I solved the heat problem through the tunnel the following way. My metal
tunnel is lined on the underside (transmission side) with the aluminum
bubble insulation you can buy at Lowes. I installed it 4 years ago with a
good spray adhesive and then sprayed it black. You can not even detect it
unless you look very close. It's a tight fit with the tranny but very
doable. If you are concerned or have the rubber plugs for the dipstick with
the transmission tunnel, adjust accordingly. I welded my tunnel access shut.
That coupled with the under liner for the wool carpeting eliminated ALL the
heat from that area.
----- Original Message -----
From: "Carl TR" <firstname.lastname@example.org>
To: "'Cosmo Kramer'" <email@example.com>; <Triumphs@autox.team.net>
Sent: Thursday, June 30, 2011 10:25 AM
Subject: Re: [TR] interior insulation - TR3
> Welcome back!
> First - the insulation is for inside the cockpit; not in the engine
> compartment. I live in Florida and if I can't get the ambient temp of
> cockpit within reason - my wife will never ride in the TR.... and it will
> be less enjoyable for me.
> Radiator shrouds (you don't mention which car) are designed to force air
> through the radiator - cooling the water - cooling the internal engine.
> fan is designed to aid in pulling that air through the radiator (when the
> car is in motion). If the ambient air temperature is 90^ or better - it
> less effect on cooling the water. The electric fans help by generating
> flow when the car is not in motion.
> There are only two places for the air to escape the engine compartment (on
> TR3 but similar for other cars) -through the vent slots at the top rear
> of the bonnet/hood or under the car (through the transmission tunnel).
> Since the top escape is limited - most of the heat is directed down and
> - against the firewall and through the tunnel. That creates the large
> amount of heat in the cockpit area. It is aggravated by the placement of
> the exhaust system(first muffler) under the passenger side. Hence the
> to insulate the cockpit. R15(x2) on the firewall; floor; tranny tunnel;
> elsewhere. Also it will provide some relief from road noise (when the
> curtains/hood are installed)
> It is my understanding that some racers install a deflector at the bottom
> the radiator which helps create a negative pressure behind the radiator
> below the front of the engine. This helps pull the hot air (after the
> radiator) down and below the car rather than into the firewall and then
> into the tunnel. I have installed a 1 1/2" deflector in the front cross
> member below the radiator (it also protects the alloy sump). We'll see if
> it helps.
> As to vapor lock... Do you have a heat shield between the manifold and
> carbs? Again - the hot air generated by the manifold has to go
> the shield deflects it to the rear of the carbs so that it can then flow
> (or down) and out of the engine compartment.