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When I took my engine out for rebuilding I noticed that some of the concave/convex washers that go under the brass nuts weren't on the same way. Some had the convex side toward the manifold and some the other way. I meant to ask which was the correct way but forgot. Now that I am finishing up the engine installation I want to know which way is correct. Does the convex side go toward the manifold or away?

I believe the concave side goes towards the manifolds. That is how it was on my motor. So the nut is pressing on the convex portion, and the clamping load is being distributed across the outer edge of the concave side.

Tis thanking muchly I am.

I didn't know Yoda subscribed to this forum!

Randy,

It's part of our Jedi exchange program.

Brass nuts are preferred over steel nuts to fasten the manifolds to the engine. This would be a good time to install a new set of them.

(o{I}o)

Brass nuts are preferred over steel nuts to fasten the manifolds to the engine. This would be a good time to install a new set of them.

Good reminder, JW. In fact brass nuts were OE (original equipment) for many years on Packard manifolds. And just to emphasize what's already been said, the manifolds must be able to "slide" ever so slightly against the block as they expand/contract differently, so proper torque is very important, and metal-faced gaskets are definately preferred over the composition type.