When I met Alan Lightcap some thirty plus years ago, he was
experimenting with a flow meter for setting up Ampico A secondary
valves.  I think the Ampico factory used this method for setting valve
travel.  I'm sure some MMD reader will know whether this is so or not.

Anyway, I also set up a system using air flow for setting the valve
travel in Ampico A's.  It turned out to be a more difficult process
than setting them up using a dial indicator.  The dial indicator showed
variations in valve travel after using the air flow meter.  The pianos
responded no differently due to the fact that I set the valve travel
lower than the factory settings.  Ampico A secondary valves were set
at the factory to travel 40 to 45 thousandths of an inch.  I have
always set mine at 35 to 37 thousandths.  I ended up using a dial
indicator after trying out the flow meter on a several Ampicos.

To address the point of valve travel: I do believe the few thousandths
makes a difference in the restoration.  If you log onto my web site
I have devoted several pages of the site to help collectors restore
their own Ampico A's.  Opening the following page:

  http://antiquemechanicalrestorations.com/4_Unit_Valves.html 

and following down to section B 20, I have illustrated the vacuum loss
of a valve as it is activated.  Lessening the valve travel in the case
of an Ampico A may not improve its performance upon completion of the
restoration.  However, when the restoration begins to age and leaks
develop over time, the efficient use of vacuum will extend the life of
the restoration.  That is to say, the piano will give a fine performance
for a longer period of time.  This holds true for reproducing pianos,
coin operated pianos and foot pumped players as well.

Although 37 thousandths valve travel is a good rule to follow, there
are some mechanisms, such as the Simplex, which were set with less
travel because they were designed to operate on higher levels of
vacuum.

Paul Manganaro

 [ Being a single-valve system, consistent air flow in the Ampico B
 [ was deemed essential.  On page 35 of the Ampico B Service Manual
 [ of 1929: "The amount of valve travel between its seats is very
 [ accurately adjusted so that all valves pass the same amount of air.
 [ To obtain this accuracy, the top seat is pressed into the correct
 [ position by a specially designed automatic machine, the operation of
 [ which is controlled by the amount of air flowing through the valve."
 [ -- Robbie