One more plug for George at : He's written a wonderful artical (About 80 pages long) called Lister Longevity. He suggests that folks buy it before they get into one of these engines, and I'd have to agree. Some manufactures do a better job than others, I think mine falls somewhere inbetween. (George knows which ones are good, which are bad.. and which are a good gamble!) "Lister Longevity" goes into a lot more depth than his pages at , and it not only tells the reader what they may be getting into, but it also details lots of assembly/disassembly proceedures - lots of tips on improving them.... the document in my opinion makes the engine a much more valuable thing.
There is a documented story of an automotive engineer showing up at a state fair booth where a guy was demonstrating an oil additive. they had a motor set up where two pieces of metal rubbed together and you could see the reduced friction when their product was added. The Engineer asked the guy running the booth if he would try 'his stuff', .... new pieces of metal were installed and this mystery concoction was added. To the amazement of the Booth Operator, he couldn't apply enough pressure to the disk to slow it down! The performance of this mystery stuff was off the chart, and clearly better than the stuff he was selling.