Author Topic: Exaust Valve for Plus engine  (Read 264 times)

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Offline douglas1947

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Exaust Valve for Plus engine
« on: 12 Oct 2022 at 07:05 »
Im still working on my 80 Plus engine. It has the standard Plus iron heads.
The exaust valve seats require a valve dia of minimal 34,0mm.
I have only valves of 32,3mm dia. when I use these, I have to cut too deep in the valve seats.

Has anyone an idea what valves of other engines I can use to make it fit to the Plus head?
I have already fitted new valve guides (11/32"  =  8,7mm bore) in the heads.

I will be happy about ideas and help.

Michael

Offline douglas1947

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Re: Exaust Valve for Plus engine
« Reply #1 on: 12 Oct 2022 at 07:28 »
SORRY!!!

I made a mistake! 

It is the inlet valve that will not fit!!!

Michael

Offline graeme

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Re: Exaust Valve for Plus engine
« Reply #2 on: 22 Nov 2022 at 05:47 »
Hello Michael

If you start with a valve that has bigger dimensions you can machine it to the size you require. I have done this for a couple of bikes I have worked on in the past

Cheers, Graeme

Offline douglas1947

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Re: Exaust Valve for Plus engine
« Reply #3 on: 22 Nov 2022 at 06:59 »
Hello Graeme,

thanks for your reply. Unfortenatly the stem dia of 11/32" is not very common. A lot of valves with that stem dia are used in US car engines, but with very bighead diameters.
I have bought 2 IHC tractor ex valves (IHC) and turned / grind the heads down to the size I need. I will use the valves for the inlets.
The valves are still a bit bulky and I think about to get the heads more graceful.

For the 80+ exaust I will usethe old inlet valves, because they are 1mm bigger in dia than the original ex valves. I think they are of the same steel to stand the heat.

Michael