Ad0911

Why is this engine so hard to turn over by hand? I replaced rings and rod bearings and oiled everything generously when installing. Heads are not on yet. Turning the crankshaft by hand using the flywheel is hard. But my comparison is an old beetle. Apples and pears?

Wisconsin Joe

More like "Apples & Bunny Rabbits."

More pistons, more friction.
Water cooled has much tighter tolerances than air cooled. More friction.

dr bob

Part of lower-end assembly includes rolling the crankshaft a couple revolutions after each new item is connected. Crank in new bearings, then girdle snug, again when girdle tight, then as each piston and connecting rod assembly is attached and torqued. You should be able to identify the varying drag/loads as you attach more things. Most important, you can identify early any interferences that otherwise cause weeping and gnashing of teeth later. I've built "interesting" engines easily a dozen times in a few days, chasing fugitive rubs and binds during assembly. I'm regularly amused by the hot-rod TV shows that have an engine assembled from a benchfull of parts in a half-hour show. That's never happened in my workshop; there's always something that isn't quite perfect, and needs more attention.