Insulating the exhaust manifolds

[ajg]

There appears to be many problems caused by the high under bonnet temperatures on the Chimaera, I have had lots of rubber components fail due to this I suspect.
I have seen an insulating bandage for sale which is designed to be wrapped around exhaust system components.
If this was wrapped around the manifold pipes this would reduce the temperature under the bonnet and hopefully extend the life of many components.
Can anyone think of any side effects?
Would the 'cat' get too hot perhaps?

Andy G

[hut49]

This has been covered pretty thoroughly in previous threads eg www.pistonheads.com/gassing/topic.asp?t=17373&f=8&h=0&hw=wrap

[ajg]

hut49 said:

This has been covered pretty thoroughly in previous threads eg www.pistonheads.com/gassing/topic.asp?t=17373&f=8&h=0&hw=wrap

Thanks
All the posts appear quite positive, has anyone done this and had problems afterwards?

Andy G

[GreenV8S]

Yes, I had mine lagged and barely a hundred thousand miles later the headers were so badly corroded they had to be replaced.

[M@H]

The problem is if you don't use the car all the time, the stuff can be a bit of a sponge to moisture so if it gets wet it just holds the moisture against the metalwork.. If you used the car every day then its probably not so much of a problem. (IIRC IMO etc)

Cheers
Matt.

[Incorrigible]

Did you mean 100,000 miles ??

If so the only reason not to do it would appear to be laziness. Unfortunately I have that in abundance

[Dodgy Dave]

I've had problems before with heat wrap, not on a tvr but what happened was the exhaust was getting so hot that any excess fuel was igniting in the downpipes which led to the destruction of the welds where the pipes joined into one.
It wasnt a cheap set of pipes either!!

[Hamish400]

I wrapped stainless steel manifolds on a Relaint Scimitar abt 3 years / 12000 miles ago. After wrapping they were sprayed with relevant paint to reduce dirt impregnation, water soaking etc.

They still look nice and have given no problems apart from a small fracture (5mm long) at the weld to the manifold flange on one branch. This was about 1 inch before the wrap started and I suspect due more to weld undercut, or vibration, than any effect of wrapping the pipes.

They still look nice.

I am planning to partially wrap the exhausts on my 400SE where the exhaust is in close proximity to the new chassis or the body.

Rgds
Hamish

[AndrewC]

Do what I do - keep the fans running all the time and don't wait for the temrature build up. Since I've been doing that the car runs better, pinks less and the temp gague stays at the midway point.

Makes more sense, the original set up in other Rover engined cars had cold air being sucked in constantly plus an electrical back up!

Wrapping the manifolds only causes the heat to escape elsewhere which menas under the car!!

[D.K.Dalton]

Exhaust Wrap is realy intended for competition cars and does have the disadvantage that the heat in the system is transferred further down the exhaust with, on occasion some dodgy results. I had the manifold on my 1600M ceramic coated by Camcoat
(www.camcoat.u-net.com) The result is absolutey superb and even the cold water which drips on it from the bonnet vent has not marked it. (This used to remove Sperex in minutes.) Cost wasnt daft either.

[david beer]

i think the fans on when slowing is the easiest and cheapest way to control the heat.I know nothing of the heat wrap stuff so i can not comment. Strap an adjustable thermostat/sensor to the outlet of the rad or just "dangle" it under the bonnet. In cold conditions it would be probably not be activated. Half speed fans would be quieter and enough to keep the air moving. The original otter would act as normal.

[drum4it2]

AndrewC said:

Do what I do - keep the fans running all the time and don't wait for the temrature build up. Since I've been doing that the car runs better, pinks less and the temp gague stays at the midway point. Makes more sense, the original set up in other Rover engined cars had cold air being sucked in constantly plus an electrical back up! Wrapping the manifolds only causes the heat to escape elsewhere which menas under the car!!

Hi all, sorry changing the main subject slightly... my Chim 4.0 has the fans wired to be on constantly - no switch - I was worried about this, Andrew, you seem to think it's a good thing though? Would it be best to fit a switch and is it possible to have a variable speed switch fitted? Any comments anybody? ta muchly!

[shpub]

Fans permentently switched on either means:

1. The otter switch is faulty.
2. The overide switch is on.
3. Someone is trying to hide a car that has a serious overheating fault.

Steve
www.tvrbooks.co.uk

[jellison]

Modwise Fan controller - SORTED