The last engine that
I rebuit under the shade tree cost between $2500 and $3000. It was a '91 Mazda MPV 4 cylinder - 3 valve/cyl engine (look at the price of parts for one of these babies some day). I removed the engine in the shade and took the block and head to a guy that builds dragster engines. He bored it and installed the new oversize pistons/rings and machined the head, replaced timing chain/sprockets. I don't remember if the the valves were replaced or not. The wife had run the engine hot and "scarred" the cylinder walls and screwed up the rings. It was done over a period of about 4 or 5 weeks.