Prop change?
Renate Marie
fuel-injected Mercruiser Horizon which was new in 2008. It's rated at
just over 300 HP. The BorgWarner V-drive (2:1) has just undergone a
major overhaul/rebuild. The boat came with a mounted 19 x 20 RH prop
(3 blade) and a spare 18 x 16 RH (4 blade). We've been told that wide-
open throttle RPM should be somewhere between 46-4900. The problem:
We've been able to achieve WOT RPM of only about 3000 with the 3 blade
and 3400 with the 4 blade prop. We suspect a significant reduction in
pitch will go a long way towards improving the situation but have no
experience with these matters. Can anyone offer guidance as to what
would be the optimum prop size/pitch to achieve the desired
performance? Any other suggestions that go beyond the prop would also
be welcome. Thanks.
Phil
pmg
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stanleym...@centurytel.net
Renate Marie,
I Have a 26 ft tolly and installed a Crusader 350 engine in 2008, it
came with a 18/19 tree blade and with the new engine on sea trial we
reached 4950 RPM and 26 knots headed up stream in the Columbia River at
Portland Oregon. I am very happy with the performance. It sounds like
you have other problems as you should get close to high RPM's with the
19/20. I also had the v-drive rebuilt when we installed the new engine.
Possible Jeff at Cook Engine (503-289-8466) in Portland Oregon could
help as he installed my engine.
Stan Jackson
Quoting Renate Marie <heyju...@gmail.com>:
> We bought a 26 ft (1978) Tolly last year. The motor is a 350 (5.7)
> fuel-injected Mercruiser Horizon which was new in 2008. It's rated at
> just over 300 HP. The BorgWarner V-drive (2:1) has just undergone a
> major overhaul/rebuild. The boat came with a mounted 19 x 20 RH prop
> (3 blade) and a spare 18 x 16 RH (4 blade). We've been told that wide-
> open throttle RPM should be somewhere between 46-4900. The problem:
> We've been able to achieve WOT RPM of only about 3000 with the 3 blade
> and 3400 with the 4 blade prop. We suspect a significant reduction in
> pitch will go a long way towards improving the situation but have no
> experience with these matters. Can anyone offer guidance as to what
> would be the optimum prop size/pitch to achieve the desired
> performance? Any other suggestions that go beyond the prop would also
> be welcome. Thanks.
>
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