Keith,
1 You run at 2000rpm to go 8 knots?
2 “Nominal” meaning may not be accurate?
3 Do you know your engines aren’t overloaded at 9 knots?
4 Do you ever run WOT to test engine performance?
5 Don’t suspect your oil is running cool but have you tested it?
6 Or EGT ?
7 HaHa 3.5 knots in a marina sounds fast to me. I go in and out of gear. I shift quickly and I’m sure there’s no undo wear on the clutches .. BW gear.
8 What would be your top speed if you were propped to rated rpm? 10-11?
1 yes
2 yes
3 yes, no black smoke, but I can make black if I go faster.
4 no, not necessary. I had a catastrophic failure due to water intrusion a few yrs ago. When torn down, no glazing, no evidence of underloading or overloading, after 1500 hrs of the same routine, so I will continue the same routine.
5 temp guages show full operating temps at 7 knots. I don't know what speed would get to full operating temp, as I haven't cruised below 7.
6 don't have one.
7 lots of room in my marina, but I feel like I am going quite slow at 3.5. Also BW gears.
8 used to go to top speed, though with lower hp engines. Never saw 10.5, hull requires lots more hp, maybe double what I have to get out of the hole. Present engines only 33% more so not nearly enough to go much faster. Going up to WOT? Won't go fast, might hurt the engines, costs in dramatically increased fuel usage, no benefit, so I never do it.