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just how hot do things get under the bonnet?

Posted: Thu Apr 19, 2007 8:34 pm
by chiefbrody
my exhaust and backbox is scruffy, as are the hard intake pipes under the bonnet. Oh and the cam cover.

Question is, how hot do these places get? Can't be that hot surely?

Reason I ask is I have an abundance of high temp BBQ paint :) matt black to tidy up the exhaust and backbox (not the nice shiny tail pipe though :p ) and intake pipes, but everyones like either:

oooh, that will flake, its not resistant enough, you need engine paint (at 3 times the price)

ooooh you dont wanna do them black, you'll lose all your power, black retains heat, oooh you need to spray them silver, never do anything black :D (but black looks sooooo much cooler)

I know its not a huge issue but does anyone actually have some real advice? :)

Posted: Thu Apr 19, 2007 8:49 pm
by hcca
I would think the intake and cam cover would be fine - not sure about the exhaust though as it gets significantly hotter (like 500+ degrees if you're really driving it hard) - I wouldn't use paint at all on that - get it ceramic coated if you want it to look nice.

Re: just how hot do things get under the bonnet?

Posted: Thu Apr 19, 2007 10:00 pm
by Starion_Turbo
chiefbrody wrote:ooooh you dont wanna do them black, you'll lose all your power, black retains heat, oooh you need to spray them silver, never do anything black :D (but black looks sooooo much cooler)

I know its not a huge issue but does anyone actually have some real advice? :)

Black is actually the best colour to dissipate heat, that's why when you buy alloy heatsinks they are all black, its a proven fact.
black will draw in heat in direct sunlight but were dealing with under bonnet here.

Posted: Thu Apr 19, 2007 10:07 pm
by WidebodyWoody
I once used NORMAL paint on the valve cover, and yes it did become sticky every now and then but still the heat didn't worry the normal paint too much. The BBQ paint is fine for valve cover and intake side. I also used normal paint to paint the front valve cover on my old JA (I painted a Mitsi badge) and that was fine, never got hot.

Hope that helps.

OH and exhaust places ALWAYS spray your exhaust with a black engine spray can to make it look neater before it leaves if they made it with mild steel.

Posted: Thu Apr 19, 2007 10:50 pm
by chiefbrody
cheers dudes, thats mucho help :D

BBQ paint it is for the engine.

Im wrapping the exhaust, but its just the backbox I wanted to paint. its stainless, but covered in overspray, waxoyl, etc etc. and it would look ghetto LOL I might just give it a go and see what happens. Or get off my lazy arse and scrub it all clean :D

Ta

Posted: Fri Apr 20, 2007 9:08 am
by TOMSUN
This looks cool on the rocker cover :D

PICS
http://forums.austarion.com/viewtopic.p ... cker+cover

Posted: Fri Apr 20, 2007 10:26 am
by Alspos
chiefbrody wrote:cheers dudes, thats mucho help :D

BBQ paint it is for the engine.

Im wrapping the exhaust, but ....
Don't wrap the exhaust if it's your daily car. Your exhaust will rust away in no time.
Make a heat sheild instead if you want to protect something in particular.

Posted: Fri Apr 20, 2007 10:26 am
by jakobsladderz
I got an epoxy based paint which I have used on some studio lights (upwards of 150°C) and electrical panels without a problem. I haven't got it in front of me but it was a satin finish and on the packet said allow 24 hours to dry and 3 weeks to fully cure.. Chucked it in the oven to cure for an hour or so at ~80°C after it had dried (day or so after spraying) and ended up with a finish very similar to powdercoating - not too shiny, very tough (screws only mar the finish if done up tight) and quite scratch resistant. Got it from a local auto parts store.
That'd be perfect for non-exhaust related engine bits I'd say.

For exhaust work, go ceramic coating (expensive) or exhaust rated spray but the turbo housing and bits close to it get to 5-600°C so nothing's going to last too well..

Posted: Fri May 04, 2007 2:45 am
by chiefbrody
quick update, I broke out the BBq paint and did the cam cover and intercooler pipes, worked a treat andf looks pretty grand.

Well, better than before :)

Image

All I need now is a ton more bling and it might look presentable. But at least I'm on the way :D

Cheers guys.

Posted: Fri May 04, 2007 1:06 pm
by Marc
that painted red turbo logo looks great!. red over black . love it.

nice work

Posted: Fri May 04, 2007 1:57 pm
by TWIMCAM BOY
hey mate i use pot belly paint on my manifold and complete exhuast and its the only paint that ll last on exhuast of exhuast manifolds hope that helps