up to car HPDEs) I can only really push it hard for 8 minutes or so before engine temps climb drastically, and the brakes start fading. (Very annoying in a 15 min heat.)

Out of curiosity, have you tried running without your front chin spoiler? Maybe on the short tracks where the speeds are lower and there's less noticeable lift you could try removing it and test what difference it makes.

[XH29N0G]

I haven't checked my car, but remember another 1970's car (a pinto) as a kid has such hot floors that we would complain to my parents about our feet on long summer trips.

Do you have insulation under the carpets?  It also might be as simple as some sort of heat barrier on the underside.

[NHCharger]

Didn't you replace the tired 318 with a built 440?? More horsepower=more heat. I installed some under carpet insulation on my 68. On my 71 I took temperature readings of the floors before and after I installed the insulation. Dropped the temp about 30 degrees

[cbrestorations]

Get the exhaust ceramic coated, will take most heat away. Most modern cars have factory stainless exhaust which doesn't disapate heat like mild steel exhaust. I had the headers and full exhaust coated on my race car, as last time I raced it without my braking shoe  melted to the brake pedal from radiant heat. After getting exhaust coated it then melted and burned the fiberglass quarter panel and plastic skirting on the rocker. No heat in the car or under hood, all went out the exhaust