Over many years I have worked on bug, BMW and volvo engines. Each one I
repeated at least one more time and yet the job wasn't as successful as
I liked. The only satisfactory rebuild was the very first time of a bug
engine DONE BY MY MECHANICS!!! Sad sad sad!!!

After so many unsuccessful effort, I learned a simple lesson. Replace
parts that need to be replaced and pay $$$$. Or the effort (of saving $$$$)
could be wasted.

The biggest $$$$ item is the cylinder heads. People tend to try to salvage
them by rebuilding them. More likely they either fail to perform as you wished
or do not last long. The cylinder liner set (cylinders and pistons/rings) is
an item must be replaced. It is not cheap (except bug engines) but worth the
cost. If you can afford it, replacing cam/rocker/lifter completely to get up
to another 10 years of engine life is possible. Get a new oil pump or make
sure yours is reconditioned to get maximum pressure. 

My mechanics has a fairly good reputation of rebuilding engines. His secret is
get everything replaced. You pay more and get a satisfactory rebuild.

Flames (not to me) please as this is an interesting subject.

David Kao