Well, I took my prop off and took it to a shop and found out that i have a 14x17 LH prop. My current setup for those that dont know, is a 4 cyl 117 hp motor with the 270 O/D with gear ratio 0f 2.15:1. I can hit my max rpm (5000) no probs with myself and the admiral, which puts me at 35 mph (which seems pretty good to me). My cruise speed at 4400 rpm is around the 25 mph ish range. Can I or should I re-prop to gain a few mph at cruise range ? I never run at max rpm but wouldn't mind a few more mph at cruise. What does everyone think ? If re-propping is possible for what i would like, what would you recommend?
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4400 is outrageous to me for cruising. My 2855 did 21.5knots at 3400 and my Hat 44 does 14 at 2100 (diesel) downhill.
Is your prop 14 diameter x 17 pitch? What engine and drive?
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The WOT RPM is considerably higher with the AQ125A engine. You'll want to stay within the same WOT RPM no matter which prop you end up with.
Have you considered trying a 15" diameter prop?
BTW, try wording your thread title to include "Volvo Penta" next time.
Rick E. Gresham, Oregon
2850 Bounty Sedan Flybridge model
Twin 280 HP 5.7's w/ Closed Cooling
Volvo Penta DuoProp Drives
Kohler 4 CZ Gen SetComment
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oh PULEEEZE....2850Bounty wrote:
BTW, try wording your thread title to include "Volvo Penta" next time.
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David, the only reason that I mentioned that was because:
1.... it would catch the attention of like boat owners who would be better able to help him.
2.... if would be understood that 4400 rpm is not necessarily outrageous for this engine.
3.... I'll have to think up a # 3.
.
Rick E. Gresham, Oregon
2850 Bounty Sedan Flybridge model
Twin 280 HP 5.7's w/ Closed Cooling
Volvo Penta DuoProp Drives
Kohler 4 CZ Gen SetComment
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#3...i'm still a noob LoL
So if i went to a 15", what effect would that have? Still trying to learn, this is why i am asking, dont wanna blow up my drive or motor.
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The 15" over a 14", will bite into more water, and in theory give more propulsion.
As for pitch, the 15" diameter may cause you to reduce pitch some.
You just need to try different propellers until you find one that allows you to meet WOT RPM, and yet give the best over-all performance.
It's actually trial and error for the most part.
If you keep up on the drive maintenance.... seals, oil, anodes, etc, you will not damage your drive with the AQ125 engine....... not even in 10,000 hours of run time.
You'd dang near have to put sand into the oil to do so.
Rick E. Gresham, Oregon
2850 Bounty Sedan Flybridge model
Twin 280 HP 5.7's w/ Closed Cooling
Volvo Penta DuoProp Drives
Kohler 4 CZ Gen SetComment
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