Thread: Gearbox Cooling - Defender

Originally Posted by rick130

Hi Ross.

The best type is a silica based thread, I used ThermoTec brand. I wouldn't use a glass type, the temp rating isn't high enough and it'll die a premature death.

There are several sizes, depending on the OD of the pipe.
I had a few rolls on the shelf left over from years ago (1.5" IIRC) for header pipes on the race car so used that on the 3" exhaust, but for a normal exhaust the wider type is preferred/easier to use.

I started at the engine/dump pipe end and use a large stainless worm drive clamp to hold it in place, (the wrap makers also have fancy, low profile stainless fasteners like a zip tie that you can get too) then wrap like wrapping bike handle bars and finished off the same.
I also sealed mine with a silicon based (high temp) paint, although from memory Inc didn't bother when we last spoke about it on here.
The stuff I used was natural off white/sort of golden, but you can get in black these days too.

I went all the way to the t/case on mine and it makes a huge difference in the temp coming through the tunnel.

am seriously looking at this option


has anyone been down this path ,,,,and had any issues long term

with water crossings and the associated temperature differentials,,,and thermal dynamic reactions ..within the relative sections of exhaust???

Originally Posted by trailcutter

am seriously looking at this option


has anyone been down this path ,,,,and had any issues long term

with water crossings and the associated temperature differentials,,,and thermal dynamic reactions ..within the relative sections of exhaust???

Read my post above

Over 100,000km and lots of water crossings, sometimes multiple crossings in a day during the working week.

Originally Posted by scott oz

[snip]

Curious why not use the insulation tape on SS exhaust

Originally Posted by 130man

[snip]
I am also interested in why this product or technique shouldn't be used on Stainless pipe.Cheers, Ross.

Thermal fatigue cracking of the stainless.

I used to (wrongly) assume this would happen to mild steel too but Inc assured me otherwise, after having experience with it on big marine turbo diesels.

Originally Posted by rick130

Read my post above

Over 100,000km and lots of water crossings, sometimes multiple crossings in a day during the working week.

cheers rick i thiught everyone had died.or fallen to sleep..

Originally Posted by rick130

Thermal fatigue cracking of the stainless.

I used to (wrongly) assume this would happen to mild steel too but Inc assured me otherwise, after having experience with it on big marine turbo diesels.

While I'll check mine I thought that standard LR exhaust (TD5 110) were SS?

Hi all, ordered up the thermotec tape yesterday.Should be in by Friday but I will pick it up next week.$99 for a 50 foot by 2 inch roll.[American product]. I saw, in the uses for this product, that people wrap headers and turbos too.Would this be beneficial or would it cause trouble if I wrapped the manifold? Could it over heat the Turbo? Could it cause warping of the manifold? I just had the manifold studs replaced and a second hand manifold installed because the original was too bent to machine!! My exhaust seems to be mild steel, not SS.Cheers, Ross.

G'day 130man,

I am very interested in what you find after wrapping the exhaust wrt heat in the cabin. I think that I will probably go down this route.

cheers

Boots

Originally Posted by one_iota

I've been thinking likewise Matt.......run a metre or so of 75 mm flexible rubber duct with the front of the duct above the crossmember under the transmission against the chassis rail on the passenger side then running back and into the void between the seat boxes. The idea being that the duct would pick up enough clean air to blow into the void and remove the air pocket (if that is what is causing the problem).

I have some 90 upvc pipe and fittings but was a little concerned that if it came off at speed it might do some damage either to the Defender or those following.

If that works then a mandrel bent metal tube might provide a more robust and permanent solution.

Seeing that you are just down the road we should put our heads together on this one.

HI,

I have tried this option and the results were not fantastic because when you duct air from the front of the car you create a high pressure zone in the void between the seat box.
Having the interior of the 110 acting as a depression zone because of the pressure vents or open windows (all cars have pressure vents fitted somewhere on the body, the most obvious are the 1989 110 model. Pic attached)

This will result in having the hot air flowing more rapidly from underneath the cabin to the inside of it.

For this year I will try to fabricate a fiberglass bonnet fitted with louvers that I hope will create a depression zone on top of the bonnet to suck out the heat from the engine bay, preventing it or reducing it from being stuck between the seat boxes.