ORIGINAL: downunder
ORIGINAL: piper_chuck
Other than sticking to tradition (engines must be broken in sloppy rich) what's the goal?
A fair question but one which I thought I'd covered in my first post. I wanted to find out for myself what happens if an ABC is "abused" in this way rather than just following the sheep.
That's nice, but when "following the sheep" works, and is recommended by many experts, perhaps it's not such a bad thing.
I'm not exactly unfamiliar with engines so the hot and lean, rev the guts method of breaking in never seemed right to me (as in being the ONLY way to do it).
Perhaps the reason it didn't seem right is because it ISN'T RIGHT. NOBODY says ABC engines should be broken in "hot and lean". Everything I've read talks about running them rich, but not sloppy rich.
Nor did the oh so familiar cry that even a short rich run on a new ABC would cause irreparable damage. I like to experiment within the limits of what I think is safe.
Unfortunately, posting the experiment may lead less experienced people to ignore the directions that came with their engines. It would be unfortunate if someone reads this thread, decides to do things the old way (sloppy rich), and proves the experts right.
I won't experiment with using 10% oil but I will (and have) experimented with adding water to fuel to find the limits.
I hope you don't. The 10% oil comment was directed at Jan. He's elected himself as the spokesperson for the entire Europe while trying to convince those of us in the US that we're fools for using castor oil and running more than 15% oil.
So I'm simply experimenting to find out something for myself, I don't expect anyone to change their own methods of running in an ABC. As for whether my particular engine is "loose" or not...define "loose". That comment prompted me to check something a little more accurately though. I mounted a degree wheel in front of the prop and with the plug out I turned the prop until I could feel the piston bind in the taper. It bound up at 45 degrees BTDC (and this is after 18 minutes of sloppy rich running) so this is one thing I'll continue to check after further runs because it'll be a very good indication of whether or not the piston is wearing excessively.
I'm in the middle of breaking in an old, but never before run, K&B 3.5 cc ABC engine. I've never encountered an engine as tight as this is. Fortunately, it's going to be worth it. I've only put about 6 tanks through it, but it's already screaming, even though it's still being run rich (but not sloppily so).