AQad40 Cruise rpms

I have a 24 foot bayliner powered by a aqad40 with a duo prop on a volvo penta 280 outdrive. What is the cruise rpms supposed to be? I heard around 3200 or so but not really sure.

i normally cruise at 3000rpm 20knts

3200rpm max continuous cruise

seldoviaboater said:

I have a 24 foot bayliner powered by a aqad40 with a duo prop on a volvo penta 280 outdrive. What is the cruise rpms supposed to be? I heard around 3200 or so but not really sure.

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The max continuous cruise rpm for the AQAD40B (165 hp) is 200rpm below maximum permissible or 200 rpm below what you can get.
Max permissible loaded is 3600. Thus, if you have exactly the right props for your boat/engine combination, in good condition, with a clean hull and no excess weight on board and can achieve 3600, then your max cruise must be 3400. If you can only get 3300 then your max cruise is 3100, and so on. This is Volvo's recommendation.
If you have the AQAD40A or B, the turbocharger pressure measured at the inlet manifold should be 0.96 bar WOT (wide-open throttle) between 3000 and 3600 at an intake air temperature of +20 degrees C. Higher temperatures will decrease the inlet pressure and thus the power due to reduced air density.
Incidentally, if your injection pump is set up correctly, the rpm should govern to 4050 rpm in neutral. Only test this with a warmed up engine and the leg fully down!
I have 2 x AQAD40B in a Phantom 32 pulling A9 props on 280 legs, the boat is 6.5 tonnes prepared for service, (638 l fuel, 318 l water, 3-4 persons and normal personal gear) and with a clean hull & props I get 31kts at 3600 and 9.5 bar boost and cruise at 28kts with 3400 and 94ish boost but I had to modify the boat to get more cool air into the engine room to achieve that performance.
Best of luck!