What passenger cars are out there that will handle O27 curves? How about 15" or do they have to be shorter?
15 inch cars can handle O027 curves but look pretty silly doing so. You probably want to stick with cars that are around 12 inches long.
Williams makes O-27 streamlined passenger cars in various road names. The length coupler to coupler is 12". Classic postwar look with silhouettes in the windows and lit interiors. Nice cars…
MTH also has some short cars that are pretty nice that will work on 027 curves.
A car 12" long is about the same as your radius. 6 cars this length will fill a circle of O27 track while 3 will cover a semicircle. They may look a little weird bent like that.
The cars that look the best on 027 curves are the Lionel 027 streamliners and the Williams reproduction of this item. The previous K-Line 027 streamlined passenger cars are more nicely detailed and a little bit longer, but can rub against the housing on Lionel 027 switches.
The shorter Madison cars will negotiate the curve as will the newer Lionel updated streamlined passenger cars - also very similar to the older MTH Railking ones. But these cars are a little bit higher and wider, so it also depends on your taste and what other kinds of engines and rolling stock you run.
For the traditionally sized 027/0 types of cars and locos on tight 027 curves, I think the 11-inch older Lionel and the William’s counterparts look the best.
It is certainly possible to add extra details to these cars too. I’ve created my own unique window silhouettes using a graphic arts computer program and then glued them to blue tinted plastic. I also hand paint all the handrails and the molded in diaphrams at each end of the cars.
I’ve got some Williams 15" madison cars. They make it around O-27 curves but they look really odd. It’s like they pivot around the curves. They kind of jack knife through the curve. The shorter passenger cars as stated above are the way to go.
I started with Lionel 2400-type O27 streamliners. I have a dozen red-stripe Santa Fe cars; but I never run them and have about decided to try to sell them. They just look way too small behind a scale F3. On the other hand, I do run another dozen UPs, which look fine behind the Anniversary Alcos.
The rest are mostly larger and have scale or near-scale cross-sections; you might like some of them:
I have some Rail King 12.25-inch UP heavyweights which run without modification, although I removed one of the rather stiff pickups and loosened up the center bearings to get them to track better.
Lionel Madisons (mine are modern reissues) are a little longer, 14 inches, and run well on O27 without modification.
My Williams heavyweights are the same length; but I had to add a washer to each center bearing to get the body sills over the switch machines–no big deal.
The longest cars I run are MTH Superliners, at 15 inches. These I had to modify extensively, moving the center bearings inboard a couple of inches, to keep the middles of the cars clear of the switch machines.
The overhang of long cars on curves just doesn’t bother me. I guess it’s in the same category as being oblivious to the center rail.
These post war passenger cars are about the biggest I want to use on o-31, and I believe they are about the shortest out there.
That pretty much says it all there.