When I retired, just over 7 years ago I decided to build engines, mainly A-series. I built several but got fed up with folk asking how 'cheaply' I could do them. In the end I gave up as owners wanted 'cheap', rather than properly built for reliability, long life & reasonable power.
It takes many hours to do a thorough built which includes at least one 'dummy build' followed by a strip down and final machining. The parts needed list is long and for top quality parts is not cheap.
In the end I gave up as even though I was only charging between £25 & £30 per hour, many seemed to think that around 35+ hours labour for a full and professional rebuild was too much.
Now I just build engines for my friends and for myself/family. Next engine will be a 125 bhp MGB unit for my Grandson's 1971 MGB-GT. To him my labour is free
and I can take as many hours as I wish.
If so-called 'engine builders' can do a top quality job for less hours, then I would be amazed.
Absolutely.
It takes what it takes. I don't do too many at all these days, like yourself, for family and friends that I have gotten to know well.
I have been asked how long it takes me to do one and my standard answer is I don't know.
I did just finish a complete Power Unit, Engine, Gearbox, Clutch, Carb, Dissy, Cooling System, Exhaust and then fitted it, got it running and did a few KMs in it. 9 days, spending about 7 hours a day (though we did have one short day), so about 60 hours. That was just for 'assembly and fitting' that didn't include disassembly, inspection and machining.
I don't know how many I've done now, but no 2 have been the same, there's always hurdles to overcome, some are easy, some you just can't predict. For example, on that last one I did, it took us around 2 hours to fit the fan. Yeap, 4 bolts, how hard could it be! Well, the holes were 6 mm to start with, then the blades were bent (6 blade metal fan, new BMH Item), then when fitted up with the radiator, it fouled the cowling, so we machined it back, then on the third trial fit on checking if a fan belt could be fitted, it couldn't and we had no spacers in either, so off to modify the Radiator Mounts,,,, it all takes time......