MG MGB and MGB GT Tech Talk
I look forward to doing some work on my heating system. Any thoughts on insulating the demister tubes while the heater box is removed? How about expanding foam or something to keep the demister airflow nice and hot on its way to the windshield?
I don't think you lose much heat in the 10 inches of demister pipe.
Len, the only thing I can think of that might help, and that would be so marginal that I doubt if you could even measure it, would be to change the type hose to something with less heat conductivity. There really isn't too much room up under the dash for any insulation around the hoses. I think the best upgrade you can make to the MG heater unit is the addition of a GM 3 speed blower motor with larger squirrel cage blower. This really fills the housing so there is very little 'blow by' within the housing and the higher motor speed really puts out a high volume of air. Check the archives, the installation was covered in detail and the link to the website was posted on the board. I did the same in my Midget and used the GM switch to control the fan. I think it works as well on low as the stock MG unit did.
Probably this one.
http://www.mgexperience.net/phorum/read.php?1,519704,519704#msg-519704
Thanks Bill & Derek. I like the blower upgrade and I'm gonna use it regardless of what other mods I do. I think I have that blower (with resistor coils) on my '82 work truck!