cruising rpm

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Scurvy Dog
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Vessel Info: 1987 Carver Voyager- twin 230 hp gas
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cruising rpm

Post by Crowbar »

twin 305's, 230 hp on 28' voyager. What is a good cruising rpm? Engines have 1550 hrs.
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throwback2
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Re: cruising rpm

Post by throwback2 »

I have the same boat with twin 230 Mercruisers and usually cruise at 3200-3400 rpm at 22-24 mph.Engines currently have 400 hours.
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hausherrs
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Re: cruising rpm

Post by hausherrs »

I have heard most people stick around 3200-3400 with all the v8. I have the 454 and I cruise between 3200 and 3400 which is about 20-22 mph. Anything less than 3000 and I feel like its struggling to stay on a plane.
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Scurvy Dog
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Re: cruising rpm

Post by Crowbar »

Thanks for the info. While I'm at it, what engine temps & oil pressure @ criuse do you see?
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MakinTime
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Re: cruising rpm

Post by MakinTime »

We have a 36 Carver aft with 454's. We go slow most of the time between 1500-2000 rpms (to be easy on equipment) @ around 10 mph. Sometimes cruise at around 3400 rpm and 23 mph not to often though.Our temps stick around 160 no matter how hard I am running them. Oil is around 60 psi.
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hausherrs
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Re: cruising rpm

Post by hausherrs »

Port temps stick at 160 and stbd 168. Closed cooling.
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feeez
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Re: cruising rpm

Post by feeez »

We have two "sweet spots" in our 350 mariner with 350MPI's.
When want or need to go along at a trawler like speed 2000 RPM will push us along at 8 to 8.5 knots and the boat seems very happy there. The other nice one for this boat is 3000 with a fair amount of trim tab engaged. This will give us 14 to 14.5 knots and a very comfortable ride depending on the conditions. Both of these rates give us very similar fuel mileage.

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tomschauer
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Re: cruising rpm

Post by tomschauer »

my 355 with mercury 454's likes to cruise at 3400rpm @ 25 mph +/- depending on the wind. Usually about 175 degrees F, 55# oil. Tabs always up.
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Re: cruising rpm

Post by jcoll »

Tom and I have the same boat and engine configuration and I (and the boat) like 3200 t0 3400 RPM. Boat runs at 19 to 21 MPH indicated on GPS. Closed cooling system temp = 180F gauge and oil pressure 60# gauge readings. I'll assume prop and trans. gear ratio are the same. I also run tabs up. I don't have any fuel in rear tank and the boat doesn't need any tabs to plane nicely.
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