Correct exhaust bolt and washer set up for 1940 Roadmaster

[Drakeule]

Does anybody have a good picture of the correct bolt and washer set up for a 320 exhaust? The exploded diagram doesn't really show this.

Any help appreciated.

 

Thanks,

CD

 

 

[EmTee]

Manifold to head, or headpipe to manifold?

[kgreen]

Belleville washing positioned cup inward, no lockwasher.  Is this what you were looking for?

 

[Drakeule]

Looks a lot like mine did, before I used the weird looking washers from Old Buick Parts; Now, just waiting for the RTV to cure before firing it up.

Thanks all.

CD

[EmTee]

9 hours ago, Drakeule said:

the weird looking washers from Old Buick Parts;

Are you referring to the conical (i.e., Belleville) washers?  Do they look like what was there, or the picture above?

[Drakeule]

I'm using those weird looking things that Old Buick parts sells; are they the Belleville washers?

 

Does anybody know the proper torque spec for those manifold nuts? I can't find it anywhere in the manual.

 

Also, does anybody have a diagram or picture of the stock exhaust from the head on? Can't find that either!

Thanks,

CD

[EmTee]

11 hours ago, Drakeule said:

Does anybody know the proper torque spec for those manifold nuts?

"Snug"

 

Not too tight, but not loose either.  If there's no exhaust leaks, then they're tight enough.  Just check them following several drive cycles and snug them up as needed.  They should eventually remain snug once the gaskets take a 'set'.  I put a box-end wrench on my '38 every so often just to check that they remain tight.

[Drakeule]

But I do have an exhaust leak between 2 and 3 bolts.Right in the "valley." Got it very tight. I hope it irons out/carbons up after some time. 

 

I will keep checking those bolts after driving!

[EmTee]

Did you replace the gaskets, or just the bolts/washers?  Check that each washer is pressing on both manifold 'ears'.  Maybe you'll need to tweak a couple of the washers with a file to get them to contact both manifolds.

 

[bobj49f2]

 

When I installed the manifolds on my '37 Special I used the Belleville washers, I bought them on eBay, they were listed under Jeep parts.  I also applied the silver never seize  paste on the gaskets.  I got this information on previous posts here.  Someone suggested using a graphite slurry which never seize it if you look at the side panel of the container.  I have run my engine long enough to have to do another adjustment. 

You won't find the torque specs in the shop manual.  I got this from a MOTORS shop manual.  The shop manual says to use an 8" wrench and tighten the nuts until the wrench stops moving which is dependent on whether the person doing the tightening is 120 pounds or 300 pounds.

[EmTee]

14 hours ago, bobj49f2 said:

The shop manual says to use an 8" wrench and tighten the nuts until the wrench stops moving...

That sounds pretty close to the amount of torque I applied using the box end of my combination wrench.

[DonMicheletti]

As long as the flanges of the manifolds are of different heights, you will have an issue with getting proper seating force.

The flanges should be of equal height or the washers stepped to get the nut bearing squarely on the washer.