sr-71

Hi guys,

just put a brand new Spoon header on the ITR yesterday and I haven't powered the car yet.

Maybe I'm just getting old and confused, but I remember reading a post here in this section(searched and couln't find it) about 10-15 years ago and someone posted a pic of his new ITR header that was glowing very bright red...IIRC some people mentionned in the discussion that it does that only once, on its first use...is that correct or was I dreaming?

I'm going to wait until it's dark tonite and snap some pics or I might even film it if does glow, so I can share after.

Assuming it's true, I guess the header would have to become pretty hot before it glows...so does anybody know how long it takes? About how long does it glow? can I just idle the car for a few minutes, do I have to rev the car a little or do I have to go for a spirited drive or even drive it on the track and immediately open the hood to snap some pics?

Thanks

boarderfatty

iTrader: (1)

lol, just no.

It will get red if it gets hot enough, nothing to do with first use.

Since you just installed a new header, make sure you wipe it down really well with a solvent based cleaner that does not leave residue. (Even windex would be fine) to remove all the finger prints and oils of they will be permanently left on your fancy new header.

sr-71

cool thanks for the quick reply!

I confirm that the only thing it did after 2-3min on idle is that it just turned slightly goldish and after a 30 min run on the highway it's just a little more golden in color.
It didn't glow red at all at any point.

Don't know why I was sure I read that years ago, oh well. lol

94eg!

iTrader: (2)

The gold color is an oxide layer forming on the surface of the stainless. The hotter the pipes get on their outer surface, the more that surface color will permanently change. Eventually they usually end up in the bronze area with some purply hot spots. If you don't like it, you can always refinish them with a green scotch-brite. Just clean them well before putting them back into use, because oils on the surface create blue hot spots.

btw: Metal won't start to glow (visible in the dark) until ~752*F, and gets brighter as you go up.

sr-71

Wow! Super interesting info, thanks.

Yesterday I went at the track and immediately after the cooldown lap following a 20 min session the header temp on each tubing was only around 305F +- 2 deg, so not even close to glowing temps...or at least when parked.

Good news is all four cylinders temps at the exit are the same and the header is colored evenly all across the 4 sections.

thadon805

iTrader: (3)

94eg! , good info/pic !

boarderfatty

iTrader: (1)

Note that the oxide layer can only form under the presence of active gasses (IE: Oxygen). In a totally inert environment the color of the steel will not change regardless of maximum temperature achieved, cooling rate, etc.

Usagi Yojimbo

iTrader: (1)

That picture was actually a Toda header on a fully built ITR motor, in a 92-95 hatch. They had it on NWP as the main pic, a while ago

subtlecuddle

iTrader: (6)

good info, thanks for sharing!

3uroR

Great info about the colors of metal as temp rises, as for the OP I've never had this experience.