I got some eBay heat insulation. Put some on engine bay firewall and passenger side near exhaust. Also put some inside under the passenger carpet and transmission tunnel. That, plus the electric fan, has made things much much better. The engine itself always runs at perfect temperature - it's been cabin heat that's been driving me mad. So it must just have been coming from the engine bay temperature - the electric fan must just be better at blowing out the heat. I also made a heat shield (insulation on back of it) to try to stop the direct heat from the exhaust getting to the fuse box and my relay box

 

The fan on the heater in my S Type is pitiful to say the least. It works on both settings, fast and slow but the amount of air pushed out hardly gets to the screen so demisting in the winter is an issue. Has anyone upgraded the fan in the heater and if so to what?
I had thought of buying an inline electric fan to sit in the ducting behind the dash out of sight but the smallest diameter I can find is 3 inch and I think from memory that the ducting is only about two inch. A small powerful 2 inch inline 12v fan would be ideal wired up to the same dash switch.

 

Orlando has the upgraded unit fitted to his car & seems satisfied. See his thread on the Register.

 

I fitted a Mondeo MK4 fan and a Jaguar X-Type heater core to my MK2 2.4, I also used a Corsa heater resistor to control the fan. I had to do a fair bit of metal work to the heater and i've not used it in anger yet but the amount of air it moves compared to the original is phenomenal.

 

Lyons at the NY Motor Show when a youngster complained that the heater in his Mk2 was not very effective ~ "You must wear a coat sonny".

 

Yes I have heard that quote before but it is not the heater as mine works fine eventually and the cabin is warm (not hot) but it is the fan that just does not produce enough power to get the air flowing. I don't want to cut up the heater but I am seriously looking at an in line fan if I can find a 2 inch version to add to the ducting behind the dash just to improve the demisting of the front screen.

 

I have a 66 and had a 67 as a parts car. The heater boxes and the fan and fan mounting were different between them, so I think you'll probably have to adapt something that works for your particular car. I expect anything reasonably modern will move a lot more air. My solution was to park the car for the winter!

I have tested a number of different blower and housing combinations for a different project and I can say that there is virtually no correlation between the squirrelcage size, motor rpm and the amount of air moved. The housing the squirrelcage fits into is also a vital part of the equation. Most that I tested were in the 3-400 CFM range. An outlier was the rear AC blower from a 2005-2007 Ford Freestyle - it moved over 600 CFM, yet was no bigger than others I tested.

 

The convoluted tubing used to the various vents even makes a difference. The smoother the inside the better. You don't want turbulent air in those tubes.