Heat Shielding footwells, transmission tunnels, etc?

[Steve-B]

During our recent (and gloroius) warm weather, the heat in the footwell and transmission tunnel has been almost unbearable. We've had the airflow knob pulled to direct outside air to the footwell but it seems to only move the hot air around. So that got me to thinking of solutions, and not finding a relevant topic here, I thought I'd ask if others have attacked this and if so, how? There's two sources of heat, and you can wrap the exhaust manifold and reduce a bit of heat from it, but what about the rest of the cockpit?

I looked at this supplier but it appears to be coming from the EU which means duties https://www.heatshieldings.com/en/hsarmor00-armor-self-adhesive.html

Thus curious if anyone with experience in this recommends a UK supplier of similar?

[stuart]

Try this stuff https://www.ebay.co.uk/itm/264478436338

Stuart.

[roy53]

Could look at Merlin motorsport catalogue page 63 Zircoflex products

Roy

[Steve-B]

Thanks @roy53 and @stuart I’ll give both a check. Lucky to have a chance to put my car on a hoist in a few weeks so it’d be the right time to do it…

[Malbaby]

If you have a front exhaust muffler, try fitting some insulation material onto the underside of the body near the muffler and also into the trans tunnel.

 

Edited September 18, 2023 by Malbaby

[A Brit in Bama]

When I replaced the rotten standard cardboard gearbox cover with an ABS version from Moss, I covered it with thermal insulation wrap left over from when we had our air-conditioning system replaced at home. 

It is essentially heavy-duty bubble wrap, with each face clad with reflective aluminium foil.   I just cut it to shape, and glued it to the tunnel with high-temp contact adhesive spray, and then I taped the joints with aluminium foil tape.  Works very well indeed, and once the underlay and carpet are in place, there is no trace of heat permeating the cabin.   I also covered the prop-shaft cover between the seats with the same stuff

I covered the tunnel in 2016, and it is holding up as good as new.

While mine was free, here in the USA, you can get the insulation very cheaply at any home superstore (B&Q equivalent) or online.

 

[Steve-B]

Guys who’ve done this: what size of material did you need to do the transmission tunnel and footwells to cut the requisite pieces? My rough guess is 2mx2m but I wanted to check before ordering 

 

TIA!

Edited September 19, 2023 by Steve-B

[Bfg]

Hi Steve,

Lierally speaking..  "Dam it !" to the engine heat (..and noise) coming through to the gearbox cover. 

Talking heat exchange / transfer.. the air forced through the radiator is heated and then flows around the engine. The hot engine and the exhaust manifold & downpipes heats it further still.  A good amount of this very hot air pushes through the bulhead's bridge to flow around the gearbox (heating that up) and under its cover.  By fitting a simple dam - the hot air, from the engine bay is instead mostly drawn out underneath the car ..where it is mostly carried away with the general air flow. 

Albeit a TR4A < here's what I did >   a little more < here > which then also shows the ribbed-rubber I used as an accoustic barrier inside the cover.  Household carpet under-felt is loosely fitted over the outside of the cover, if only to make it softer to rest my leg against as I drive the car.

There is no lagging on the exhaust manifold, downpipe or exhaust. The car is fitted with a nine-blade (mechanical) TR6 plastic type fan. Despite this being a steel gearbox cover (which conducts heat more easily than cardboard or fibreglass) the heat now conducted through it is quite acceptable. 

As an aside, my old Jaguar 3.8 straight-six exhaust manifold came within 1-1/2" of the corner of the footwell's bulkhead.  I used a square (man's-hankerchief size) of plumber's heat-shield fabric (formerly asbestos) locally on that corner of the bulkhead, and just that prevented most all of the directly radiated heat.  

Hope that helps,

Pete

[Z320]

Good morning Pete,

thank you for sharing this again,

you gave me the idea to make a steel cover like you did this winter.

I hope I will do the job at least half as good as you did.

Ciao, Marco

[Malbaby]

On 9/20/2023 at 6:53 AM, Bfg said:

Hi Steve,

Lierally speaking..  "Dam it !" to the engine heat (..and noise) coming through to the gearbox cover. 

Talking heat exchange / transfer.. the air forced through the radiator is heated and then flows around the engine. The hot engine and the exhaust manifold & downpipes heats it further still.  A good amount of this very hot air pushes through the bulhead's bridge to flow around the gearbox (heating that up) and under its cover.  By fitting a simple dam - the hot air, from the engine bay is instead mostly drawn out underneath the car ..where it is mostly carried away with the general air flow. 

Albeit a TR4A < here's what I did >   a little more < here > which then also shows the ribbed-rubber I used as an accoustic barrier inside the cover.  Household carpet under-felt is loosely fitted over the outside of the cover, if only to make it softer to rest my leg against as I drive the car.

There is no lagging on the exhaust manifold, downpipe or exhaust. The car is fitted with a nine-blade (mechanical) TR6 plastic type fan. Despite this being a steel gearbox cover (which conducts heat more easily than cardboard or fibreglass) the heat now conducted through it is quite acceptable. 

As an aside, my old Jaguar 3.8 straight-six exhaust manifold came within 1-1/2" of the corner of the footwell's bulkhead.  I used a square (man's-hankerchief size) of plumber's heat-shield fabric (formerly asbestos) locally on that corner of the bulkhead, and just that prevented most all of the directly radiated heat.  

Hope that helps,

Pete

That's a dam good idea.

 

[Steve-B]

Q: I'm still stuck on how much to order -- rough measurements = ~ 2M of the material.

If I go the Zircoflex route that's about £400, if I go the eBay route, it's about £50. I know the old adage of you get what you pay for, but as our cars are more weekend  runabouts I'm really struggling which to get.

[Bfg]

Steve, sorry but I cannot answer your question any better than yourself suitably armed with a tape measure, pen and paper.  In part this would be because, in your previous post, you've asked "what size of material did you need to do the transmission tunnel and footwells ?" ..and to my literal way of thinking ; 'footwells' are not clearly defined.

In my own TR., I shaped felt underlay to lay over the gearbox cover, the length of the driveshaft tunnel, the top face of the rear step (over the differential) and to lag the fuel tank. 

I didn't use underlay, nor any other type of insulation (..aside from the carpet set) on the footwell floor pans, nor under / around the seats, nor over the sills, or up the A-posts inside panels, nor up the slope of the footwell's bulkhead.  Nor did I insulate the forward / upright face of the rear step, up the sides behind the b-posts, or over the rear wheel arches. Similarly I did not attempt to insulate the underside of this car's bulkhead.

I do not mean to be rude nor obtuse in my reply, but simply suggest that one owner's expectation for noise &/or heat insulation, particularly within an open top sports car, is not necessarily the same as the next chap's, or yours.  And this would be reflected in the answer any person might give to your question.

Pete

 

Edited September 25, 2023 by Bfg

[Steve-B]

12 hours ago, Bfg said:

Steve, sorry but I cannot answer your question any better than yourself suitably armed with a tape measure, pen and paper.  In part this would be because, in your previous post, you've asked "what size of material did you need to do the transmission tunnel and footwells ?" ..and to my literal way of thinking ; 'footwells' are not clearly defined.

Pete

 

Thanks Pete and I share your thinking. Having had open top cars for more than 40 years, it is a subjective addition to do this but with all previous cars we've had, never had the footwell heat our TR 6 has so just trying to lessen it on an otherwise great car. The transmission tunnel is straightforward enough without a doubt. For footwells, my current thinking is the front firewall area immediately behind the engine on both sides should do the trick.

[Steve-B]

The engine/transmission was out last week for a clutch replacement (new plate, CRB,  slave cylinder, pins) so I finally had time to insulate. What a huge difference it makes - had to turn in the heater today to keep my wife’s feet, legs warm 

Heres  a couple pictures. Note different material as lining both sides of transmission tunnel consumed what I bought from eBay so blagged some from a friend. 

if you’ve not done it, absolutely recommend it and can’t wait for summer to come.

 

Edited April 21 by Steve-B