Heat wrapping manifolds. Bad idea?

[Russell Mc]

I'm going to be changing the manifold gaskets soon. Should I use this as a chance to heat wrap the manifolds? I've done stainless ones in the past but not mild steel. Is it a bad idea? Ceramic coating is a little expensive.

[gavgavgav]

I think they are a low grade stainless?

[Russell Mc]

If they are they certainly must be low grade

[Bluebottle]

Its cost me two sets of headers! I aint do'n it again.
Ceramicoat or that other one for me when i can afford it.

[Russell Mc]

Did it make them crack?

[rigga]

Heat wrapping can localise heat in places that then leads to cracking,i know the advantage of keeping heat in the pipes and the theory of that speeding up gas flow,but there seems to be cracking of manifolds even when not wrapped, so i thing doing so might well hasten problems


Saying that my scooby ones have been wrapped for nigh on 6 years now with no issues but they are steel.

[Bluebottle]

Both cracked at the four into one junction. I feared that the first set may have been the tight wrappings not allowing the headers to expand and contract freely ( u can't wrap each pipe separately towards the collector so u have to wrap all four to ensure a good heat seal otherwise you'll get a hot spot at the weakest point), but not certain and there was also signs of corrosion after 12 months.
The second set also cracked at the same place but there was extensive corrosion that rendered them unrepairable. They had only been wrapped for 6 months (in fairness the car hadnt turned a wheel in that time as the car was awaiting an engine rebuild under warranty.

[Russell Mc]

Ok dudes I've heard enough

[SILICONEKID340HP]

Don`t know what your setup is but the way to reduce under bonnet temperatures is to get rid of the pre cats and fit eather Clives Y piece or the ACT Y piece ..

I noticed the difference straight away..

Edited by SILICONEKID340HP on Wednesday 15th February 20:26

[Russell Mc]

Sorry should of said at the start the car is a precat

[black and green]

I've had to weld up cracks and splits in my pre-cat manifolds. They are stainless but a pretty crap grade and very thin walled. I wouldn't wrap them. Car Craft mag in the states had a few horror stories about headers failing within months after being wrapped.