leaks around exhaust

[kirk4]

Ok,i need some expert advise(or at least some informed advise).Ihave a 75 2.0 that leaks around the connection of the heads and the heat exchanger.The brass ring gasket has been replaced and all nuts that secure the exchangers torque down tight with no loose connections.the heat exchangers are stainless and in good condition.When i bought the car it had a straight loud muffler so i purchased a bursch steet muffler.After putting on the new muffler the cars still loud and i can feel a leak around the seal.I know that its never going to be a real quiet car but i would like to stop the noise from the exchnger.Any help would be great,Im going on a year and a half and ive only driven the car about ten miles.thanx,greg.

[Conrad W Peden]

The heat exchangers can 'warp' from the heat of the exhaust. This can cause the flats where the exchangers mate to the head to be not parallel to each other. I have been told that if you take a large file(big enough to file both at once) you can file both flanges to be on the same plane. However, you need to make sure that they are still perpendicular to the bolts.

I personally wouldn't do this to stainless exchangers (they are to nice to risk ruining)but it worked on my originals.

I'm sure the guys on the post here will say yeah or neah to my suggestion.

[This message has been edited by Conrad W Peden (edited 05-25-99).]

[kirk4]

Thank you,
ive been asking everbody i could find with no luck and 3 hrs later ive got some great ideas to try.did you get this info from fat performance.thanx again for all the help I'll let you guys know how it works.

[JP Noonan]

When I got my 74 1.8L it had 2.0L SS H/Exrs. The PO didn't use a mufler bracket and about 3 nuts were missing, needless to say the car was loud. Upon inspection I noticed that one cylinder head (BTW the car had two different cylinder heads, one from a 914 and the other from a bus with smaller valves) was badly cracked, and both had erosion of the exhaust port where the copper gaskets had melted away.
Here's what I did. I used two heads from another 914, pulled out the old copper gasket (a pain, I might add) and cleaned the port sealing surface with a pick. The H/Es also had small bits of metal missing so I used a large file and carefully (as others have mentioned) filed the tubes flat. Then I used a spray copper gasket dressing, I've used different ones, they all seem to work well if you shake the can enough. I sprayed into the head port, both sides of all the NEW (allways use new exhaust gaskets) exh gaskets, and into the pipes. I've had no leaks so far (few thousand miles, and about a year).
The RTV is another way to go I guess. The highest temp one I've used is "RTV Super Copper" (like Super Black, and Super Blue), it is in a copper colored tube and is copper in color (hence the name). When I needed to pass E-Check in my 75 I didn't have any of the triangle gaskets that hook the 75 exchangers into the muffler/cat. So I used a big gob of the copper RTV to make a gasket. I haven't had time to replace the muffler (shame on me, Wanye special ordered it for me and everything) so for the past 3 months that gasket has held.

[jtnelz]

I was having loud, raspy, "cheesy" exhaust sounds from 2 liter with Bursch muffler, webers and stainless h/e. I suspected head to e/h leak but after trying a different manufacturer's muffler, problem disappeared.

[This message has been edited by jtnelz (edited 05-31-99).]

[kirk4]

just wanted to let you guys know your suggestions worked.after spending the weekend at the autocross i was jazzed to work on my car.i filed the heat exchangers a bit and added a small dab of copper sealant,let it cure 24hrs and pulled it out of the garage today.the lawnmower sound gone,i ended up washing and waxing the car.anybody know how to get rid of the bird that keeps targeting my car.thanx a ton.