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Valve grinding with hardened seats ?

Posted: Tue Jul 01, 2025 6:34 pm
by Joeck
I have been grinding in a new set of valves into hardened valve seats .
I can get a nice grey ring around the middle of the sealing face on the exhaust valves but get a narrower grey band near the top of the sealing face on the inlets.
I have filled the combustion chambers with white spirit and there is no leakage overnight.
Is the narrow grey band on the inlets sufficient or do I need to carry out further work?
Thanks
Joe.

Re: Valve grinding with hardened seats ?

Posted: Tue Jul 01, 2025 7:04 pm
by philthehill
I can sympathise with you - It is difficult to grind in valves that mate with hardened valve seats.
I think that you have reached a good position in that the valve seats do not leak past.
It is important to get a relatively wide seating on the exhaust valve so that valve heat can be transferred to the head.
The width of the inlet valve seat is less important as all you want there is a seal. The incoming charge cools the valve and seat.
Personally I would not spend much more time if at all grinding those seats.
Good luck.

Re: Valve grinding with hardened seats ?

Posted: Wed Jul 02, 2025 2:53 pm
by Joeck
Thanks for the reassurance.
The exhaust valves do have a nice broad-ish band and, although the inlet seating is towards the top of the valve seat, it is a smaller yet reasonable width.
As you say there is a lot of hard work involved in getting to this stage.
Thanks again.
Joe.