Another heat question while I'm at it...

My exhaust manifold has a few of those tell-tale cracks where the flange is welded to the pipe. I talked to Dave Lindsey about it, I also mentioned that I was thinking about wrapping the headers with heat wrap. He said that they have had good luck with this procedure to solve both problems:

1. Remove (cut) all heat shielding from the stock headers
2. Weld around the exterior of each mounting flange
3. Grind down the interior factory weld (no longer needed)
4. Have the headers heat-coated

What do you guys think? Has anyone done anything like this? I've read that there really isn't much advantage to going with an aftermarket header for these cars, so would spending $150-200 to get this "work" done be worth it? My primary goal is to repair the cracks, secondary goal is to reduce underhood temps, and an added benefit would be to retain heat inside for performance/energy purposes.

Your thoughts?

 

What material is the stock 951 header made of,actually? Never really checked the original stuff...if it is ordinary steel,a stainless header would help,even if you didn't change the dimensions. Stainless have less heat dissipation than mild steel. (..and then you Thermo-Tec it.. ..)

 

I think it's just mild steel, it doesn't look like anything fancy. For what it's worth though, I'm trying to keep my costs low, so purchasing a new header really isn't in my budget. Trying to work with that I've got at this point

 

Understandably...but you can still use the heat wrap,though,without breaking the bank. *Memo to self: Make inexpensive stainless header/crossover for sale*

 

Yes, but part of my problem is that the flange-to-pipe welds are cracked. So, rather than cobble up the inside of the pipe trying to get it re-welded, LR suggests welding from the outside and cleaning up the inside. Since the shields might interfere with the external welding, they would remove them first. Then for another $100, add heat coating.

Either way, I'm going to have to fix the cracks, and that's going to cost between $50 and $100, so I'm thinking i'll go the extra step to move the welds to the outside, and coat the whole thing after it's done. I think that in the end, the whole setup will work well and last forever.

Has anyone else done this or seen it done? Heat coating more (or less) effective than that tin shielding from the factory?

 

The entire header and cross over pipe with the excetion of the flande is stainless. I had a flange crack completly off and I had a good l9ocal TIG welder reweld the inside. It has lasted this long Also the heat shields do a lot in keeping thermal energy in the pipe and heat out of your engine bay. They had some insulation between the inside pipe and the shield too, possibly asbestos.

 

Yup its SS alright. I have had mine ceramic coated through SFR... looks nice, have not taken any underhood temp changes though, what data did Dave Lindsey offer?

 

My 1 to 4 cracked at the join section of the y. Too big of a gap to weld. Its easy to hack the heat shield off. You have to cut or grind off the welds that run along the seams of the heat shield. Discard the asbestos underneath. If you can weld it, then good. Jegs sells a header wrap that comes with a spray that you have to spray the wrap once its on.

 

The guy that Milledge buys his headers from told me that not only are they SS, but have some ti also - inconel family.

 

Even without the factory welds cracking..wouldnt it provide a slight gain to weld the pipes on the outside, grind down the inside factory welds, and then coat the manifold. (providing preventative maintenance as well as better flow?)

-Richard