260 Chrysler RPM's

[daniel77]

Im new to this forum and we just purchased an awesome 1976 32f. we love it. My questions is on what a normal cruising speed rpm would be to get on plain. The gentleman I purchased it from recently passed away and the family was forced to sell it. His son told me that the owner in 20 years never ran the boat beyond 1600 rpm. What would be a safe RPM's to run this boat for a comfortable cruising speed.
Thx

[prowlersfish]

Assuming its propped right 3000 is a good cruising rpm range a little more or less is fine depending on what feels good . of course nothing wrong with a slow cruse at 7-8 knots .


The question is .. is the boat propped right ? at wide open (wot) you should be getting 4000 rpm plus with a clean bottom .

On your engine I assume you mean a 360 ? (250hp)

[captainmaniac]

The Chrysler 360 (cubic inch) is supposed to put out 260hp. The right prop for mine ('79 version) is 16x16 cupped. I believe it is a 1.25" shaft.

At 1500rpm I do about 8 knots, and get about 1.5 mpg overall. Basically this is displacement speed, fast enough to give you good control, economical, and the top end of the speed range you can go without starting to push a lot of water.

You will climb on plane at or just above 2000rpm (with trim tabs fully down) but the boat will be fighting to stay there. Perhaps 10 knots at this point

The most economical planing speed is in the 2800-3200 RPM range, probably about 16-20 knots depending on conditions (wave heights vs flat water, wind on the nose / abeam / from behind). At this speed you are well up on plane and not just pushing water (as you would be around 2000-2400rpm), and just shy of opening up the other set of barrels on the carbs. As your speed climbs past 14-15 knots, you will actually feel the hull 'free up' from the grip of the water.

[daniel77]

Hi Guy's
Thanks for your input. Its a great help. And yes they are Chrysler 360's. All that we have done so far is the sea trial, this weekend a few buddy's and I will take her out and see what she can do. As far as I know she does have the correct props.
Thanks Again

[bjanakos]

The Chrysler 360 (cubic inch) is supposed to put out 260hp. The right prop for mine ('79 version) is 16x16 cupped. I believe it is a 1.25" shaft.

At 1500rpm I do about 8 knots, and get about 1.5 mpg overall. Basically this is displacement speed, fast enough to give you good control, economical, and the top end of the speed range you can go without starting to push a lot of water.

You will climb on plane at or just above 2000rpm (with trim tabs fully down) but the boat will be fighting to stay there. Perhaps 10 knots at this point

The most economical planing speed is in the 2800-3200 RPM range, probably about 16-20 knots depending on conditions (wave heights vs flat water, wind on the nose / abeam / from behind). At this speed you are well up on plane and not just pushing water (as you would be around 2000-2400rpm), and just shy of opening up the other set of barrels on the carbs. As your speed climbs past 14-15 knots, you will actually feel the hull 'free up' from the grip of the water.

This is a real good explanation. On my previous boat, I would plane at about 2800 RPM. At that point, once it left the water, the rpms would climb since it was pushing back less water, and then I would have to trim it back to 2800.

[daniel77]

Thanks again for the great explanation, Much appreciated !!

[Reel Easy]

That's great info for me too. That's were mine is. I tried it out yesterday. Thanks