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ContinuousWave: Whaler Performance
22-Outrage Performance and Propellers
|Author||Topic: 22-Outrage Performance and Propellers|
posted 11-18-2002 03:04 PM ET (US)
Since shortly I own a BW 22 Outrage 1990 with two Mercury 115 HP. Boat and Engine are in pristine condition.
Top speed 32 knots with 12 inch diameter and 21 pitch aluminum props. Vessel should run at least 40 knots.
What props do I have to use??
Reading all those articles I have to give some information. Vessel runs at 3200RPM approx 21KN. At 5200 RPM vessels runs approx. 32 knots. To my idea that is not logical. It should be 40 KN. Should there perhaps be some water in the hull, making the vessel more heavy?? Or what could be wrong??Albert Dal.
|John from Madison CT||
posted 11-18-2002 04:12 PM ET (US)
32knts does seem slow. What RPM's are you spinning at WOT? That is very important.
posted 11-18-2002 04:18 PM ET (US)
At WOT 5200 RPM on both engines easily.
posted 11-18-2002 05:06 PM ET (US)
I would get rid of the aluminum props, in favor of Mercury's 20" Laser II performance props. With engines installed in the third (middle) holes, you should get about 45 mph out of it. These props will also give you a better ride, with more bow lift increasing speed. The Mercury 4 cylinder 115's are not particularly fast engines, at least when compared to their in-line 6 predecessors. The Laser II props cost about $400/US each. You can order them from offshoreperformance.com
posted 11-18-2002 08:40 PM ET (US)
Albert,I was clocked at 39-MPH with my 22-Outrage, with twin 70-HP Yamaha 17" props at 5400-RPM with two people aboard 35-gallons fuel. Thought I'd just give you a comparison. With twin 115s I would think that you should run at around 45mph, your RPM sounds about right but the speed doesn't, 21" pitch sounds high.
posted 11-18-2002 11:11 PM ET (US)
I had to paste this together from three separate threads. Please use the REPLY button, not the NEW TOPIC button when composing additional messages on this topic!
posted 11-19-2002 02:15 PM ET (US)
Thank you JimH for your intervenience.
Hope to get even motre responses. Wonderfull.
posted 11-20-2002 02:39 AM ET (US)
I have received several very different opinions/advises from prop-shops.
My present idea is high fives. Could anybody advise his experience with high fives in this configuration of boat and engines.
posted 11-20-2002 08:51 AM ET (US)
Take close note to Larry's reply regarding engine height. Having a expensive well designed stainless steel prop on an engine that is mounted too low will not solve the problem. The anticavation plates should be, at the minimum, flush with the bottom of the hull, and then experiment with raising them above the hull bottom.
One caution on stainless props. If you cruise where you can run into hard things, like rocks, as opposed to mud and sand....be very, very cautious. When you hit a rock with an aluminum prop, a good portion of the time the blade will snap before doing serious damage to the prop shaft, bearings, etc. Not the case with a stainless prop.....
posted 11-20-2002 04:35 PM ET (US)
The ultra smooth High Five's would work well on the twin 115 rig. Mercury even recommends them for offshore holding. They are not quite as fast top end as a Laser II, and because of the 5 blades, need to have the engines set in the third mounting hole. If they are run fully submerged, as in water skiing, pitch has to be dropped by 2" because of the huge bite they take and blade drag. But since 20" is already as low as they are made, engines will have to be run 1 1/2" high to achieve max RPM.
I think Clark Roberts runs one of these and really likes it.
posted 11-21-2002 08:56 AM ET (US)
Thank you all. Most helpfull.
At present the engines are taken off the boat for maintenance. Meaning no problem in adjustment to any hole.
My most frequent travelling speed is approx 20 knot at 3200RPM. Now I think that my present props are uneconomic and this speed could be achieved at even a lower RPM with the right props.
As the port where the boat is lying, does not have a station which provide petrol (only diesel) and I have to refill the boat by jerrycans, I prefer a most economic fuel consumption at 20-22 knots.
Than do I go for Laser II and what pitch or do I go for the high fives at 20 pitch as I understand is the right pitch??
posted 11-22-2002 02:56 PM ET (US)
I understand that for Laser II props or High Fives it is required to mount the engines 1 - 1.5 inch higher.(third hole)
That means that the cavitation plate is above the water and so without function.
I do not understand why such is required.
posted 11-22-2002 04:28 PM ET (US)
If you decide to go with Merc stainless props, don't worry about extra damage should you hit something as was mentioned earlier. The new Merc props come with a new hub design that will break free if hit hard.
posted 11-29-2002 03:11 PM ET (US)
Is anybody out there who knows why it is said to be required to mount the engine(s) 1.5 inch higher on the transom when using Laser II of High Fives as props????????
posted 11-29-2002 04:52 PM ET (US)
I have no knowledge or experience with those particular propellers. I do know that some propellers are designed to run at the surface of the water. My understanding is that these "surface" or "surface-piecing" props work best when they are able to grab some air. They are actually designed to perform best when they ventilate.
posted 12-02-2002 09:00 AM ET (US)
Ok thanks, but what happens if you do not mount the engiens the 1.5 inch higher but just normal.Meaning the cavitation plate in line with the undersite of the transom.
posted 12-09-2002 04:23 PM ET (US)
Mercury's performance lines of vented SS props, such as Laser II, Trophy, High Five, etc. CAN be run fully submerged, but generally when doing this pitch will need to be selected 2" lower than when using an aluminum or conventional SS. The issue is whether the prop is available in a low enough pitch range. If you need less than 20" in pitch, you will have to select an aftermarket line, or select a 4-bladed Trophy Plus, which are available in 19" and 17" pitch, but are mostly recommended for bass and flats boats.
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