I'm replacing the exhaust gasket on my 66 smoker. I have the new gasket, do I need to use any kind of goo on the gasket?
George
George
Replacing muffler gasket
- Thread starter George Tirebiter
- Start date
It would help to make sure the exhaust manifold flange is flat. Most are warped from the welding process and need to be ground or sanded flat so you'll have a good gasket sealing surface.
A hint I've suggested many times is to 'paint' the mating surface of the flange with magic marker or machinist dye then run it over sandpaper laying on a known flat surface. You'll quickly see the high and low spots that are responsible for gasket failure and leaks. You'll want a uniform flat surface for the best gasket seal. And I agree with Agreen. If things mate up well you don't need any gasket sealer (glue). Torque the fasteners to about 60 inch pounds then check them after a few heat/cool cycles.
Tom
A hint I've suggested many times is to 'paint' the mating surface of the flange with magic marker or machinist dye then run it over sandpaper laying on a known flat surface. You'll quickly see the high and low spots that are responsible for gasket failure and leaks. You'll want a uniform flat surface for the best gasket seal. And I agree with Agreen. If things mate up well you don't need any gasket sealer (glue). Torque the fasteners to about 60 inch pounds then check them after a few heat/cool cycles.
Tom
I also concur...
These flanges are usually warped right from the get go. Making sure the mating surfaces are flat and true and using a thin gasket will make for a good seal, some vendors sell gaskets that are like 1/8" thick out of that paper fiber material but these can get brittle and blow out in big chunks which makes for a huge leak right at the port where it can damage the piston rings or even the piston crown from cold shock by suckling in cold air. If you can get a hold of the steel re enforced fiber gasket material and cut your own gasket, this stuff works great and won't blow out, it's kinda tricky to cut but definitely worth the trouble.
I've had the best luck using the thin paper fiber type gaskets coated with copper gasket spray once the mating flanges were both flat and true. I'm now using a solid copper gasket that's 1/8 " thick that I made with my cnc router but these took too long to cut to produce so I only made 3 of them, but I also made 3 more that are only .040 " thick and they sealed just as well, and last year Fred was selling brass exhaust nuts that tend to hold torque a lot better than the steel ones, but if you can get some all metal self locking nuts for the exhaust studs it's cheap insurance against the nuts working loose and destroying the gasket.
If you can't find self locking nuts that are all metal in the size needed, using double nuts on each stud will prevent backing out as well. Locktite really don't work well here since heat deactivates it, but using a set of jam nuts definitely helps.
These flanges are usually warped right from the get go. Making sure the mating surfaces are flat and true and using a thin gasket will make for a good seal, some vendors sell gaskets that are like 1/8" thick out of that paper fiber material but these can get brittle and blow out in big chunks which makes for a huge leak right at the port where it can damage the piston rings or even the piston crown from cold shock by suckling in cold air. If you can get a hold of the steel re enforced fiber gasket material and cut your own gasket, this stuff works great and won't blow out, it's kinda tricky to cut but definitely worth the trouble.
I've had the best luck using the thin paper fiber type gaskets coated with copper gasket spray once the mating flanges were both flat and true. I'm now using a solid copper gasket that's 1/8 " thick that I made with my cnc router but these took too long to cut to produce so I only made 3 of them, but I also made 3 more that are only .040 " thick and they sealed just as well, and last year Fred was selling brass exhaust nuts that tend to hold torque a lot better than the steel ones, but if you can get some all metal self locking nuts for the exhaust studs it's cheap insurance against the nuts working loose and destroying the gasket.
If you can't find self locking nuts that are all metal in the size needed, using double nuts on each stud will prevent backing out as well. Locktite really don't work well here since heat deactivates it, but using a set of jam nuts definitely helps.
Dave, do you put any goo on your copper gaskets? I've found some copper sheet to use just want to ask afore I make it and install.