Is a valve plate viable?

[lee websterParticipant @leewebster72680]

I thought I had better get acquainted with valve cages when I started to draw a small engine in Solidedge. I watched a video by Andrew Whale on the tube. The design was similar to how I thought it would be. But I also wondered if a steel plate with the valve seats could be fixed into an aluminium head.

The silver part is the steel plate, one in place in the head, and one outside to show the shape. I drew the plate at 5mm thick, but I'm sure it could be thinner. The plate is held in place with two bolts/screws with sealant between head and plate.

The cutaway pic shows how the plate would sit in a machined recess in the head.

Is this viable? I feel that I have seen something like it somewhere.

[lee websterParticipant @leewebster72680]

[noel shelleyParticipant @noelshelley55608]

Commercially it's done all the time, so yes. Sealing might be the only problem normally cast in or press fit then machine the valve seat. I would use 2 seperate seats. Noel.

[Dave SParticipant @daves59043]

For an alloy head and steel insert a shrink fit would be ok imo.
heat head, freeze insert get stuck halfway in and learn some new curses

Dave

[lee websterParticipant @leewebster72680]

I have seen videos about valve seat inserts. They seem to involve heat and extreme cold. I thought a single plate would be a lot easier.

[old martParticipant @oldmart]

It might be easier to shrink fit and seal if it were circular, fitting into the bore of the head. Even better sealing if the outer diameter sealed with a head gasket. Normal practice is to make two circular cast iron seats which are shrink/press fitted into counterbored holes in the head and then the seats are finished in line with the valve guides.

Edited By old mart on 25/07/2023 19:20:44

[old martParticipant @oldmart]

I forgot to add, if two round seats are close together, the counterbores may be better overlapping and the seat inserts with flats where they contact.

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