Exhaust Heat Wrap

[bpossel]

What is the current thinking on using heat wrap on the downpipes?

I will be receiving my new stainless exhaust system this week and am thinking about wrapping the downpipes before I install them.  On one hand I want to do this in order to keep the pass side cooler ...  on the other hand I dont like the look and its not original.

What are your thoughts on this?  Anyone else using heat wrap?  Pros, cons?

Thanks!
Bob  

[mdsalemi]

Is the stuff expensive?  Is it easily removable?  You can always try it and see if it has any effect.

[franjo_66]

Hi Bob

You may want to try ceramic coating as a better option than the heat wraps. Here in Australia I have used ceramic coating on the headers of various V8-engined cars that I've owned. It keeps the original look, its visually neat & appealing, and it does help keep things cooler.

BTW, your restoration & accompanying detail of records is phenomenal !!

Rgds
Frank

[bpossel]

Thanks Mike & Frank!

I decided to not wrap the pipes, rather install Dynapad on the floors.  This should keep the heat reduced in the cabin.
Bob  

[Mike Hughes]

Some of my vintage racing buddies tried heat wrap on their stainless headers and found that it severely SHORTENED the life of the headers!  Apparently it kept all the exhaust heat inside the headers and the stainless lost its rust resistance up near the exhaust ports.  The headers ate themselves up from the inside out within one season of racing - not a lot of miles!  When they started leaking, removing the heat wrap revealed sections of header turned into swiss cheese!  Replacement headers from the same manufacurer sources lasted several seasons (or until the first off-road excursion!) without heat wrap.

[Benz Dr.]

I've had heat wrap on my early header pipes for 10 years now and nothing leaks nor are there any problems. I got it from Summit racing.

It keeps thing a lot cooler in the engine bay. Works very well on 190SL's.

[Mike Hughes]

The swiss cheese erosion of the headers I was shown was all right up at the top of the headers near where they mated to the head - not a foot or more downstream.  I think perhaps one critical difference between stainless headers on a race car and a 230SL is that the headpipes are bolted to a cast iron manifold nearly a foot or more downstream of the head itself.  The cast manifolds probably absorb and radiate off enough of the heat that the header pipes are "relatively" cool compared to the temps upstream at the head.  Surely this may be one reason why M-B changed over from fabricated steel to cast iron exhaust manifolds during the 230SL production run. Our cars also seem to run a bit rich which generates a slightly cooler exhaust charge and we are running much lower average rpms (although it doesn't seem like it at times!) with much less wide open throttle than a competition engine.

So perhaps, on reflection, my knee-jerk reaction to heat wrapping headpipes on our cars may be unfounded.  However, I kind of like the look of my shiny new stainless Time-Valve headpipes!

[DavidBrough]

I first put heat wrap on my down pipes to try and reduce engine bay temperatures and it certainly helps quite a bit. I think it is more helpful for right hand drive cars as the pipes exit forwards, not rearwards as for left hand drive, so there is much more exhaust metal in the engine bay. At first I had a mild steel system and when I changed for stainless about a year later there were definite marks on the metal but no major corrosion and the pipes were quite old. When I changed to a stainless system I put the wrap on again and it does help with heat reduction. Not sure about the stainless system though as it is much noisier than the mild steel one but that’s another story


David Brough
1969 280SL Auto with A/C & 3.46 Axle