Exhaust Gasket Sealing

iamchappy · iamchappy's Garage

I have had trouble in the past getting the Stainless Steel exhaust gaskets to fully seal on my headers. I have filed them flat as i can but I still see some carbon leakage from a few of them when there removed. Should I use a copper sealant or something to help seal them up better.

sww914 · 09-26-2006, 08:22 AM

A lot of people will probably say not to use anything, but I say it's worth a try. If everything was perfect, you shouldn't need to, but obviously something isn't perfect. To surface the flanges on the headers you really need a big belt sander to get all of the flanges on the same plane, as they are on the heads.
A little O2 sensor safe copper RTV might help, and the worst case scenario is it will make a little bit of a mess here and there, and burn up and turn into carbon.

CBRacerX · CBRacerX's Garage

I have used Curit-T on these with good results.

patkeefe · 09-29-2006, 06:10 PM

Does this mean the beast is running?

iamchappy · iamchappy's Garage

I picked up some copper sealant, but also may purchase a set of BB heat exchangers. My headers I am sure are the reason I have had some problems in the past getting a good seal on a few of the flanges.

In answer to Pats question "Does this mean the beast is running?"
Not yet but soon, the car entered the body shop yesterday and were going to bust hard on it the next two weeks. Thats also one of the reasons for considering heat exchangers as I may end up driving it till the snow falls to ensure all is right with the engine and get it broken in.

Good heat and defrosters in the cabin maybe needed.

I may have to invest in some Blizzacks as the RA 1's will be like driving on ice skates.

patkeefe · 03-15-2007, 04:08 PM

Chap:
Did you ever try the copper stuff on the exhaust gaskets? I have to put mine on tomorrow, and I'm going to pick up a can of the old standby Permatex copper coat. I also filed my flanges on the heat exchangers really flat, as they were pretty bad. I don't want to take this apart again if I can avoid it.

Chris:
I have some Dow Corning 111 (same as Curil-T, I think). I'll check the heat range on that.

Thanks!
Pat

iamchappy · iamchappy's Garage

Pat, I did use the copper sealant on the gaskets but I cant tell you how it worked yet, the cars still not together, still in the body shop. I must say it made installation easier as everything was stuck together. I went with the stock heat exchangers on my 914 so the flanges have a raised ring that seats into the gasket, but i still used the sealent.

patkeefe · 03-15-2007, 05:21 PM

Chap:
I just put the heat exchangers on...stock 911 HE's. I used some of my $30/can Nickel Anti-Seize on the gaskets and studs. I think this should work out OK. I'll know in a couple of weeks and let everyone know how it does.
Thanks again!
Pat

iamchappy · iamchappy's Garage

With the heater boxes on its so damn hard to tell if anythings leaking. Hopefully the sealant helps, and not hurts the sealing issues.

patkeefe · 03-15-2007, 05:55 PM

Can't hurt too much. The flange was leaking badly at every one of the exhaust ports. I have hours of filing time in on those HE flanges. Also, I think I've paid way more attention to the fittment of the HE's than I did last time, and made sure I took all of the pre-stresses out of the system.
Anyway, by next year, I'll probably want something with better flow to spool faster!

iamchappy · iamchappy's Garage

I think my tiny diameter HE's are going to get that K27 to zip up in a hurry!
I just hope they can flow enough exhaust on the upper end.

OldTee · 03-15-2007, 08:33 PM

Same thing happened to me. I took em to a Machine shop and had them do their magic. cost $50 a side but it was worth it. Put 24K on it without leaking.