valve leak?

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sition

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Hi!
Have you ever encountered an engine valve leak?
My engine valve always leaks. It will leak after running in for a while. If the valve is lubricated, he will leak a little. 45 # steel was used for my valve and it was simply quenched. How can I solve this problem?
Thank you
 

Longboy

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Re-cut the valve and/ or seat. You can rotate the valve on its seat with a dye and see the area not in contact. I will be trying some 12L14 steel for valves in this year's project but have had no issues with plain ole CR on a brass seat.
 

coulsea

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valves can be tricky things but the principle is basic, the valve must seal on the seat. if you have a hard valve and a soft seat you simply lap the two together. Dye on the valve will show up any errors, if the valve is not as round and flat as it should be lapping will not help as the seat will wear a lot and the valve not much. a toolpost grinder or a d bit grinder will give a good finish to the valve which will then transfer to the seat through lapping.
 

Foketry

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I suggest you to leave the valve seat sharp, the lapping will create a small chamfer that will adapt to the valve, then check the leak through manual vacuum pump
 

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