My understanding of RC car and truck engines is limited, but I believe most all of them are of the non-ringed ABC 2-stroke variety. With airplane engines, you'll find both ringed and non-ringed engines (ABC or ABN type) as well as 2-strokes and 4-strokes.

Airplane engines are mostly lower compression than car/truck engines and don't take much work to turn over. Certain brands of airplane engines can take a bit of work to start, however, until they get broken in completely and have been flown for a while.

The O.S. and Thunder Tiger engines that are offered with Hobbico and Thunder Tiger RTF packages are not difficult to get running. I've never operated an Evolution glow engine, but folks who have purchased them with their Hangar 9 RTF trainers usually report that they're easy to start.

The Tower Hobbies .46 ball-bearing engine that comes with the Tower Trainer .40 MkII RTF package can be difficult to get running at first. It's a good powerful engine, but they take a little extra work as far as breaking one in or getting it started before it's broken in.