ORIGINAL: 1QwkSport2.5r
You do realize that an ABC engine needs to turn at its peak/intended rpm to break in properly, right? A 10x7 prop will load a car engine way too much. It wouldn't turn more than 10,000rpm on that prop if even that. A .46 has a hard time turning faster than 13k on a 10x7. Not to mention you'd need to up the oil content of your fuel to run a prop that big.
Car engines don't spend much time at 40k, that's why they don't incinerate themselves on that break-in stand. They're only at WOT for a second at a time.
But hey, I'm an idiot.
That bench was designed to be gear drive so you could reduce the speed of the propeller while still achieving full rpm capabilities quite easily. It also has the clutch engagement so when your at idle the blade comes to a stop, it's also set up so all your adjustments are done behind the blade for safety. By changing the spur and clutch bell along with all the options of props available you can custom set the gearing and prop pitch to load the engine to whatever you like, from .12's to .36's.
As for heat cycling, I think it's a marketing ploy from the manufacturer so they can sell a whole lot of extra pull starters, one way bearings etc. It's as simple as when you are breaking in an engine, if you took it apart mid run and looked at the piston it would have a coating of oil on it. So if the piston isn't getting hot enough to cook/burn the oil, how is it anywhere near the temperature required to change the molecular structure of the aluminum? it simply can't and doesn't, so "imo" it is a waste of time. Start it and feed it fuel for as long as you can for the break-in and save all the wear and tear on the starting components. Also (and I can't stress this enough) use a HOT plug during break-in, the engine will start and idle so much better compared to the cold plugs that often come in the rtr engines.