Heat; Where's it coming from?

[Grumps]

Well, I took the wife riding in 30 Coupe yesterday and the cab really got hot and a little uncomfortable. A lot of heat seems to be coming from the firewall and floorboard areas even though I have everything double insulated on the inside of the firewall, kick panels, and doors. I didn't put additional insulation on the wood flooring because I figured in didn't need it because I have carpet. The motor isn't running hot, so I don't think that is the issue. Is there anything else that I need to do because I really enjoy taking my wife riding in the Model A but don't know if she will be willing to go with me because of the heat especially during the summer months here in Texas.

[eagle]

Have your wife "shoot" the floor, firewall etc with an infrared thermometer while you're driving. Make sure you have an exhaust shield in place under the floorboards.

[Grumps]

Where do I get an exhaust shield? Is it something I make or can it be bought?

[nkaminar]

Modern cars all have them. It is a piece of sheet metal that reflects the IR heat from the exhaust pipe and muffler. You can make one yourself if you are handy with forming sheet metal. It does not have to be very thick. Or you can buy it from the parts vendors.

See https://www.snydersantiqueauto.com/p...8527&cat=41736

[eagle]

Here's one: https://www.mikes-afordable.com/product/A5230HS.html
Mine also has a shield screwed to the floor boards, It looks factory, I guess I don't know if it is or not.

[rotorwrench]

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Model A cars were sealed fairly well at manufacture but can leak more as the floor seals deteriorate. The wood floor is a fair insulator but not perfect. The lower firewall wasn't insulated yet in Ford cars. With the engine pans in place, most of the heat exchanged from the radiator will flow out the louvers in the hood sides but not all. The exhaust system contributes a lot of heat as well. The right engine pan augments the air flow around the exhaust a little bit but not all that well either. Ford did do a fair job of closing off the cab from the engine compartment air flow but those improvements got better after the model A era as the bodies were set up for better flow and improved insulation.

If the air in the engine compartment is flowing well and the floorboards are sealed as Ford did them then and added lower firewall insulator might work if well fabricated. Wrapping the exhaust pipe with fiber insulation tape may also help a good bit. Ford just made the windshield to be opened a bit to flow more outside vent air in and out through either the side windows or a rear window that can be opened if so equipped. This vents the cab but it doesn't solve the problem.

This is a link to fiber heat insulation tape.
https://www.abthermal.com/basalt-fib...tion-tape.html

[Bob Bidonde]

When restoring my 190A Victoria, I took these precautions plus I installed a heat shield over the muffler.

[BRENT in 10-uh-C]

I am curious of a couple of things. To begin with, what is the temperature difference between the outside of the cabin and the interior of the cabin. For example, if you are driving in 90° weather with 90% humidity and the inside of the cabin is uncomfortable because it is 80° inside, not sure there is much you can do short of adding a method of cooling the air.

Next, these are some things that were originally designed to keep the hottest of air away from inside of the cabin, so check these first. Are the floorboards the proper thickness as original? Is the floorboard seals installed on the perimeter and are the floorboards properly screwed down?? Also, are the engine splash pans installed correctly???

[Phil Brown]

Does the car have a heater manifold where the door in the firewall might not be sealing well ?

[Y-Blockhead]

Heat can sneak in around the floor by the cowl front mount and behind the kick panels. Especially on the Navigator's side where the exhaust manifold is.

[Flathead]

Y-Blockhead, that is a very good observation!

[aermotor]

How does the car run? I had a later model non-Ford that was running like c**p did everything I knew and no change. Finally noticed the engine compartment was extremely hot - dual exhaust. One side was blocked. I know this is a little beyond a Model A but I was also coding random miss fire on the same side cylinders. Don't know if Model A 's have had muffler problems that would cause this or not, might be worth a check for air flow out the tail pipe.

[Grumps]

Thanks for all the advice and this is some answers to your questions. I don't have the engine splash pans installed at this time, but I intend to as soon as I can get them cleaned and painted and the floorboards are the correct thickness and have the seals around them and are screwed down. The engine is not running hot or at least I don't think it is but I don't have a temp gage but intend to buy a temp gun from Harbor Freight soon so that I will know. I have insulated the entire inside of the cab and I will remove the floorboard and install a metal heat shield on the passenger side to help with the heat from the exhaust. I have wrapped the exhaust pipe that is closest to the floorboard with Header wrap to see if that helps and I am going to put a muffler shield on it like Snyders sells. If there is anything else that I need to do please let me know

[nkaminar]

Move to a colder climate.

[Marshall V. Daut]

Grumps -
Just a quick heads-up on painting those engine splash pans: do not use straight enamel spray paint, such as Rustoleum, at least not on the passenger's side pan. Dripping fuel from the carburetor (all Model A carbs leak some fuel, especially when over-choked) will cause the enamel paint to crinkle, lift and then peel off. Because there is no fuel leakage on the driver's side to worry about, you could get away with straight enamel there.
Either use lacquer or catalyzed acrylic enamel if you are spraying the splash pans, or better yet, have the pans powder coated. I have scraped crinkled enamel from dozens of splash pans over the years and it is no fun getting the pans down to bare metal in order to prepare them for a longer-lasting finish. I assume you only want to do this once?
Marshall

[BillCNC]

Could the hot air be coming through the shifter hole in the floorboard, throttle linkage hole being to large, or through the terminal box?

I live in the SoCal desert where it's easily 105+ daily in the summer and the heat shield has never crossed my mind. I was getting heat coming up through the shifter hole but a shifter boot and e-brake rubber boots solved that. I do agree with eagle in that you could use an IR temp gun to search for the heat source.

To fight with the cold, I installed some of the cheap reflective bubble foil insulation you find at Home Depot which was a fraction of the cost of the stuff the vendors sell. It worked perfectly and made it much more warmer in the winter and deadening sound, but no real benefit of cooling in the summer. Opening the windshield and all the windows does fine with that. Wind wings keep the tornado inside the car at bay.

Regards
Bill

[katy]

Open the windows and open the windshield a bit.

[Ed in Maine]

I think you would get better heat insulation if you mounted the heat insulator sheet metal on stand-offs so that there was a flow of air between the heat shield and the floor board. I used 1/2 in. long cylinders. There is a greater amount of heat transfer with direct contact (wrapping insulation) as opposed to providing an air gap between the shield and floor boards. Ed

[5lugnuts]

I suspect ED in Maine above has the right idea. I read on this board a few years ago that the most efficient amount of stand off would be one inch of air flow between a heat shield and the item to be cooled (floor board). I think the man who wrote that was required to do an analysis for something on his job that involved layers of moving air for the most efficient cooling and one inch was his conclusion. I never read if he tried it on his car. It makes a lot of sense though. I plan to try it "someday".

[Herb Concord Ca]

If your A is still too hot in the summer, it's time to install an A/C in your A, you won't regret it! Mine has been in my Slant T/S for over 10 years, we love ours. I live in the bay area.