Im about to clean up and paint the 3800 soon and needed to know what temperature the SC housing gets. It seems that some people paint them the same color as the car and didnt know if they used automotive paint for this. Most spray paint is only good up to 200 deg unless you use high temp paint for blocks or exhaust manifolds.

Thanks, Steve

I would guess without measuring it, that it dont get any hotter than ambient underhood temps. It is moving fresh air all the time its running. Any basecoat clearcoat paint should be just fine. I think way too many people use high heat resistant paints unnecessarily. Ive used plain old Krylon on brake calipers for years and they still look great years later.

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Thanks, Specifically what I was looking at was the Grey hammered paint in a can. It is only good up to 200 deg and I am not after a show car look but I thought it would look alot better than it does now.

Steve

A supercharger housing can get somewhat hotter than 200 F. Compressing air (or any gas) causes its temperature to rise significantly ... that's why we have intercoolers ... and some of that heat goes into the housing. 15 psi of boost will result in a temperature rise of about 64 degrees F.

Check this out.

How hot is your swap? - Pennock's Fiero Forum:
https://www.fiero.nl/forum/Forum1/HTML/072858.html

quote Originally posted by sabooo: Just for fun - some Thermal images of my 3800sc engine. It is cooling down in the photo. I was looking for the true "hot spots" in the compartment attempting to ferrett out an idle issue. Cheers, Sabooo

Thanks again Sabooo!

[This message has been edited by Bubbajuju (edited 01-23-2009).]

quote Originally posted by Marvin McInnis: A supercharger housing can get somewhat hotter than 200 F. Compressing air (or any gas) causes its temperature to rise significantly ... that's why we have intercoolers ... and some of that heat goes into the housing. 15 psi of boost will result in a temperature rise of about 64 degrees F.

Too bad a M90 is not a compressor... its a blower, it creates no heat inside the case. All of the air in the blower is the same temperature as inlet air. Only heat coming from the blower is coming from friction, and its not much. Blowers using phenolic spacers rarely get over 20 degrees more than ambient.

Painting a blower GREATLY reduces its ability to cool itself btw.

quote Originally posted by darkhorizon: Blowers using phenolic spacers rarely get over 20 degrees more than ambient.

20 degrees over ambient? Those spacers must work really good, I can cook an egg on the top of my supercharger. It's way too hot to touch. Even if it's twenty degrees outside.

[This message has been edited by Bubbajuju (edited 01-23-2009).]

quote Originally posted by darkhorizon: Too bad a M90 is not a compressor... its a blower, it creates no heat inside the case.

A Roots "blower," in this context, is a compressor optimized for high volume and relatively low pressure boost ... typically less than 15 psi increase in pressure. If air is compressed (i.e. has its pressure increased) ts temperature will rise ... period. The mechanism used to compress it doesn't matter. The amount temperature rise will vary directly as a power function of the pressure rise ... greater pressure boost => greater temperature rise.

Of course, at part throttle the "blower" isn't producing any pressure boost, so there will be very little temperature rise, either.

[This message has been edited by Marvin McInnis (edited 01-23-2009).]

quote Originally posted by Bubbajuju: 20 degrees over ambient? Those spacers must work really good, I can cook an egg on the top of my supercharger. It's way too hot to touch. Even if it's twenty degrees outside.

I should clarify that I have only installed and tested phenolic based intercoolers, so it may be a bit different than the spacers.

Roots blowers compress air in the lim, not in the blower case.

Well I dont plan on using any intercooler and I know that paint can cause more heat to build up so Im not too sure about painting it at all.

On the other hand, So many people do paint them and dont seem to have any issues that I have read before.

It will stay stock so more heat from mods like smaller pulley,NOS ect... would not be a problem.

Didnt some of them come from the factory with some sort of paint on them?

Steve

The super charger gets as hot if not hotter than the engine block.
Just take a look at the PICs above. The gear housing in the SC is as hot as the exhaust tips. Exhaust tips wont hold high temp paint for to long.
I don't know how long or how hard that SC was run before the pics, but the bottom line is that the SC can get very hot. There is no way to cool down the SC without some sort of water jacket cooling system like the engine has. Both friction and compressing air heat it up from the inside out. The temp you feel on the outside is lower than the temps on the inside. The outer cooling fins on the SC radiate the internal heat to the engine compartment. If the engine compartment is hot, then the efficiency of the colling fins drop. That just means the SC will get hotter than an open air setup, but it will still build up heat from the inside and radiate it out.

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If you're worried about heat, paint it flat black. The best color for radiation of heat. And, it gives it a different look.

I used Rattlecan Caliper paint on mine and it is still holding up after 2 years now.

From all I have read on forums, the paint will decrease its capacity to cool itself, but some folks used krylon wrinkle finish paint and when the temp was checked it was lower due to the little "fins" the wrinkle paint added.. Almost like little heat sinks. Think it was the blaxk krylon wrinkle finish he used.

http://www.dynamat.com/prod...otive_hoodliner.html Maybe get something like this. That should save your paint. (I'm not necessarily endorsing dynamat hoodliner, I'm sure there are other brands as well. - Not exactly sure what the difference to regular dynamat, or dynaliner is.)

If a Mc Laren F1 has something like that to protect the paint, it's good enough for Fieros.
Note the Mc Laren is solid gold because it's the best insulator for heat, and money was no object on that car. We'll be fine with the added weight of "mere mortal solutions".

from Wikipedia: http://en.wikipedia.org/wiki/McLaren_F1

quote The McLaren F1's engine compartment contains the mid-mounted BMW S70/2 engine and uses gold foil as a heat shield in the exhaust compartment.

Jay Lenos McLaren F1
(he talks about the engine heatshields)

http://www.jaylenosgarage.c...yer.shtml?vid=187638

The thing I dont understand is what is the snout painted with? Its grey and does not seem to have faded in the least. The SC has no paint on it.

Steve

The snout is powdercoated.

I was thinking that. Well that explains it then. Thanks

Steve

Back to your original question about paint and temps.

If you think about it, the SC is covered with a plastic cover on most GM applications so it can't be getting really hot; any engine paint or brake caliper paint will work just fine. Others have used regular spray paint and body paint.

Pick a color you like and be done with it, IMHO.

Regards,

David

quote Originally posted by D2inDFW: Back to your original question about paint and temps. If you think about it, the SC is covered with a plastic cover on most GM applications so it can't be getting really hot; any engine paint or brake caliper paint will work just fine. Others have used regular spray paint and body paint. Pick a color you like and be done with it, IMHO. Regards, David

Thats just what Im going to do. Didnt think about the plastic cover.

Thanks, Steve