At 09:50 AM 3/6/2012, Ken Wilford wrote:
>Here is a typical call, "My van idles funny."  I ask, "Did this start
>after you had some head work done?"  Customer thinks I am clairvoyant.
>I tell them to adjust the valves to zero lash and see if this helps.
>They email me a few days later saying the problem is gone and the van is
>running better than ever.  If you have a little clacking adjust it to
>half a turn preload and you should be good to go.

Which is another way of  saying that they should have used solid
lifters, or some kind of hydraulic that's meant to work on its
side.  'Cause the two-turn preload should simply be putting the
lifter into the middle of its operating range.

These lifters have been used since - I used to know because I did a
good deal of research for Boston Bob on this problem - ?the thirties?
and the two engines I know of where they have problems are both flat
fours.  The other's an aircraft engine, Continental IIRC.

My '84 would lose ~20# of compression if the lash wasn't set to
zero.  And that's starting with lifters that had been prefilled by
the book, or after the engine had run a few thousand miles on them,
either way, old engine or same engine freshly rebuilt.  Bob gave me
some of the spring-loaded pushrod tubes so I could take them out to look at.

Yours,
David

Yours,
David