Darock,


George Aldrich was one heck of an engine man, as you wrote.

The whole theory of tapered-bore break-in, being done at a rich, two-cycling setting has his copyright written all over it.
It is not my idea, nor that of anyone else in this forum.

But we do base what we write, on his notes.

I also base it on my own experience.


George Aldrich reached his conclusions when a tapered-bore engine was actually designed to last 100 hours; not 15 hours like some current "Nobody ABC" engines produced today (like the ones Brian experimented with...).

He actually saw these tight engines break their crankshafts, con-rods and wrist-pins and measurably wear away their piston's crown's fit in the top of the sleeve, by pounding the piston into the cold, tight bore top, during what was then considered to be the only right way to do the break-in; i.e. slobbery rich four-cycling.

I actually saw ABN engines that peeled their nickel as a result of the same and others, especially people with car engines, realized that with 'hobby-shop-and-engine-manufacturer recommended' slobbery break-in, their engines last for 3 gallons, before needing a new P+L set. And yet, they held up for 12-20 gallons, with the DarZeelon recommended, slightly rich break-in.

I believe that says it all, as well as saying some engine manufacturers and the hobby shops want to sell us a lot of expensive spare parts...