Re: Timing tutorial?

Wayne Laepple Wrote:
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> No. 90 used to sound a lot worse. My recollection
> of it early in its Strasburg career was that it
> was not square at all. In fact, starting from a
> dead stop at Groff's Grove westbound, it sounded
> like a three-cylinder engine. A couple of years
> later, it was repaired, and I recall an
> explanation somewhere that involved its valve gear
> having been scrambled a bit by an errant motor
> vehicle while it was still in Colorado.

When they first set the valves on #90 in the 1970’s, they found that the left side (which had been on the receiving end of all the accidents) was much closer to square than the right side. Apparently post-accident valve setting only dealt with the side that was out of commission, leaving the right side to rot.

Russo Loco Wrote:
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> Russ's treadmill that makes rotating
> the eccentric crank to the exact position so much
> easier – what a GREAT idea!!
>
> Have you thought about using an eccentric bushing
> on the link end of the eccentric rod, Russ, or on
> the link itself – sorta like this?
>
> Since we're talking about only a few hundredths of
> an inch here,

Valve setting rollers were a standard tool in backshops across the country. You can spot them in the chapter on shops in the book The 1940's The Decade of the Trains, and in the ICS books on valve setting.

Russ is right, eccentric bushings are to be avoided. Also, while the precision you are hoping to achieve is within a few hundredths of an inch, the adjustment needed can be way more that the thickness of the bushing. We have had to adjust eccentric rods 3/8" already.

Russ489 Wrote:
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> We will eventually have to work on the links. As
> far as I know the link grinder in Durango is still
> functional. I am told it is one of the few
> machines that survived the fire. Another option
> is to have them machined on a CNC mill. We had
> the links on 401 done this way at Monticello and
> it worked very well.
>
> Russ

Here is the link grinder we built to work on our planer. It only got used on this one job before we got a CNC mill which we have been using ever since.