In what passes for winter here in SoCal, I have been driving my 1923 Runabout around night & day. Only once has it been cool enough for me to wear a jacket, and only a couple of times a light sweater. Sure, winter was brief this year, only about two weeks, but even so, this IS February and it doesn't seem reasonable to be as warm as I am in an open car.
Recently the daytime temps have been in the high 80s and even into the low 90s. When I get back from a drive, often I have damp clothes from sweating and this is winter!
This seems like an awful lot of heat for a 20 hp Ford to produce and the motor is not running hot. It doesn't smell or act hot and when the Motometer is fitted the temps run right where they should be.
Where is all this heat coming from? Is it leaking through holes in the firewall & floorboards or radiated from the floorboards or some combination of both? What can be done about it?
I thought of tacking some AL foil to the bottom of the floorboards but that may not stay as the floor rides directly on the transmission inspection cover. It would tear up or wear through any applied foil.
What have you done that worked? Summer is coming and the heat will only get worse . . .
I wrap my exhaust pipe in racing pipe tape and I also use that stuff that dirt track drivers use to insulate the floor under the boards. Then I go one step further, I use those mats that woman use for their exercise cut to shape under the Ford floor mat. I used to have problems with my feet getting hot when driving long distances. Not anymore!
The late, great Harold Sharon taught me this trick. Get some sheet metal, preferably shiny. (I cut up a NAPA drip pan.) Screw it to the bottom of your floor boards, right over the exhaust stack, which is where your unwanted heat is coming from. But use a couple of washers with each screw as spacers, to keep the metal away from the floorboard and let some air circulate between the metal and the wood. Works great. Cheap, too!
Paul when I've been driving normally my exhaust pipe is hot enough to burn the stew out of you if you manage to touch it - like instant blister hot. I discovered this the hard way when going to tighten my clutch band right after driving. So I got some header wrap from Advance Auto and it does such a good job that I can grab the pipe with my hand. I wouldn't want to hold on really long, but the difference is incredible. It drastically lowers the outside temperature. My floorboards aren't nearly as hot as a result. I would wrap your exhaust pipe starting right behind the big exhaust nut all the way down as far as the roll you get will do.
There are a couple of good ideas. On the header wrap, how is it attached? Possibly with a hose clamp?
Does sealing the gaps in the pedals & levers help? Is there an easy way to do this?
Yes, hose clamps. The wrap kits usually come with clamps.
The vendors make boots that help seal the gaps around the pedals and brake lever, and I have to believe they help, but they take a little extra fussing when it's time to take the floorboards out.
the tin shield that goes under the pedals to deflect the hot air from coming thru around the pedals really makes a big difference imho.
I have one of these tin shields but could not figure out how it is supposed to fit. Do you have a pic or drawing of how it is supposed to install?
I have found out it is cooler with the top up for shade and I also tilt the bottom of the top windshield in to direct air to the floor and legs. Works pretty good for me. My wife and I almost cooked on a 50 mile tour on a 82 deg day because we thought we would get better air flow with the top down--wrong!! Sun was cooking us from above and the floor was cooking from the bottom. Don.
I also use the racer's exhaust insulation. I got mine from Autozone.
All you need is one clamp. Start at the nut and wrap it so the tape holds that end. Use the clamp to stop it from unwinding.
Depending on how much you want to 'hide' or are willing to cover up, there is a self-adhesive cut-to-fit product called Dyna-Mat, (or similarly made) which is widely used in the performance industry. The exhaust wrap has also been a long-time racing use. Have not encountered the heat shield, but it make sense.
Paul, this is how the pedal shield is mounted on the bottom of my floorboards. It rubs on the hogshead just a little, but not enough for me to move it.
I also find the need to choose somewhat between airflow and shade from that radiant heater in the sky.
Best regards. BE
We have no side curtains, so we find that we drive with the top down in the Winter and up in the Summer. In the Winter, the top down allows heat from the sun. In the Summer we like the shade. We have driven with the front door open to help get some of the heat out in the worst of Summer. I supposed if one were to have side curtains, then top up and curtains on might be warmer, but our Winters are mild by comparison to the North and the windshield blocks most of the wind. At 35mph, Winter driving with the top down on a sunny day is pretty comfortable.
I drove the car on a tour Saturday in 90° weather and thought I might try to feel where the heat was coming from. It was certainly hot over the exhaust pipe area of the floorboards but there was plenty of heat coming from the area of the pedals and lever as well.
Lagging the pipe and the pedal air deflector will be good places to start. Plugging some of the holes in the firewall with rubber plugs might help some too. Sealing the lever looks like it might be tougher. I wonder if some sort of fiber whisker seal might work? These could also help with the pedals . . .
I started the tour with the top down but put it up at the first stop as the sun was so fierce. My top is a ratty old one that has had the rear portions removed so that it functions more as a sun shade than a real convertible roof.
I sealed my brake lever with a 1/16 inch thick black rubber sheet, cut to the shape of the floorboard bezel and sliced down the middle. I flipped the bezel over and sandwiched the rubber sheet between the bezel and the floorboard. I suppose you could do the same for the pedals, with three slits instead of just one.
Great idea Mark. Was the rubber you used like a weather seal in that it was very flexible? How durable is it? How well did it work? Is it cooler in the cockpit?
Very flexible, I found it on T-bay:
I was trying to achieve the opposite of you, trying to keep the cold air from blasting in through the brake lever slot. I've only had it on there for a week or so, but it does a good job of stopping the cold draft. I kept the pedal slots open because a little bit of warm air comes in through them, but I may seal them up in the summertime.
(Message edited by cudaman on February 16, 2015)