I am having my heads rebuilt . Did porsche fit valve stem seals as standard on the 912 engine.
David
912 valve stem seals
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Re: 912 valve stem seals
They did and I think PRS told me not to bother with them on my SC.
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Re: 912 valve stem seals
Thanks
Max at revival thought it was just to the intake valves.
David
Max at revival thought it was just to the intake valves.
David
Re: 912 valve stem seals
Andy Prill from memory didn't fit them as the tollerance on the heads he refurbed for me didn't need them..
now this was some years back and I can't 100% recall if it's intake only or exhause only but I feel confident that with refurbed heads from him.. they where not used anymore. Call Andy or Graham Ex Rogers Bray guy.
now this was some years back and I can't 100% recall if it's intake only or exhause only but I feel confident that with refurbed heads from him.. they where not used anymore. Call Andy or Graham Ex Rogers Bray guy.
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Re: 912 valve stem seals
I might be wrong, but I've never seen valve stem seals fitted to exhaust valves. If you think about it, there's no point. There is always positive pressure in the exhaust tract compared to the rocker box, and that would mean that oil never gets down the exhaust valve guide.
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'91 Ducati 750/900ss mongrel
1963 Velocette Viper (mostly) with '39 KSS OHC engine
'05 997 C2
1954 FB Mondial 200 Extra Lusso
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Re: 912 valve stem seals
Can you explain what you mean? I thought the pressure was in both direction in the exhaust during different parts of the 4 strokeKneeslider wrote:I might be wrong, but I've never seen valve stem seals fitted to exhaust valves. If you think about it, there's no point. There is always positive pressure in the exhaust tract compared to the rocker box, and that would mean that oil never gets down the exhaust valve guide.
PS The folks on the registry agree with you
http://forum.porsche356registry.org/vie ... st#p187821
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