rebulding an engine is relatively not that hard. Its been about 13 years on my moms's Honda Accord (1986) A16A1 engine, I rebuilt it myself with a few freinds help using oversize pistons and crank bearings, rebuilt the Cyl head myself by hand - derusted the cooling jackets, cleaned out the oiling galleries etc. Rebuilt the whole A/C system too to factory specs
This engine has done 400,000 Kms after the rebuild (4 T belts water pumps and 4 clutches later) - it starts up on first crank everyday till today. All I have to input is there are some points to notice.
Coolant mixture flush every 2 years
Fresh engine oil and MANN filter every 5000 kms
fresh transmission oil every 2 years too
MANN branded air filter replaced every year
Engine is never pressure washed, always washed by hand.. Simple factors that can elongate a car's life by a few magnitudes