I'm going to look at a set of used Z06 Melrose headers for my LS3 tomorrow. I've read they will fit, but my question is about the finish.

According to the one site I could still find them for sale, Melrose headers are ceramic coated. I don't know the condition of the headers I'm going to look at and want to know what I'm getting into if they have surface rust. If they have rust on them, can they be sanded and painted with Cerakote?

Would wrapping them with header wrap be a better option?

Paint and wrap??? So many options. I've never bought headers before.

I'll be buying new GM gaskets and bolts for the install, I'm assuming I'll also need 24" O2 extensions too. My starter is already wrapped to I'm hoping I don't have any issues there. A tune of course.

Am I missing anything else? Do I need any protection for the spark plug wires?
​​​​​

 

If headers are not coated to start with, cheap bucket type sand blaster,
https://www.harborfreight.com/portab...kit-37025.html
Air compressor, respirator,and a bag of play sand from home depot, is all you need to blast the headers to get them ready for ceramic coating out in the yard.

Next, ceramic header coating can be had in both air dry,and heat cure. So since you may not have a oven big enough to bake them to cure the coating, your looking for air dry ceramic coating to shoot them instead. So once you wipe down the blasted headers with acetone to get them clean, can start to shoot the coating.

If all this is past your skill level, then check locality for a shop that can ceramic coat the headers instead.

As for blanket wrapping the headers, look like hell in the end, and will still need to be a heat shield on the starter so the header heat does not burn up the solenoid on it.

If they are coated, but starting to rust, then could use cerakote, but you do need to prep the surface to remove the rust, as well as get the metal in a state to accept the coating (see oxide sand blasting above).

As for rear O2 sensor, since the high flow cats are moved down line of the header collector in the X pipe, your going to do a delete of the rear o2 sensor. The post cat sensors only monitor the cats (pre cat sensors needed for the actual car tune), and since the high flow cats have been moved down line farther from the heads, not enough differential reading between the pre and post sensors and will be getting codes with them still in play.
Note, run high flow cats in the X pipe,to keep the cabin from selling like unburnt fuel when stopped at a light with a tail wind/ or gassing out the person behind you at a light. The high flow cats are only going to rob you of about 3HP total with them in play.


Also headers will cause the motor to run leaner at WOT when the motor is running in open loop,

So will need to have the car tuned, and they will turn off the rear O2 sensors.

If for some reason you still want the rear O2 sensors in play (really just for looks and will need the extension cables) then you need to pull them out of the exhaust stream so they will have a lower reading to not trip codes of the high flow cats in the farther back location not being efficient enough.


To add, what are your plans for the X pipes, if they are not coming with the headers. Also if this is a z06 system and coming with X pipe,then output on the X pipe will be 3", while base type muffler pipes are 2.5" instead.

And yes, get 2500* spark plug wire insulator boots, so you don't burn up the wires/boots from the header heat.

 

Thank you for the novel, Dano. Always appreciate your detailed reads.

I need to stop by my emissions shop tomorrow and ask them what I should do about the rear O2s. I want to be legal so if tuning out the rear O2s is not OK then I'd like their recommendation.

All the coating options you shared are in my realm of ability, so I will keep that in mind when seeing the headers tomorrow. I'll stay away from the wrap.

They are the headers and the x-pipe. I'm planning to use an adapter to mate the 3" x-pipe to my 2.5" muffler pipes. There is only one photo and it looks like the x-pipe has cats but I will confirm tomorrow. I definitely want to keep it catted.

 

I have kooks headers that I recently re-wrapped using the lava-rock based header wrap. It is a bit of a bitch to wrap headers but it does cut down on the heat a lot.

Would like to to a Je-Hot coating but I don't want my car to be down for several weeks while I wait on them.

I used the DEI product black titanium wrap. Then I painted them with the DEI high temp silicon coating. Came out quite good.

 

Don't use header wrap, get them ceramic coated. As the old saying goes" you get what you pay for" so buy a quality set of headers like Kooks or American Racing Headers

 

There's no problem with wrapping if done right and from multiple testing the wrap is much better at keep engine bay temps down than the best ceramic coatings would. These aren't off road cars where you will be soaking the wrap in water (Unless you drive in the rain) and retain moisture. I've had exhaust parts wrapped for 10+ years and no corrosion or cracking what so ever like some people like to say but that is just my personnel experience, there will always be a debate on this subject.

 

Melrose Headers have great reviews from what I have been able to find, they just don't sell them anymore so they don't appear to be as well-known. I didn't know about them until this week. Do you have firsthand experience with them?

 

Well, I bought them. Really nice older gentlemen who said he knew Ranger... As in Ranger method Ranger.








What are these extra holes welded in near the front O2 sensors?







Also, I was expecting D shaped ports but they are circles, so what gasket do I need to buy?




The cats look to be in good shape.




Headers appear to be 1 7/8 with a 3" x-pipe so it's what I was looking for.

 

Standard GM exhaust gaskets will be fine.The extra ports were put in so they could install a wideband 02 sensor.

 

Extra bunges added for wide band O2 sensors.


If you want to shoot them with anther coat, then actone tone and steel wool, will prep them for a coat of air dry Cerakote.

Rear O2 bunges are already capped, but if you need to put the rear O2 sensors back in play for visual inspection and working, then adaptors to pull them out of the steam so they read lower to not throw codes (or just install them like normal, and still turn them off in the tune.
Hence only pre-O2 sensor work with the tune, and the post O2 sensors just monitor the cats to make sure the are still working effectively or not.

 

I Cerakoted a set for my buddy and my own, very happy with the results and both cars are holding up great even after a few months. We actually debated adding it as a business aspect on top of wrapping cars but its just to messy to run out of the same shop with overspray. If you decide to go that route though let me know. Your close enough I'd be happy to do another set. It may be my imagination but i swear its done a better job at moving the heat out of the engine bay and into the exhaust. Use to feel the header heat at my feet and now I cant as much.

 

Thanks guys. I assume I'm looking at a plug in the wideband ports too? Doesn't look like the same plug as the rear O2 ports have but it's definitely not open soooo

Buddy of mine said his neighbor could re-do the welds on the wideband ports. What say you? They are clearly terrible looking welds but I know enough to know even a bad looking weld can still serve the intended purpose.

Thanks @StayinStock , I am interested in re-coating them but not sure when. I don't even know when I'll get these installed. I really just got them knowing I'll want them when I eventually add a supercharger and the deal was too good to pass up. I called two shops to get tuning quotes and one was $750 and the other was $1060. Seems it would make sense to just wait and do everything at once.

 

Shoot me a PM, I know a great tuner in your area but he doesn't advertise anymore since its his side gig. I'll get you guys hooked up, he's down in culpepper

 

Moved these headers into a storage area at my house when I was setting up the Christmas tree this year and noticed one of the cats has movement in it. One hardly moves but the other you can see has quite a bit of play:


They shouldn't do that right?

Assuming this is not normal, are these my best options?

1. Remove the material entirely to run catless (I'm not doing this)
2. Buy new cats and have them welded in.

 

That is a lot of movement! I remember reading people melt cats with forced induction. I've been out of that for a long while maybe someone can chime in about it.

 

Agreed, shouldn't move that much. Would go with your second option, buy and weld in new cats.

 

Thanks for the confirmation. If I'm eventually going forced induction, I should just spring for the Kooks green cats now vs trying to get away with high-flow cats, right? High flow cats aren't going to survive but the green cats should up through my power goals (definitely not more than 700whp but aiming for right around 600whp)?

 

I may have already asked you this so I apologize if I did, but did wrapping your headers cut down on valvetrain noises at all? I’ve read before that it makes a noticeable difference and I was considering it just for that reason alone. I know there’s some cons to wrapping but if it will quiten down my rattle trap I just may do it lol

 

No problem. Yes, it does indeed quiet the sound a bit.

 

Earplugs will lessen the valvetrain sound/noise far better and with a lot less expense and labor. If that doesn't work, then you have a much bigger valvetrain issue to resolve.