Darn good question.
I just finished lapping all eight of my new valves after getting the head
back from the machine shop. The blueing was still on the valves and seats.
I have always lapped new valves after the shop grinds them. Have I been
screwing up all these years? Do newly ground valves and seats need lapping?
Glen
> Noticed in an engine book the other day the advice to fill the combustion
> chambers in the head with a solvent to see if your valves are sealing
> properly. No leakage into ports over night means all okay.
>
> I tried it with some kerosene on a head I recently rebuilt. Two chambers
> emptied into the intake ports over night. Since the intake valves and
seats
> were done on a NewWay cutter and the exhausts on a Sioux grinder, I
figured
> maybe they needed some lapping.
>
> Did the suction cup and grinding paste thing on all 4 intakes. Now all 4
> leaked over night!
>
> Should I use the head as-is or seek professional intervention? (I guess
> going to the list does approach "professional" in some cases).
>
> JohnD
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