Frankenvette

I have yet to get my passanger side dynomax ceramic coated header to seal after a year. I have been using Mr. Gasket ultra seal gaskets. The problem is the middle section of the flange won't seal. I can only assume it is warped just a little. I spoke to Mr. Gasket tech support, and they suggest ultra seal gasket #5916 which is made for O-ring headers. If this does not seal, I am thinking of also adding some high temp red rtv to the gasket on the header side to aid in sealing. Anyone know why this would not be a good idea? The only other option that I know of is to cut the flange into three sections thus relieving the stress on the middle section of the flange (this is last resort). I purchased these headers used from a forum member, so I can't send them back.

Regards,

Jim

MotorHead

I just bought the same headers I hope I don't have this problem, someone said omething about taking them to a muffler shop to have them surfaced.

I think I found the thread by VETDRMS
http://forums.corvetteforum.com/zerothread?id=237682

It reads:

The headers go in fairly simply, i only had to make slight modifications, i recommend a good gasket, i used a Felpro. The only mod i had to do was a little grinding on the steering box flange, and on the rag joint. For some reason it rubbed on the ceramic (good way to burn something up). I would suggest you have the headers "surfaced" to make sure the flanges are flat, it only cost me $10 at the local muffler shop. THe dynomax don't come packed all that well, and are known to be a bit out-of-shape.

Frankenvette

I certainly would check to make sure your flanges are perfectly flat. I wish I had known to do this before I installed them. I could always remove it and take to machine shop, but I really hate removing it. It took awhile to get the darn thing in there in the first place.

Regards,

Jim

gearheadz

I know this advice won't help Jim, but for those considering getting a set of new headers .... GET HOOKERS!!! Its a crap shoot with the Dynos. If it isn't the coating, its the fit...if it isn't the main flange that leaks, its the collector...and on and on. When will you guys learn? Hookers are the ONLY real headers to buy!

Mark

MotorHead

I agree but by time they get up here to
CanaMexico the cost us 1000 bucks. :eek:

gearheadz

No way! :nono: That's a common misconception. The coated Hooker Comps are only a little over $300 US!! Super Comps, which are overkill for most of the cars on this forum, are expensive at over $500 US.

Mark

VETDRMS

Yeah, they were not exactly flat from the factory, but surfacing only
took 15 minutes, and was well worth it in my opinion, the FelPro gaskets
are sealing very well, i've had no problems with them :)
The left header has been in and out of the car 3 times now because of that
d#$n rag joint.

AlwaysWave

For what it's worth...Summit has 3 layer aluminum gaskets that seal really well. I don't know if my headers are straight or not, but those gaskets form fit when the bolts are tightened and I've never had a problem.

mountainmotor

Jim,
Have fixed before using GM gasket on those two ports only.Sometimes have to stack two together.Can use silicone with them but the coated ultra seals is useless to try.Won't stick.
Yep on cutting the flange in two places.
Of course let the silicone set 24 hours.If ambient is real low,after 24 hours start car for 1 minute or so then cool for another few hours.





[Modified by mountainmotor, 6:16 AM 2/16/2002]

redvetracr

Jim,
Two suggestions ! Try to get them run over a surface grinder,this will get the sealing area smooth BUT after that cut the flanges between 1-3,5-7,2-4and 6-8. All it takes is a single cut with a sawzall or a hacksaw, your flanges are warped and this should work. I cut my Hooker race headers after having them ground and it made a tremendous difference!! (easier to get the bolts started also) .....redvetracr

Frankenvette

I dont' really mind cutting the flanges. Makes good sense to me. The only problem I have is that the ceramic coating will probably peel. I hate the thought of paying for ceramic coating only to modify the flanges and have the coating come off. Thats why its a last resort. As was suggested, maybe just adding a thin gasket at the inner most section of the flange( #4 & 6# exhaust ports). A double gasket at those ports may seal it up. Kind of a bubba thing to do, but I really don't want to pull the headers out. To many other project going on at the same time on the car. Trying to get a new top installed.

Regards,

Jim

mountainmotor

Quote:
"Kind of a bubba thing to do"
Not really.Most cannot see if you wipe the silicone off before it sets.Cut the flange as last resort.