My little 1923 Runabout has been running well enough to drive for 6 months or so now and each drive has been a process of practicing my T driving skills and sorting the car out. All sorts of things have needed adjustment or work of various kinds. One of those issues has been the high heat level in the cockpit.
Driving the car even in what passes for winter in SoCal has been a sweaty experience. There are all sorts of things that need to be done but I thought I would start by lagging the exhaust pipe with the exhaust system wrap sold to hot rodders.
The wrap is Cool It by Thermo Tec and I found it in black at the local Auto Zone. There are no fasteners with the wrap so I used hose clamps that were already in stock. The ones in the picture below turned out to be way too large and smaller clamps were used. I have checked the tightness several times and the clamps are holding well and do not seem to mind the heat. They are working well.
After several weeks of driving the car I can report that the wrap has made a huge difference. It still gets warm in the cockpit but it is much better than it was. The floorboards also feel markedly cooler than the were. I consider this wrapping a success.
I have read about rust issues under the wrap. In this case, I had already fitted a stainless pipe for clearance to the fuel line issues so it seems unlikely that rust/corrosion will be an issue here.
Next will be insulation of the floorboards. Here is a sample of a little bit that Larry Blair installed when he fitted the Ruckstell axle.
I did the same thing to my 19, except I started the wrap at the pack nut. I overlapped it when I started so I only used one clamp.
It starts off black but turns grey once it get hot.
I did it to help stop vapor lock on hot days. I also moved the gas line so it passes over the exhaust pipe at a right angle further back and then along the top of the frame near the outside.
We just got another 50 ft from O'Rielly's
You did TWO layers? I'll bet that your pipe stayed cool! How is the cockpit heat now?
The only real problem with wrapping is it will burn the packing out of your muffler. Much better to just build a stainless steel heat shield for the header pipe and maybe cheaper.
Here an example on a Bigger T.
Charles, I don't think model T's have any packing in their mufflers.
That should say baffle inside and what ever the packing on the outside of the muffler is I believe.
Wrapping super heats the pipe and the exhaust gasses just keep getting hotter the longer the engine runs.
You can google exhaust wrapping and find out the pro's and con's.
Charley - do you think that the gases in the pipe are hotter than without wrap and therefore erode the steel baffles more quickly? That is not a problem I had even considered.
I did wonder if the heat not radiated by the pipe might be passed out the exhaust pipe cooking the spare tire more than it had otherwise. An exhaust deflector might help with this. Has anyone checked the exhaust temp outside of the muffler before & after wrapping the pipe?
I made a heat shield for the floorboards on my T speedster because they're so much lower and closer to the exhaust pipe.
I just cut some plain 22 gauge steel sheet about 6" wide and then sectioned to match each floorboard piece. 1 washer between the steel and the floorboard leaves me plenty of room and also works awesome.
I was actually burning one section of floor because it was getting so hot it'd start smoking. Lol smoke in the car while you're driving along is VERY disconcerting.
I replaced that board and added the shield and now it barely gets warm to the touch. I just have the leading edge of each piece of shield lightly flared to catch a bit of air.
Paul We had one layer - actually two because we spiral wrapped the pipe with an overlap.
It helped with the heat and there was no problem with the muffler.
Dexter is right - there is no packing in the muffler.
The last time I remember any muffler having packing was the glass packs from the 60's and we wanted to blow the packing out to get the "mellow" sound.
I highly doubt that the hotter gasses will damage the muffler.
After we change the motor in out T we will most likely do a double wrap - 4 layers - from the motor to beyond the gas tank to lower the heat some more.
I just tilt the top windshield IN to direct fresh air down to my feet, works great, Don.
I went over the firewall this past Sunday and installed rubber plugs wherever there was a plug in my kit that would fit a hole. Next some sort of plug will need to be ginned up for the large vertical holes that admit so much hot air into the cockpit.
I noticed on the insulation that Larry installed that it did a fair job of closing the hole for the Ruckstell shift lever. If that same sort of insulation were to cover the entire three piece floorboard set with just slits for the pedals & lever I imagine another huge source of heat will be reduced. The boards are far from a perfect seal with the body & firewall and those gaps too might be addressed by generous cutting of the insulation.
None of these steps will be 100% effective but taken all together I'm thinking that the car might be very pleasant to drive even in the summer heat.
I have 4 cars that have the wrapping, some were wrapped as far back as '98 and all mufflers have survived. Griping from the wife about hot floorboards has drastically decreased , too. Floorboards are also lined with aluminum foil race-car insulation on the underside, also.