Headers: Wrap or not? Coat or not?

[WARP TEN]

Agree with coating. When they are coated professionally I believe they are coated both inside and out. Reduces het for sure over uncoated. I don't know who Marc used here in the Chicago are but they were well done. Never discolored in the 10k miles I put on the car.--Bob

[MuRCieLaGo]

I paid US $500 shipped for the headers. I'm not sure I want to send them and pay 50% of the original price for a coating. What do you guys think? OBX are pretty cheap...

[efnfast]

I wasn't sure either, but I did.

[ghlkal]

My SW headers are coated. As others have said, it's for temperature control. I felt it was important after researching it and getting the opinion of several folks I trusted.

[JFFerner]

If the engine compartment is cooler with coated headers,where does the extra heat go? Jim

[efnfast]

Out the tail pipe.

[RussMcB]

Originally Posted by MuRCieLaGo

I paid US $500 shipped for the headers. I'm not sure I want to send them and pay 50% of the original price for a coating. What do you guys think? OBX are pretty cheap...

IMO, don't bother with the extra hassle or cost. Use them as is for 5-10 years then if you think they should have been coated, coat your next set.

[secondchance]

Heat retention within the header is not only about keeping under hood temp cooler. When the exhaust cools rapidly after exiting the exhaust port resulting contraction of exhaust impedes exhaust scavenging.
Personally, I am not a fan of exhaust wrap because of fear of oil leak, soaked wrap resulting in possibility of fire. For this reason, I went with Jet-hot coating.

[Paul Workman]

Originally Posted by RussMcB

IMO, don't bother with the extra hassle or cost. Use them as is for 5-10 years then if you think they should have been coated, coat your next set.

I agree, Russ. It is a decision that can wait; a delayed decision w/o consequences beyond convenience of disassembly/re-assembly and some gaskets: can be done at any time, really. And, I'm willing to bet coating will never be done later, if not before the headers are installed for the first time...UNLESS the owner is a WAXER!

AND, just because of my sometimes contrary nature, (and some knowledge of physics) I don't subscribe to the notion there is significant heat retention to have practical effect on the SW or OXB (knock-off) headers in ZR-1's due to several factors:

1. e.g. exhaust velocity vs. practical heat dissipation in the relatively short length of the primary or collector tube(s), i.e., the thousandths of a second it takes the gas to pass through the primary tubes...etc, etc.
2. or the fact the majority of the tubing is shrouded; not substantially exposed to enough outside air flow to practically 'sink' the temperature of the exhaust gas (when combined with #1)

But! To each his own. No harm done, either way, I recon!

[secondchance]

Originally Posted by Paul Workman

I agree, Russ. It is a decision that can wait; a delayed decision w/o consequences beyond convenience of disassembly/re-assembly and some gaskets: can be done at any time,

Enough pain to do it once. I really didn't want to remove, coat and reinstall. But then again, I ended up pulling and reinstalling the motor twice in 16 months...