Originally Posted by capttb
The forty year old Tartan in the dock next to me has been doing quite well with it's original Atomic, owner likes to do the oil etc. every 50 hrs. or so.
I've done 150 mile or so near-zero-wind motorsails with the Atomic 4 and have no qualms about it. You will notice the oil pressure gradually dropping from the nominal 50 PSI to about 25 after 10 hours or so, but this is to be expected as the engine warms to its ideal temp (I have the freshwater T-stat and that temp is 175-185 F). Once I gave the oil pressure adjustment nut a quarter turn to get the pressure up to 40 PSI, but that was it.
I change the oil out every 50 hours too and had the oil pan tapped and spigoted for this purpose.
You'll find range is an issue. I get about 85 NM of range at 5 knots in flat seas, and usually carry five gallons in small jerrycans that I fill underway (conditions permitting). The advice about the blower is excellent: We find that if we don't keep the blower going in a following wind, the dorade vents in the lazarette allow some fumes (not enough to set off the CO detector, mind) back up into the cabin.
Essentially, though, we sail whenever possible and avoid situations where we HAVE to be somewhere and need the A4 to push us there. We have found that our fondness for "late season" cruising (mid-October) has meant more motor use in dying winds just to get to a moor before full dark, because mid-October means 11 hours of daylight here. But beyond that, the A4 itself is reliable and is a better choice than diesel for the "motor out of basin, motor head-to-wind, raise sail, shut off engine" type of sailing we prefer. Diesels want to stay on and age prematurely when run for short (under 1 hour under load) periods. The A4 doesn't care, being such a low-compression engine.