exhaust leak
Thread Starter
Racer
Joined: Dec 2007
Posts: 445
Likes: 2
From: Thomastown Mississippi
exhaust leak
1977 Vette/350 engine. I bought my Vette last April and it had headers on it when I bought it. Car runs real smooth but it does have an exhaust leak. It's on the passenger side. Seems to be coming from the middle two cylinders where the header bolts to the engine. If I put my hand just above the header, I can feel air pushing out in that one spot. Makes a phit, phit, phit sound. I replaced the gasket several months ago. First with one of those aluminum foil looking gaskets they sell at autozone. Helped a little, but not much. Last night I installed a regular exhaust manifold gasket. Still no better. It's not a severe leak, just enough to be annoying. I'm guessing maybe the header is warped where it bolts on. Not sure. Any suggestions other than buying new exhaust? Thanks,
Kenny
Kenny
Instructor
Joined: Jul 2007
Posts: 228
Likes: 0
From: Price Utah
header gasket
I'm not sure what header gasket you installed from Autozone , however there are aluminum and copper gaskets made which compensate for uneven header flanges. They tend to be more expensive than regular header gaskets. I got mine at Schucks and though its been a while it seems they were about $40.
Good luck
Good luck
Instructor
Joined: Sep 2007
Posts: 126
Likes: 0
From: Dallas Texas
you bought the right ones, just soak them in water for 20 minutes to 1/2 an hour before you put them on - works like a charm! one other small detail that i think is important - use a torque wrench and torque the bolts down to 25 ft/lbs.
Le Mans Master
Joined: Apr 2005
Posts: 6,355
Likes: 425
From: Seattle Area WA
There is a pretty nice extra thick graphite gasket available that works great for troublesome headers. They are made by Remflex. http://catalog.remflex.com/category_s/94.htm
Also when torquing, start with the middle two bolts first and work your way outward, and start upit torque low, say 10 pounds and work your way up to 20-25. I also use hi temp loctite on bolts too.
Also when torquing, start with the middle two bolts first and work your way outward, and start upit torque low, say 10 pounds and work your way up to 20-25. I also use hi temp loctite on bolts too.
