So, essentially, the K-27 will make it around 8' dia. curves but will not double-head because the front coupler swings WAY too wide! Okay, that's nothing new as we have had the same thing with the Connie! It's front end also swings too wide on 8' dia. curves to double-head but it does navigate them as a single engine. It will be interesting to see what the minimum diameter curve is that would be needed for double-heading.
The instructions also mention that you can widen the slot in the plow and use a longer shank coupler (provided) to (probably) allow double-heading on very tight radius curves. I think 5' radius without problem. We had two double-heading on 6' radius yesterday and there was quite a bit of margin.
The loco comes with quite a few extra couplers that have verious length shanks.
I have been running my K-27 around Aristocraft 10' diameter curves with out any trouble. This is the only curve track I have, other than switches. My switches are LGB 18000 series. Those are 17' diameter.
This afternoon I tried doubleheading with a Connie. The pair went around the 10' diameter curves without any problem.
I am using Kadee 830s on the Connie pilot and on the K-27 tender.
Does anyone know how much the cab will swing out on minimum(4' radius, 8' diameter) LGB curved track? I'm running my railroad in a 12x20 foot barn, and the Connie is a bit of a stretch on one bridge that I can't move(built in). Much more rear overhang/swing than the Connie will almost doom me to never have a K-27.