Our Albin Ballad came with the original (1972) Volvo engine. It runs, tho it can be hard to start in the cold and smokes a bit. We have not yet given it our full attention, but here are its known issues:
1. It is only 10hp for an 8000# boat; bulky and heavy for that much output.
2. Raw water cooled (Great Lakes boat, tho).
3. Jacketed exhaust, not water-lift.
4. Has both an alternator and the curious belted starter/magneto generator.
5. Very short distance between transmission and shaft seal.
6. May have an external crack in block; looks like a JB Weld repair. If so, it's on the cool side.
7. Rear mounts are shot.
I haven't got round to a compression test or oil analysis yet. A final decision may need to wait for those results. But broadly speaking....
We imagine a few different strategies. We could just clean it up, maybe swap in new injectors, and run it into the ground -- as is. Raw water cooling in the Sea of Cortez puts a limit on its life span, but we can probably see the end from here anyhow. Let entropy have its due; repower when the axe falls.
We could strap on a fresh-water cooling system with heat exchanger and wet exhaust. Would cost ~$1000 for both. May extend the life of the engine until something internal fails.
We could fully rebuild this engine, add another decade or so to its life. Cooling and exhaust revamp, as well. Old Volvos never die
-- they just bleed you from a thousand cuts.
We could buy a reman, bit more HP; probably cost ~$4000. We'd do the work here, ourselves. Time is not an issue, tho the sheer cost of a repower would likely push our launch date back a year or two.
So do we tidy up the engine, focus on the other parts of the refit, and drive it til it drops? Do we sink some serious money into upgrading this old Volvo & hope it lives long enuf to pay off? Or should we grit our teeth and swap it now?
(The one thing about this engine that gives me the serious willies is that starter/generator. Dynastart, I think they called it. Is it an asset? A liability? Mostly it has 'nightmare' written all over it, but... There's something to be said for redundant battery charging. And even if it craps out, this engine can be crank-started manually.)