Several years ago, after Dave Hottman’s excellent thread elsewhere detailing the process of reversing the eccentrics of a Ruby (and his subsequent email to me on applying the process to the Shay) I made a stab at doing so.
Over the past couple years I was pleased with the results compared to how it ran beforehand. However since then I have been struggling with run times, excessive oil and water consumption, a leaky clack valve, a intermittent pump, incorrectly assembled trucks and a leaking steam valve. All those problems were present in the factory product. The reversing made it run smoother but did nothing for the other issues.
I attempted to deal with those issues so I would run the Shay more. I started a couple years so ago messing with a trail car and a propane cylinder for additional run times. Didn’t solve the oil and water consumption but made longer runs possible with the usual frequent pit stops.
This Spring I resolved to get it done. I found a Bernzo-matic mini torch and the associated smaller spray paint sized cans of propane at Walmart. The valve looked to be fine enough for adjusting fuel flow for the Shay so I bought it. Disassembled it looked like it would do the trick. I pulled the stock butane tank out of the cab and temporarily plumbed in a feed line form the new valve. I stole the O-ring from the gas valve and replaced the steam valves O-ring with it. Much snugger fit and no more steam loss there.
I then did Dave’s mod to the lubricator and fitted 3 then 4 nuts to the 2-56 bolt. Test runs showed much reduced oil consumption and less oil popping. By the way…how much oil consumption is actually needed?
I ripped out the tender pump and again disassembled the clack valve. Even fitting a heavier spring did not alleviate the leaking so its needing replacement.
I had a heck of a time maintaining boiler pressure at 20 psi when running. I knew the leaking valve wasn’t helping but the leak wasn’t THAT bad! I started wondering about my tuning … It ran better than when tuned the other way but I had trouble recognizing the events with the overlap involved. When I had done the tuning I thought about how to eliminate the other cylinders effects. I thought that by removing the other connecting rods and using just one cylinder at a time I could do a better job of it. Trouble was…I was scared to death to take a stab at it!! So I did the best I could and let it go.
Having gotten braver…but maybe not smarter, yesterday I dove in. I removed the connecting rod from two the cylinders and tuned each cylinder on its own. I was amazed at how far off my tuning was given how much better the loco ran. I tweaked both the valve adjustment as well as the eccentric position until I got the easiest rollover. None of the cylinders would operate the crankshaft continuously. I had two that would turn it about 1 1/2 turns then hang. I tuned and tuned but got no better. I left them at the point where the lights touch would start it again. The third cylinder, the rear, would not do as well but was adjusted to the same point where the slightest touch would turn it.
If you have not disassembled these cylinders before its a bit daunting. However its straight forward and just require a reverse process assembling the parts in their original positions.
I found when I started this task that several of the cylinder head bolts were a bit loose and there was some leakage past them. Same went for the cylinder sections themselves as well as the crankshaft bearing caps. I tightened all but the bolts holding the cylinder sections together as I didn’t have a wrench or driver small enough to remove the shield over the cylinders. When I locate one I will go after them also.
End result was quite a surprise. Previously the steam valve’s minimum setting had to be 1/8 out to get the Shay to move. That was on straight level track at 20 + PSI. Max speed seemed to be at about 1/4 throttle. Any further open did not seem to make any additional speed increase. Steam pressure dropped rapidly when the throttle was opened and would not get over 20 PSI when the Shay was on the move.
Now…minimum throttle to get the Shay to go?..Just crack it the smallest bit! Max is still 1/4 turn but the water consumption decrease is ASTOUNDING!! At the lowest setting or a bit above the Shay runs for FAR longer than I have ever had it run before. Keeping steam pressure up was no problem. I regularly popped the pressure release valve as I learned the lesser fuel requirements it needed. The clack valve leaked about the same as before so I am confident the tuning was the major problem. Even adding water to the boiler, which used to stop the loco for a short time, didn’t seem to faze it now. I regret to say I did not time it as it was 0130 when I finished and other than the elation at how well it went I was dog tired.
My guess is that Norm Saley and those other experts discovered this far before I did. Its a bit of a task, taking me about 8 hrs to do, but it was so worth it!
Andre’
