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cchan · Post by **cchan** » Sun Nov 26, 2006 12:34 pm

Hello,

Just wonding what the Forums thoughts are for colors for headers. Should I go with Blacks one to match the valve covers & plen. or go with Titanium for a contrast. My Alfa is Candy apple red. Thanks for your input and I am posting some pictures.

Mezevenf · Post by **Mezevenf** » Sun Nov 26, 2006 6:53 pm

I say black, and I'm jealous of what you've done with your covers and plenum.

I might copy you

Sporttunergtv6 · Post by **Sporttunergtv6** » Sun Nov 26, 2006 8:03 pm

Are those paint colors or hi temp coatings like jet hot?
instinct says black b/c the motor is just a hunk of aluminum.
v

Barry · Post by **Barry** » Sun Nov 26, 2006 8:18 pm

Ive had a request for white...like the old Ferrari`s from yesteryer racing...with very dark covers..

cchan · Post by **cchan** » Sun Nov 26, 2006 9:30 pm

They are Ceramic coated. The only difference is the color and my understanding it that they were heat treated when they were colored. I think this is similar to powder coating. I am just tring to decide what color I like better. Thanks for the input.

junglejustice · Post by **junglejustice** » Mon Nov 27, 2006 9:56 am

...you're welcome Chuck...

Told you it would look nice...

I like the white Barry - if it is on a very clean engine that does not leak any oil! (Worst is when you get that burned-on little dribble of oil running from the head down on the white header...) But I assume that you know how to build an Alfa motor that does not leak oil!

Bernard - your engine-bay looks beautiful - what are you talking about!? Post another picture here please! (After you give Chuck your opinion on header colour...)

The covers are done in a 1600* non-ceramic, thermal heat-dispersant coating that helps to radiate heat. (It only comes in that one finish - that shiny black gloss - which is what gives it the thermal qualities that you are looking for in a valve cover.)

Some other types of powder coatings and ceramics - even regular paints in other colours - act as an insulator (in effect increasing temperatures down below, the oil and on the bearings.) Again, this is in theory - I don't know just exactly HOW MUCH it effects it. To be safe, I listen to the man and now I go with this finish on every valve-cover that I touch from here on out...

The plenum was done in a 2000* ceramic thermal heat-barrier which (again in theory), helps to keep the induction temperatures down. After moving the oil-filler neck on the left-side valve cover to the front for easier access and out of the way of the brake-booster, I had the cut-out for the new position of the oil-filler neck machined in to that little coil-pack cover that comes with the 164 motors on the front head - just for aesthetic purposes.

I matched the coil-pack-cover to the plenum's finish for no reason other than a symmetric look! I then block-sanded down all of the cooling fins and "Alfa Romeo" & "V6 24v" script with 80-grid - it just POPS! I like the matte against the gloss however, with the plenum and cover installed, you don't see too much of the valve-covers.

By the way; with the way that I am setting this one up - we dumped the coil-on-plug setup. The coils that Alfa uses are sensitive to heat and vibration and I have had them fail on my stock road cars at somewhere as low as 40-50K miles!!! We are mounting 3 x double Mitsubishi Pajero coil-packs remotely on the fire-wall - away from the heat and vibration of the engine...

Back to the headers; these again are done in the 2000* thermal heat-barrier (again in an attempt to keep engine bay temperatures down, protect them and keep them from rusting (since they are mild steel), but also as a theoretical performance enhancement - keeping the heat inside of the header (according to the manufactures of the coatings) increases the velocity of the gasses through the header and enhancing performance!

Question is; for the headers - titanium (sort of a greenish-silver), or matte black to match the intake plenum and coil-pack cover...? (Chucks car is a beautiful metallic red - close to what my early 90s 300ZX was.) Very nice - the black looks good with it, but maybe we need something else in there...?

cchan · Post by **cchan** » Mon Nov 27, 2006 1:50 pm

Thanks for the clarification Jungle Justice. As you can see, my corporation is just paying for these extra options and I definately wanted a professional guiding us with the engine upgrade.
We probably could have done the conversation ourselves but with my time constraints and lack of knowledge on the modification, we voted to hire a consultant.
We hope that this path will lead to a very professional restoration of my Alfa when everything is said and done.

BigKriss · Post by **BigKriss** » Mon Nov 27, 2006 8:53 pm

'By the way; with the way that I am setting this one up - we dumped the coil-on-plug setup. The coils that Alfa uses are sensitive to heat and vibration and I have had them fail on my stock road cars at somewhere as low as 40-50K miles!!! We are mounting 3 x double Mitsubishi Pajero coil-packs remotely on the fire-wall - away from the heat and vibration of the engine... "

Can I speculate as to perhaps why the coils are not lasting in your application?
You are coating your cover with "ceramic"2000deg coating.This ostensibly to get radiate heat away from the engine.
You then put another "ceramic"2000deg coated cover over the coils.Again to radiate heat away.
Call me dumb.but what you are doing here is creating an oven in which the coils need to live.
My BMW has individual coils and they have never been replaced due to problems as described above.
The best coating on covers is realy no coating at all.Natural alluninum has the best radiating properties.

Experiment:
1x black coated plate
1x white coated plate

Put both in nice warm sunshine for 1/2 hour only.
Measure temps.
My nuts are on the white plate being cooler.

I see you have been grilled on this forum.This is not my intension here.
I just dont fully agree with your explanation of events here.Perhaps you can enlighten me?

Jim K · Post by **Jim K** » Tue Nov 28, 2006 4:46 am

Big Priss,
I read you have a BMW (you can't be all that bad)...you see its like black coffee and coffee with cream...the black one cools quicker...if you don't believe me, take your nuts off the white plate you mention and put them in the hot black coffee, then repeat with the cream cup! Please report results.

Jim K.

junglejustice · Post by **junglejustice** » Tue Nov 28, 2006 6:23 am

BigKriss wrote:Can I speculate as to perhaps why the coils are not lasting in your application?
You are coating your cover with "ceramic"2000deg coating.This ostensibly to get radiate heat away from the engine.
You then put another "ceramic"2000deg coated cover over the coils.Again to radiate heat away.
Call me dumb.but what you are doing here is creating an oven in which the coils need to live.
My BMW has individual coils and they have never been replaced due to problems as described above.
The best coating on covers is realy no coating at all.Natural alluninum has the best radiating properties.

Well, grillings aside (some perhaps due to the same mis-communication that you and I have here) - if you re-read my post - I specifically stated that I am using a 1600* NON-ceramic coating on the valve covers (not pictured here...) It is a coating which the manufacturer claims will specifically decrease under-side temperatures of a treated section of aluminium.

The 2000* ceramic-based coating used on the intake plenum and coil-pack cover (to match) is rather inconsequential for the following reasons;
1) We are cutting away the base of the intake plenum that normally covers the coil-packs on the rear (right-side) head in a 164. It is not quite visible from the top however, with the plenum off and flipped-over, it is very clear that there is not any heat getting trapped underneath that side.
2) The little (what used to be) coil-pack cover that sits over the front (left-side) head in the standard road car application is normally installed on "insulators" in a "stand-off" position from the valve cover! There is sufficient space all around the edges of the cover. In addition, the cut-outs (arches) normally there to facilitate the harness containing the coil-pack leads and injector leads to the front head, as well as the openings for the injector leads from underneath that cover out to the injectors are all now completely empty/open which also provides a degree of "breathing" I would imagine...

Furthermore, don't know if the BMW (and the particular model that you are referring to) uses the same part-number/issue of coil-pack as the particular units used in the US-spec 1994/1995 164 LS 24 valve cars (I highly doubt it) however, these fail all of the time on these cars. (Just take the little front coil-pack cover off and turn the lights of in the garage - just love that light-show of the coil-packs arcing to the heads - solved by replacement units!

In your experiment/example - the reason the black plate feels hotter than the white plate is because it is radiating more of the heat imposed on it by the heat-source, rather than absorbing it... (Oh God! Here comes the scientists and the gurus and the engineers and the experts- gotta go!)

Last, neither of the engines on my two road cars that have had the coil-packs fail, had coated anything at the time. Hope this clears up my post.

Jim, when you get your nuts out of the coffee, say "Hi" to Ron for me...

Now back to Chuck's question - titanium or black on the headers?

Mats · Post by **Mats** » Tue Nov 28, 2006 6:41 am

Nah, the reason to the black plate being hotter is because the black one absorbs the radiation better, but it also radiates better and in the case of the plenum cover it means that it moves the heat away from the material better.
This of course only if you have some kind of shield that prevents it from picking up the radiation from the headers, otherwise you're in trouble.

junglejustice · Post by **junglejustice** » Tue Nov 28, 2006 7:19 am

...good point Mats... (All the more reason to also do the headers in the ceramic thermal barrier to help keep the heat from the gasses inside of the headers...

Mats · Post by **Mats** » Tue Nov 28, 2006 9:34 am

I have no personal experience with header coating but I hear it's good at keeping the temp down. I would still put a heat shield over the headers though, even a very thin sheet of metal would do it. Even if it's colder with the coating I'm not convinced it removes enough heat radiation to make the coating on the plenum the right one.

cchan · Post by **cchan** » Tue Nov 28, 2006 10:23 am

OK, Thanks for the information guys, I went with Titanium since we decided that we like the look better. Very scientific. Oh well, what to you expect from my wife. The artist.

Black or Titanium Color Headers