Precision Scale from the late 80s and early 90s running quality

I have two PSC models from the 80's era. An N&W Class A 2-6-6-4 that I was told when I bought it would fall apart and need to be reworked. I also have an N&W Class S1a 0-8-0. The S1a has been a smooth runner and is fine. The N&W A sounds like a coffee grinder but it has surprisingly run reliably for 10 years or so. I also have a more recent Z1a and Z1b which have run like a champs. Knocking pretty hard on wood regarding all of these.

Maybe the way you should look at this is: How bad do you want this locomotive/these locomotives? Are there any alternatives out there not made by PSC? Do you want it bad enough that you would be willing to do a re-power if it croaks?

Simon

I had a PSC AC-6SF for a while.  It was dead-smooth in operation, but far too detailed for my tastes.  Traded it for some USH.

Thanks for the advice from everyone.  It is appreciated.

I'm considering a PSC PRR K4 Pacific.    Does anyone have any thoughts on their running qualities?    I have a painted and unpainted USH K4.    I am thinking of replacing the unpainted one with a "modernized" one from PSC that I know about.

You will like the boiler contour better on the PSC.  USH copied the MRR Cyclopedia.  Max Gray did it correctly.

I have several PSC K4's (and a scratch built PRR K5 with a modified PSC K4 mech).  Out of the box I was not pleased with the PSC K4's performance. They were weakly powered by small Pittman 8412E702 9.5v can motor. The motor sits horizontally in the firebox on a shelf like fixture bolted to the frame.  A plastic hex nut coupling connects the motor to a spur gear tower, which in turn is bolted to a PSC 25:1 gearbox.  To pull 8 chart passenger trains unassisted around my representation of Horseshoe Curve  more weight in the boiler would be required to reduce driver slip, and a higher torque motor would be needed for smooth low speed starts.  My solution was to junk the motor and spur gear tower - and drive the 25:1 gearbox with a hefty Pittman 9233 motor.  I made a new motor mount and coupling setup (options include NWSL dog bones, tubing, or the hex nut collar). The 9233 does barely fit in PSC's 1:48 scale dimensioned K4 boiler.  The revised drive setup has worked well for me  for around 30 years.

Opinion follows:  if you are a PRR rivet counter don't stand the PSC K4s next to a USH KTM one.  They look like two different locomotive classes given the over scale dimensions and proportional errors on the KTM model.    The PSC model designed years later benefited from interested modelers having access to PRR engineering drawings preserved by the PRRT&HS.   On the plus side USH K4's look nice and were solidly built models.