Webster Valve after and before lapping taken from pcb microscope.

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chandrakumar

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This is picture i took from pcb microscope, just for fun. I learn that smaller seat as mention by "W5CYF / TinkerJohn" on his Upshur youtube video series really makes big different, i get better compression.
The valve is made from two piece , solder with silver soldering. this is a very quick way of making valve. The brass rod i bought from hobby shop 3mm, perfect size. The valve and valve seat , i used 12L14.
I need to know if 12L14 can be used for valve/valve seat ? I notice it get rust very quickly , not sure it will cause sealing issue in future, need some advice from community.
Valve After Lapping.jpg
another seat valve before lapping.jpg
another valve before lapping.jpg
Seat Valve After Lapping.jpg
 

Mechanicboy

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Use stainless steel when you are making the poppet valve and the valve seat of bronce. The exhaust gas has acids to rusting the steel parts on these poppet valves/seats.

I has Webster engine and still in good condition since 2008. :)
 

Nerd1000

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Thanks for the advice , Mechanicboy. I will find free cutting stainless steel.
You should be able to get grade 303 free cutting stainless. Keep in mind it is much less corrosion resistant than conventional grade 304.

That being said, don't throw away your 12L14 valves. They would be fine for the inlet, it doesn't see the same amount of heat and corrosive gases as the exhaust. In practice I think they would even be ok for the exhaust valve, the webster doesn't generate enough heat to damage carbon steel, and you'll likely only run it a free minutes every year.
 

chandrakumar

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You should be able to get grade 303 free cutting stainless. Keep in mind it is much less corrosion resistant than conventional grade 304.

That being said, don't throw away your 12L14 valves. They would be fine for the inlet, it doesn't see the same amount of heat and corrosive gases as the exhaust. In practice I think they would even be ok for the exhaust valve, the webster doesn't generate enough heat to damage carbon steel, and you'll likely only run it a free minutes every year.
Thanks for the info, I will try get 303. 0ne more doubt, can 12L14 treat with oil for blackning?
 

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