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Dimensions Of These Ports?

Posted: Thu Dec 31, 2020 2:34 pm
by Bill Everett
Although I've never seen one, nor have I heard that these existed, my guess is that when in current production, there was a drawing of a finished engine block with all the machined areas' dimensions.

Does anyone know what the "when new, finished, and ready for assembly" did the block's intake and exshaust ports dimensions were?

Also, has anyone ever felt the need to "clean up" the area on these ports where the copper rings go? As you can see, mine are somewhat pitted.

A respected engine builder told me to not give it any thought, that the copper rings will negate the need for any machining.

Thanks for your help.

Bill Everett

Re: Dimensions Of These Ports?

Posted: Thu Dec 31, 2020 2:46 pm
by TWrenn
Bill, this is yet another reason why I really prefer this type of manifold "gasket".
They do a good job of "taking up" any imperfections. Bit pricey, but believe me, they're worth it!

Try 'em....you'll like 'em as advertisements say! Happy New Year.

https://snydersantiqueauto.com/ProductD ... t/manifold

Re: Dimensions Of These Ports?

Posted: Thu Dec 31, 2020 3:33 pm
by Dan McEachern
Just installed a set of these. Chamfering the edges of the outside diameter on both sides of the copper 1 piece gasket rings made installation easier as any variation in the distance between the ports on the block and the manifolds make it a bit difficult to get both aides to go together. It took the chamfers and a little tapping with a soft face hammer to get things started. We put a little Super Black RTV around the intakes just to make sure to get a good seal in the intake ports. To clarify, I'm not suggesting to chamfer the manifold bores or the ports in the block- just the sharp edges of the copper rings referred to in the link above to the Snyders website.

Re: Dimensions Of These Ports?

Posted: Thu Dec 31, 2020 4:13 pm
by Norman Kling
I have not had to do anything with the bores of the ports. The gaskets actually seal against the flat surface of the block. When doing machine work on the block such as re-boring or milling down the top of the block, you can also take off just enough from the manifold surface of the block to remove the pits. I use the steel inserts between the manifolds and the block with the copper rings between the flat surfaces. If the exhaust manifold is not straight, the rings will not fit. In that case the manifold needs to be straightened or replaced.I would not chamfer the ports because if the manifold is not lined up correctly it is almost impossible to get a good seal. It should be straightened or replaced.
Norm

Re: Dimensions Of These Ports?

Posted: Thu Dec 31, 2020 6:22 pm
by Allan
Dan's chamfer idea works well. The material from which the gaskets are formed is thick enough to be able to file a good chamfer to start the rings into their seats. It is not the thin copper used in the round gland rings. With severely pitted blocks/manifolds I use a product specified for exhaust sealing to help with the seal. It cures with heat. Here in Australia it is called Maniseal. It comes in a tube and is the consistency of thick toothpaste, so it stays where you put it.

Hope this helps.
Allan from down under.