Exhaust/Intake Manifold Clamp Plates and Nuts

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Season’s Greetings to you all!

One of my winter projects is a new ceramic coating on the Pierce’s exhaust manifold. I spent last evening looking through the PASB CD library and really did not find anything on how to re-install the manifold set on the ’31. Specifically, I am looking for the correct orientation of the “D” shaped clamp plates that go over the studs and apply pressure to the ears of the Exhaust and Intake manifolds. I sketched how the clamp plates were oriented before I removed the nuts….but they seemed to be rather randomly oriented, maybe they rotate with the final torquing of the nuts due to friction.

The next thing I am wondering about is how much torque to apply to the nuts that retain the manifolds on the studs on the side of the block.

I also need to know the torque for the nuts that hold the 2 manifolds together.

Beyond the clamp plate positions and manifold nut torques, if you have any input, clever ideas, lessons learned, experience or preferences with the various coatings on the market, “don’t try it this way”, etc., send them to me, and I will put an article together so that other members can benefit.

Thanks for the ideas.

Happy Holiday Motoring,

Chris

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Chris did you machine the surface between the intake and exhaust? The manifold moves quite a bit from hot to cold aglong it’s length. Also, did you make a block off plate for the heat riser? The standard for torque on the bolts (by size) for the ones holding the two manifolds can probably take more than the ones holding it to the block. On my cars I have just done them by feel, staying light as possible figuring I can tighten them up if necessary, not wanting to crack the manifold. Is your exhaust manifold new or old?

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Sorry Chris I cannot comment beyond what Ed has said. I have fitted one of Dave Murrays new manifolds to our 1929. As you know those “D” thingos do not have any real locating system & mine turn when tightened. I try to preempt the amount so that they finish somewhere in line when tightened. I agree with Ed re the amount of torque. BUT I seem to remember somewhere in the PASB stuff a list of torque settings that list the manifold nuts. Old age precludes where!!

I used some “Magic” modern manifold gasket material. FAILURE!! With the amount of hot/cold movement of the manifolds , it has cracked at #1 & 8. The gasket NOT the manifold thank goodness. I had only driven 500 miles. Next question

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who supplies Copper “asbestos” manifold gaskets these days?? Dave M does not have any.

Again from 98 degrees warm in The land Of Oz enjoy your snow Chris!!!

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Jak, Olsens Gaskets should have the manifold gaskets you need. They are listed in the parts supplier directory. My best, Ed

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Chris,

The clamp plates should be set with convex surface contacting the nut and the inside edge that contacts the manifold should run vertically so that each edge contacts only one manifold ear.

Make extra sure that your ignition timing is up to spec and that you only drive the car in full advance position. Heat is the enemy of ceramic coatings on the exhaust manifold and the quickest way to ruin it is to run the engine with retarded spark ignition.

Bill

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Hi Chris,

I’ve had good luck with Custom Ceramic Coatings in Lenzburg ILL. John was less expensive than others in the field and so far the results are quite good.

Happy Motoring,

Rick

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Thank you Ed. Keep driving your Pierce Snowmobile. Jak.

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We did another 65 miles this afternoon and evening. 28 degrees and the top was down. I am still cold 3 hours later.

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And so the Case of The State v. Edgar R. Minnie II was proven!! Well done Ed—- this is what our cars were designed for I guess. Jak.

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