I have bought some Cool It Thermo Tec Copper Impregnated Exhaust Insulating Wrap. I wanted it to try and stop the heat affecting the paint on the engine lid, as there is a tendency for the paint to craze around the air vent due to the heat. I am going to wrap it on the exhaust down pipes, it is meant to reduced engine bay heat by up to 70%. I doubt it will do that on a 500 with the exhaust box being just next to the engine but I am sure it will make a difference. Also as anyone who has worked on a 500 knows you always burn your hand when playing around with the distributor, so it should prevent that. Also it doesn't look as bad as some other tapes you can get for wrapping manifolds. PS The cable ties are only on there for measuring up purposes it will be held with some jubilee clips. The 500 parts site in Germany sell it but they wanted Euro 99,50 for it. I managed to source it in the UK for £25.

Anyone have any experience with it or similar products?

Get these guys to do the whole thing, some lovely Colours and old school finishes
http://www.zircotec.com/page/--performance-colours/47

I wrapped mine in a similar material and the engine bay still gets hot, though I don't know whether it is cooler or not with the wrapping. You certainly cannot touch the wrapping after the engine reaches operating temperature.

Out of interest, my other car (an old Alfa), has had the exhaust manifolds ceramic coated and that actually does seem to make a difference, though once again, I'm unsure of the degree of cooling.

Chris

I'm with Chris on this one. I've wrapped mine and although it looks good it certainly doesn't cool the engine down as much as it claims. It's better than a bare exhaust but you cant go anywhere near it once its up to temperature and that includes adjusting the distributor

30% surface heat reduction with ceramic coating apparently . . .

I would be a little bit wary. This works well on stainless exhausts, but on mild steel it traps moisture causing the exhaust to rust more quickly. Exhaust heats the air trapped between it and the wrap, as exhaust cools vapour turns back to water and cannot escape.

Would VHT paint not be a better solution (or heat shields/reflectors??)

Konrod said:

I would be a little bit wary. This works well on stainless exhausts, but on mild steel it traps moisture causing the exhaust to rust more quickly. Exhaust heats the air trapped between it and the wrap, as exhaust cools vapour turns back to water and cannot escape.

Would VHT paint not be a better solution (or heat shields/reflectors??)

Click to expand...

I hear what you are saying but a replacement exhaust is going to be a lot cheaper than getting an engine lid resprayed. With the intricate air vents on the engine lid, it takes a lot of effort to remove any baked paint from the vents and cost wise the two options don't weigh up. If it was a car used on an everyday basis I would agree with you but most 500's aren't. Any moisture at at exhaust temperature is going to be dried out by the heat, the wrap doesn't absorb water.

My 500 air vent on the engine lid on the right hand side was trashed with dry crazed paint and really badly wrecked by the heat trying to escape via it. Which is why you see a lot of 500's with slightly raised engine lids to help cooling.

I am still going to try it out to see if it helps out.

I heard the trapped water vapour story a lot when I was asking around about cooling options. The believers couldn't actually cite an incident so the argument may be only theoretical. As these headers get up to between 200 and 300 degC, it'd be a brave water droplet to hang around for long at those temperatures, either inside or outside the piping.

However I do believe that if you just start your engine for a short period of time and don't let the exhaust get to a reasonable temperature, water can accumulate in the exhaust system and eventually rust out mild steel mufflers etc.

Your choice. I've done both over the years - wrapping and coating with no real exhaust related problems.

The headers on my Alfa are cast iron and are coated, the rest of the exhaust is thick gauge stainless. I've not had any problems for many years.

The small headers on the Fiat are also cast iron and are not coated whilst the rest is wrapped mild steel. The wrapping also disguises the peeling 'heat proof' paint on the steel.

For those in Oz, the guys who did my headers were Jet-Hot on the web at http://www.jet-hot.com.au/index.html. Friendly, knowledgeable and efficient.

As suggested, maybe I should drive with the engine lid slightly ajar or even off all together ...

Chris

I remember doing an experiment around the time that I had my Alfa headers coated and having searched my archives, I've found the photos.

I drove the car until it was hot and placed a dual sensing digital thermometer in the engine bay on the inlet side of the engine and the roaming sensor on the firewall on the exhaust side of the engine. I set the idle to 1200rpm and closed the bonnet for 15 minutes or so then opened it and took photos. I did this both before and after the Jet-Hot coating was applied. I've attached the photos.

In this N=1 experiment, the engine bay is about 7degC cooler with the headers coated. The photos are date stamped May and June 2010 so I'm guessing that the ambient air temperature would be about 20degC (early Winter where I live).

That's all the evidence that I have - must have been feeling scientific that day ...

Chris

Here's another opinion

http://www.centuryperformance.com/exhaust-header-heat-wraps-do-not-use.html

I made my decision based on the collateral damage that hot pipes would do to the engine bay contents. If the mild steel pipes disintegrate over time they will be easier and cheaper to replace than a lot of the other stuff in there.

I only wrapped the steel pipes, not the small cast iron headers, with a single layer of thermal wrap. I believe that some of the racing guys double and triple wrap the entire system from manifold to tailpipe and then red-line the engines for hours at a time. The pipes would not be the only things stressed after that sort of torture.

Chris

Interesting video, so doesn't appear to cause too much rust I think is the conclusion.

I am with Chris, exactly the same reason I am doing it try and reduce the damage caused by the heat. It does say on the instructions on mine not to over wrap the pipe. 1/4 to 1/2" maximum overlap.

Vitesse said:

.... Any moisture at at exhaust temperature is going to be dried out by the heat, the wrap doesn't absorb water.

My 500 air vent on the engine lid on the right hand side was trashed with dry crazed paint and really badly wrecked by the heat trying to escape via it. Which is why you see a lot of 500's with slightly raised engine lids to help cooling.

I am still going to try it out to see if it helps out.

Click to expand...

I can see the problem and as you say, a new exhaust is cheaper and easier than re-spraying the lid. The other alternative is a shield such as is used for fuel vapourisation on IoE manifolds but I can't see how you would attach one, and using reflective material on the inside of the lid is too visible. My problem areas have always been less visible.

On the point about heat drying out, you miss the point. All air contains water vapour. As the air cools it turns from vapour to droplets - think dew on a cold morning after a warm day. Not a problem if air is circulating, more of a problem if it is trapped. If the car is used regularly then it dries out again, if not then rust starts.

Wish I had an easy answer for you.....

Here's a cool way to get rid of some heat!

It seems odd that in 1982 I had an accessory which was a pair of adjustable covers that coud be fitted over the louvres to KEEP HEAT IN!
PS Clever pun in previous post

I've attached an old photo of a V8 being bench tested at full rpm under load. The pipes are red hot. I'm not sure whether this supports or detracts from the wrapping argument, but it is interesting and I would think that the constant cycle of heating to this degree and then cooling must do something to the steel. It certainly does to copper.

The vast bulk of the water condensate occurs on the inside of the exhaust system when the metal cools below the dew point set by the relative humidity and ambient temperature. The water is a by-product of combustion and you see it spitting out of the tailpipe after you start the engine. Whether your pipes are wrapped or not, this is a good reason to run your engines up to operating temperature frequently in order to vapourise any residual water inside the pipes and prevent rusting of mild steel exhaust systems.

It's all opinions and in the end, the choice is personal.

Chris

Wrapping the pipes makes the pipes retain more heat, i.e., get hotter than their design value. And this heat is also conducted back to the exhaust manifold. I wonder whether the design tolerance on the 500 are sufficient to allow for these excessive temperatures for long. Further, while the site in the wrapping may be dry at operating temperature, the car will eventually be turned off and the pipes will cool, trapping moisture in the wrapping. I should think the answer to bad paint performance would be a proper paint job.

I've also heard for those running old school non hardened valve seats the excess trapped heat transfers back to the exhaust valves so you can't win

So ok a quick update on exhaust wrapping. I can clearly see that wrapping the exhaust reduces the heat in the engine bay by the amount of time it takes for the thermostat to open when the car is static. Without the wrap the thermostat would open after approximately 10 minutes. With it, it takes a lot longer in fact so much longer probably 30 minutes and this is when the weather is warmer than I tested it without. Also the tick over at idle is perfect it doesn't miss a beat.

Also I can't remember who suggested getting a proper paint job but that's a pretty unhelpful answer.