2. Scrape off all traces of the old gasket material from the mating surface of the block. Try not to leave any burrs.
3. Remove all covers and threaded plugs of oil galleries from the block. The plugs are usually tightened very tightly, so it is quite possible that they will have to be drilled out and then the thread in the hole restored. When assembling the block, the plugs should be replaced with new ones.
4. If the engine is heavily externally contaminated, it should be taken to a car service workshop for steam cleaning or heat treatment.
5. After returning the block from the workshop, thoroughly clean all oil holes and galleries again - special cylindrical brushes of a special shape are produced for this purpose (ask in car accessory stores). Rinse the cavities and channels with warm water - continue rinsing until clean water begins to flow out from the opposite side of the block. Dry the block thoroughly, then lightly lubricate all machined surfaces with liquid oil to protect them from corrosion. If you have access to a source of compressed air, use it to speed up the drying process of the block and blow out hard-to-reach cavities and channels.
Attention! When working with compressed air, do not forget to wear protective glasses!
6. If the block is heavily soiled or slagged, use a brush cleaning with hot water and soap. Do not try to save time by neglecting the cleaning of the block. Regardless of the method chosen, make sure that hard-to-reach cavities, channels and holes are thoroughly cleaned. Finally, dry the block and lubricate the machined surfaces with liquid oil to protect them from corrosion.
7. Run a tap of the appropriate size through all the threaded holes in the block to ensure that the torque wrench indicator readings correspond to the actual tightening forces developed when assembling the engine. If possible, then blow out the run holes with compressed air, removing all small debris and chips from them. After finishing the holes, run a tap along the threaded part of the bolts.
8. Install the main bearing caps in place, hand tightening their fasteners.
9. Lubricate the threads of the new plugs with non-hardening sealant and seal the holes in the oil galleries with them. Make sure the plugs are tightened securely.
10. If you are not going to start assembling the engine immediately, place the block in a large plastic bag to protect it from contamination.
[The article was taken from the website www.HondaBook.ru]