The information you posted provided descriptions of different running modes, not suggestions on how the engines should be run. The descriptions you posted preface the section on breakin and running:

AIRBORNE BREAK-IN

1> BREAK-IN running should be done with the recommended propeller at a slightly rich setting. You want the engine to be at running operating temperatures. The needle valve should be set at a point just into this range from a four cycle setting. Fly the plane at maximum throttle for 2 minutes, then throttle back to half throttle for approximately 30 seconds. Repeat this sequence until approximately 20 minutes of accumulated running time has been obtained. Additionally, certain maneuvers, such as "CUBAN EIGHT'S", that allow the engine to load and unload are recommended. AVOID PROLONGED CLIMBING MANEUVERS AT MAXIMUM THROTTLE.

2> After the first 20 minutes change to normal size prop and fly an additional 15 minutes. Continue to run the engine at a slightly rich setting and fly your normal pattern.

3> After the above break-in period, run the engine at a normal peak needle valve setting. This should be a little on the rich side because engines run leaner in the air. 5% - 15% nitro may be used.

I would hope that any person running one of these engines for the first time would take a couple minutes and read the instructions, all the way through. I know I do this. However, I've also worked in customer support for years. I know that no matter how well written, or short, a manual is, many people don't bother to read it. Others will read it and get hung up on little inconsistancies and miss the big picture, such as step 3. We get so tired of telling customers something that's in the book that we developed an acronym for it, RTFM (bet you can guess what the F stands for), the PG version is below (blank lines inserted to create suspense, scroll down by line instead of by page):
READ


THE


F...










...ine


Manual

16.2 is perfect for a 424 setup. Nothing wrong with that

my Thunder Tiger .40 engines get up OVER 16.5K on the third run (clipped prop) and by the 5th tank hold at least 16K with the 9x6.

Right outta the box I run TT PRO .46 engines at 16.5K with a 9x6 prop for 2 minutes. Then it is an 11x5 prop for three 8 oz tankfuls 2-3 clicks off of full lean at full throttle. It is almost broke-in and ready for a plane then. After about 10-15 flights I do the final adjustments on the idle and top end then I RARELY have to touch the settings again. That is a "Textbook ABC/N George Aldrich" break-in. Those engines just keep getting better until you have MANY gallons of fuel through them. To do otherwise with an ABC/N engine is foolish IMO.

...to each his own...you bought it...treat it how you want to...it'll be your problem, not mine.

Dar, you're playing with semantics to confuse the issue. Take the head off your car and look at the bores. Do they still have the cross hatching they had from new or are the bores polished? If polished, have you mistreated your engine?

Yesterday I finished running in the engine as per Dar's thread and last night I stripped the engine and spent some considerable time checking everything closely and taking some photos. There was one thing I found that caught me by surprise but I'm considering starting a new thread with two posts...the first for the rich running and the second for the "proper" running in.

Brian,


Most car engines, that have a cast iron cylinder block, or sleeves, will also have cast iron compression rings.
With the rings properly gapped, the wear on the sleeve's crosshatch pattern will be visible, but with the crosshatch made pretty deep, like with a Sunnen K machine, it will still be visible.

If this engine has the top ring chromium plated, the wear of the crosshatch may be more extensive.
With a molybdenum coated top ring, no wear will be visible on the crosshatch.

With a chromed sleeve, the crosshatch will be like new even after many thousands of kilometers have been accumulated.

With an ABC engine, I think this is the closest combination.
The high silicon aluminium (hyper-eutectic) piston is very hard, but it is still softer than the chromium on the sleeve.

I would expect, in a modern ABC engine, with the top 1-1.5 mm of the piston relieved, no measurable wear, but the piston more shiny just below the recessed portion (0.1-0.3 mm), following break-in. I would expect no visible wear on the sleeve.

In MVVS engines, which I deal with now, there is no crosshatch. The sleeve is just lightly sanded after machining is completed. So seeing wear in the crosshatch pattern is obviously not possible...