ORIGINAL: blw
ORIGINAL: jaka
Hi!
First of all you must remember that no modern ABN, ABC, or AAC engine really need running in!
''Running in'' with these engines mearly means getting aguainted to the high and low speed needles.
But you might think of older (40 years or more) ringed engines...?
Modern Saito AAC engines are ringed and need a break in period. Click here to read the manual and learn how it's done:
http://www.horizonhobby.com/ProdInfo..._manual-lo.pdf
No engine is exempt from running-in, all machined parts to wear out together to get the perfect fit. Thus, no machine tools can do better. The principle for the machining of metals is the same as for more hundred years ago, only the accuracy is improved in our days machining tools. But the surface is not free of tool marks before the parts are adapted by running-in together for perfect fit.
We have chosen other materials than we used cast iron/steel as piston/cylinder material and we get shortened running-in time in modern model engines.