Had an interesting conversation with my mechanic about increasing power/performance by lowering engine compartment air temp. Also, introducing a cold air intake.

This is a new topic for me.

He suggested ceramic coating the intake manifolds and engine tin to help. Also insulating the fuel lines and rails.

Anyone doing this?

I saw a 914 at Marina a/x last month with no engine compartment tin at all. It only had the cooling tin around the motor. You could see through to the ground all around it.

I wonder if that is a good set-up for a daily driver. Seems that a lot of cool air would swoop in there at speed. Idling, not so sure

nope ...

heat rises, the engine tin is supposed to separate the hot exhaust from the intake side. for short runs, like AX or TT, you don't need the tin but for a daily driver (or even a weekend driver), your engine would die of heat within minutes of sitting in traffic ...

coating helps where you want to reflect heat instead of soaking it in, but again, you need to be careful.
the heat has to go somewhere.
if it doesn't go into the engine tin and surrounding metal (which will be cooled by the fan) it'll heat up the intake air even more, which is not good.

Andy

Doesn't Demick have a Cold Air Intake system on his 914?
If I remember correctly, something about using a honda intake from a flaps.

My understanding of cermamic coating is that it keeps heat from tranfering through the metal to surrounding areas/surfaces. For example: the exterior of a ceramic coated header is cooler than an untreated one.

My thought is that ceramic coated tin would keep the HOT air on the HOT side. Andy, you mentioned reflecting the heat. I beleive the heat would stay contained or reflected within the tin and forced out under the car and safely away with a lower temp in the compartment.

I would hope that a coated intake would keep heat out.

The car you saw at Marina is an autocross only car. It couldn't even drive 20 miles down the highway without overheating since it doesn't even have a cooling fan installed (yes, it has a couple of small electric fans but nothing enough to maintain the engine temperature).

I did a cold air intake for my car.

http://members.rennlist.com/demick/

It's under the 4hp for $4 link

Demick

Thanks for that! D.

Were you at Marina?

yes and no

- coat the UNDERSIDE of the engine tine to reflect the heat instead of absorbing it.

- don't coat the top, paint it matte black insead. that will give you maximum heat absorption on the top side and keep your intake air cooler.

the point here is, you will get heat on the top side of the engine, one way or the other. if you modify your engine tin to reflect all that heat, the heat will warm up your intake air instead, resulting in a loss of HP, even tho you might keep the engine itself a few degrees cooler ...
hot air has a larger volume, meaning less oxigen (sp?) to burn per liter of air meaning less HP.

what you want is a combination of all of this, reflect as much heat as possible UNDER the car, where it goes into heating up air instead and that air is channeled away from the engine while you drive. btw. the "cooling" rubber flaps that were added in '74 (i believe) do exactly that!

but at the same time SOAK as much heat as possible into the metal on top so the intake air stays as cool as possible, the hot sheetmetal is constantly cooled by the fan and the intake air is as cool as possible.


soooooooooo, underside nice and shiny, top side flat black!
Andy