Engine Bay Temperature heat reduction

I and Lorenzo are progressing with our own experiments in this regard.
My rebuild thread has a lot of the info and some major mods done, Lorenzo may write his up soon.

But in short, oh yes baby..... are we insulating every sodding thing.

 

Instead of wrapping or insulating things, how about putting a fan on the back grill? Just a thought.

 

Dan,

A lot of clients of mine that are on the hunt for lower engine bay temperatures will use the blankets on the headers, some times paired with ceramic coating for additional protection. Then will wrap their x-pipe/rear section with the heat wrap, isolating the heat as much as possible within the pipe itself and not radiating around it. You'll hear a lot of guys mention melting e-brake cables occasionally without taking any precautions.

Shoot me a message if you have any questions, or anything I can help with!

 

Solid idea, I wonder if anyone has messed with anything like that before - pusher/puller idea?

 

Someone here already developed a fan-based solution. I think it mounted to the back of the transmission case. I'm sure you can find the thread if you do a search.

 

The thick insulation blankets that come with the Capisto manifolds do a gread job of dropping the temps.

A fan will be a waste of time, you would be better lifting the lid. What people miss with the 430 is that there are only 2 small holes in the floor to scoop up the air to cool the engine bay, the quicker you go the more cooling flow for the engine bay, reving the life out of it at a halt sigh just heats the engine bay with little air flow to cool the area.
Have a look under the engine and it is nearly blanked off

 

Header blankets and/or tape do not reduce header temperature. Header blankets and/or tape will increase header temperature. This is not a good thing.

Header blankets and/or tape will reduce radiated heat from the header, which will reduce engine compartment temps. This is a good thing, but at what cost (to your expensive headers).

 

The only way to reduce heat is to remove them from engine bay. Wrap or blanket will not do this. Depends on how long you run, the engine bay will reach equilibrium.

This is not an air cooled engine. This is a water cooled. The thermostat will regulate it to the designed temperature and maintain it there assuming your radiator works good. Engine bay temperature will be higher of course, but it will reach equilibrium at one point. Unless heat is removed from the engine bay.

 

You are not going to overheat T309 manifolds just because they have insulation pads on them, thats like saying you dont insulate the pipes in a turbine plant and i served my time on them, plus 20 years. They use T 309 in gas turbines, even T304 in used in the far east made manifolds will stand up to insulation pads.

 

What a load of rubbish, the difference in temp in my 430 engine bay is huge with these blankets fitted. These are fitted around the manifolds, not the water jacket of the engine.

As to what the thermostat effect is on the engine bay temp, i dread to think. You will reach equilibrium ?
What with- an iceberg !!

 

The claim of equilibrium isn't correct; it implies that at temp blankets make no difference. The motor block is at a fixed temp as described above. The headers and cats are VERY hot. The grills and vents provide an exit for heat. Blankets introduce a high thermal resistance between the hot and the engine bay. That in effect, slows the migration of heat from the header into the engine bay. Assuming that the engine bay's cooling remains the same (you didn't plug vents), the temps in the engine bay will drop with blankets because more heat goes out the exhaust pipes and less migrates into the engine bay.

This is a basic thermodynamics problem.

 

I am in the habit of raising the engine lid and running a powerful fan after I put the car in the garage. Man, there is a lot of heat in the engine bay. Anyway, I know that there are a lot of solutions but this is what I have done since I purchased the car. I find that a winter's drive doesn't necessitate this method, however. It gets into the 20's here. We seldom have snow here so I enjoy driving the ride in this kind of cold.

 

Well said, some common sense.

 

I wonder if anyone has experimented with removing the bonnet glass, and replacing it with a perforated material, not unlike the challenge grille? Of course, this is more functional than esthetic. But, as hot air rises, would have a similar effect to popping your bonnet all the time.
I agree with others, that blankets, wraps etc don't make heat magically disappear....it just contains it or moves it to somewhere possibly more desirable. But there's always trade offs.

 

Have you got a challenge rear grille? I fitted one to my 355 and the engine ran much cooler leading me to believe that all 355s should have been shipped with one from new.

 

This was done in F40 already =)

 

I agree it slows it. Like I said, over time it will reach the temp regardless. Otherwise a challenge grill which allow hot air to escape or opening the hatch won't help.

the purpose of the fan is to extract those hot air.

 

Back to the OP's original question...

Heat is not a good thing, and over time it does real damage - so it needs managed and something has to put up with it in the end. The choice of the engineer is to decide 'what' puts up with it.

Go and have a close look at the heat shield material on the side of the fuel tanks - i bet you find it to be totally knackered and cooked like over done bacon.


So what are your goals....
1. Protect the surrounding components from excess heat eg F1 power block
2. Lower Air Intake temps.
3. Better control over oil and water temps.


Headers
As for what is best, there seems two solutions;
a) blankets - Capristo/Fabspeed or make your own. ( i went with Fabspeed as they had a sale on )
b) cladding - i'm always forgetting the link - but you have to send your headers to them.

Ceramic coating (spray on) = what most places offer / largely cosmetic / no major heat reduction.
Ceramic coating (plasma dep) = it works / not sure anyone in US does it / about 30% reduction.
Exh Bandage wrap (old style) = it will break up within a week
Exh Bandage wrap (titanium) = not tried it / so unknown.


Cats
Well, Capristo thinks it worth while to offer blankets for those too.
I did mine with my own solution / others are also doing this.


Muffler
Capristo does offer a blanket for their muffler (special order if i read correctly)
Again i did my own. The muffler had a hot spot of 250C, but with my blanket the outside is now <70C.


I went further with other mods, more than most would be comfortable with...but I have +10yrs of experience of racing cars at places like Zhuhai and Sepang which are unbelievable hot - so i took that experience and applied it.

This past week it has been 39degC outside and i was able to drive my car in heavy traffic and my gauges stayed exactly were i wanted them to stay, which is certainly not what used to happen, and after a drive i can put my hands down the side of the engine and touch the blankets without getting 3rd degree burns.

 

Nice. I wonder about making my own "lids" as opposed to full blankets. Something like a heat shield mounted to the header but with plenty of airflow space to the side and below.

I also like the idea of fans. Are there small PC or Power Supply fans that can take the heat but still fit on the engine cover? I mean mounting a fan on each side the vent slots beside the glass. To PULL the air out of the compartment at stop and slow speed. Yes the under panel for aerodynamics closes up the bay. The NACA ducts/chimneys are useless when the car is not moving. A pair of fans would keep the air moving. I and some other folks have added washers to the bolts. 3 layers lifts the under panel about 6mm off the chassis opening a slot for the air to convect through even at a stop. I left the front edge flush for laminar flow

 

That's the point, it won't reach the same temp no matter how long you wait. Think of it like water. The vents let water out at some fixed rate. The headers and cats put water in at some rate. IF I put a flow restrictor on the input so the water moves into the compartment more slowly but make no change to the out outlet, is there more or less water in the compartment. Will the compartment eventually be the same amount of full? Hint: the answer is no in both cases.

In the case of blankets the exhaust gas is actually hotter when it exits the tailpipes. That is where the extra heat goes. That means there are just less BTUs put into the engine bay for the fixed cooling to remove.