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  Prop/Engine matched? 22' Revenge WD

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Author Topic:   Prop/Engine matched? 22' Revenge WD
quattro20vt posted 07-29-2003 02:31 AM ET (US)   Profile for quattro20vt   Send Email to quattro20vt  
My new to me '89 22' Revenge WT WD has a Mercury Laser XRi (2.4 L 220 hp V6) with a Michigan Wheel stainless Ballistic 17" prop.

This is a STRONGLY cupped prop. So much so (IMO) that when I fully trim in (motor down) to start, the motor bogs/lugs such that it often won't spin past 2000 rpm. By trimming out, I can get the motor to spin quickly, but with the resultant bow rise. My current solution is to start trimmed out, but as soon as the engine spins past 2000 rpm, I trim in.

In addition to this, I am getting max RPM of only 4600-4800 rpm, with a 36mph (GPS) top speed--well below the engine's max hp rpm rating of 5600-6000 rpm. I also seem to get a lot of torque lift (list to port) when straight, which might also be due to kicker (Mercury 15 hp) mounted on a bracket on port side of WD.

Questions:
1. Is the Ballistic prop's cup causing this bog/lug?
2. Can I minimize this bog by ventilating the prop (see Mercury's site on their PVS system). Interestingly, Michigan's 21" and higher pitched Ballistic props have vent holes drilled in the hub. What size holes do I drill?
3. Do I have the right prop? Despite my max RPM, Mercury's site is suggesting a 19" pitch prop. Interestingly, my last boat had a Mirage 19" prop, and that prop is available for testing...yet that seems counterintuitive given my max RPM.
4. Anything else I might look at eiher prop-wise or to attain max rpm closer to 5600 rpm?

Thanks!

jimh posted 07-29-2003 08:00 AM ET (US)     Profile for jimh  Send Email to jimh     
Mercury has a line of propellers that have adjustable vent holes in the hub. By installing inserts of various sizes you can adjust the amount of ventilation. The concept of this propeller is that at low speeds the venting of exhaust gases through the hub vents will intentionally create cavitation. This effectively reduces the pitch of the propeller, or at least it allows your engine to turn it more easily at low crankshaft speeds. The cavitation will allow the propeller to slip at low speeds, but also prevent you outboard motor from lugging.

At high speeds, the exhaust gases tend to stop flowing through the vents, and the venting stops. By this time, you engine speed is into a horsepower or torque range where the engine can handle the full pitch of the propeller.

This type of propeller might be good for your situation. In actual use, you get a feeling of starting in low gear then shifting into overdrive once the propeller stops venting. You can also reduce engine throttle and maintain the non-venting condition so you can cruise at lower throttle settings, too.

Peter posted 07-29-2003 08:49 AM ET (US)     Profile for Peter  Send Email to Peter     
1. No, I don't believe that the cupping is all of your problem although it may be contributing some.

2. Don't drill holes, I don't believe that they will solve all of your problems. (See 3 below).

3. I believe that you have the wrong size propeller.

Plugging in 6000 rpm, 1.87:1 gear ratio, 6 percent slip and a top speed of 42 mph (a bit optimistic here), the propeller calculator in the reference section here suggests that you should be using a propeller with a 15 inch pitch.

To give you a comparison, my 22 Revenge WT (no Whaler Drive) is pushed by a 225 Yamaha (large 3.1 liter block) having a gear ratio of 1.81:1 (more propeller rotations per engine rotation than a 1.87:1) turning a 17 inch propeller to a WOT engine speed of 5300 rpm and a top speed of about 43 mph (close to predicted top speed).


The ventilation holes will help the engine wind up at the hole shot but I don't believe that it will do much of anything for the top speed problem that you are having. Your inability to achieve the proper WOT rpm range is the likely result of being over propped.

In my opinion, in this case, the Mercury propeller calculator may be giving you bad advice regarding increasing the pitch to 19 inches.

I would try a 15 inch pitch propeller to see if you can obtain the proper WOT operating rpm. If not, then you have a problem with your motor.

quattro20vt posted 08-11-2003 02:08 AM ET (US)     Profile for quattro20vt  Send Email to quattro20vt     
An update on my prop/rpm situation

First off, I misspoke when I started this thread. The Ballistic prop I have is a 14.5 x 19p, not a 17p. But as my experience shows, a 19p prop may not be a 19p prop!

Last week, I got around to calling for more opinions...I started with a propeller shop (new, used, repair) here in the Seattle area, as well as contacting a respected contributor to these forums (he may identify himself at his discretion). Both were of the opinion the Ballistic prop was sub-optimal...not just for my application, but in general (words from the prop-shop guy are not repeatable in this family-oriented forum :) Both thought it worth my time to test out the boat with the Mirage from my old boat.

This afternoon, I did just that. The prop is a ca. 1991 Mirage 15.25 x 19p (no PVS slots). Conditions: minimal traffic, light chop (Lake Washington's East Channel). Results: 40 mph @ 5000 rpm max. This is 4mph and 400 rpm more than with the _19p_ Ballistic! Other observations: better bow lift at speed, and no problem getting out of the hole, even if trimmed in fully. I didn't have an extended time to experiment today, but I seem to have less torque lift, and I could more easily trim to balance out helf effort.

Conclusions: 1) the _19p_ Ballistic behaves like a 21p prop, relative to the Mirage. 2) I really like the Mirage :) (the wife isn't going to be happy about buying a new wheel)

Next test: my neighbor's 25' Searay has a 15.5 x 17p Mirage off a Bravo I. If that gets me to 5400 rpm, I'm willing to write off the missing 200 rpm or so to the engine's age (1988 Laser 220 XRi). For kicks, I may try the Ballistic on my old 18' Searay (Merc 135)--with my luck, it'll work just fine there!

Q: Does anyone know if the current Mirage Plus is the same prop as the original Mirage, just with PVS slots/plugs?

Peter posted 08-11-2003 07:11 AM ET (US)     Profile for Peter  Send Email to Peter     
Your new data suggests to me that a 15 inch pitch propeller is the right size as the propeller calculator suggests. You should prop your engine so that it is on the high side of your WOT range. Based on the results with the 19 inch propeller, the 17 inch pitch propeller will not even put your engine on the low side of the WOT range, thus you will be "lugging" the engine with that propeller. You really need to get another 800 rpm and only the 15 inch propeller will get you there.

Sal DiMercurio posted 08-11-2003 11:58 AM ET (US)     Profile for Sal DiMercurio  Send Email to Sal DiMercurio     
I'm going to suggest going to a Stiletto 14.25 x 15 [ 1/2 the price of a similar merc prop ] & try raising the engine a set of holes.
Without raising the engine you should get 5,800 rpms, right in the middle of your recommended rpm range.
I'm not overy fond of Ballistic props to beguin with.
Sal
lhg posted 08-11-2003 01:56 PM ET (US)     Profile for lhg    
To confuse you further, I recommend a 17" Mercury prop, for which Mercury's prop charts that I have show a load range of 2900-5000# and 38-48 MPH. This should work for your rig, as for a 15" prop, they show load range of 3200-5500#. Using a 17" pitch prop assumes a strong engine.
I would use the 4 bladed Offshore Performance model, as the Mirage has a lot of blade surface you may not be able to turn up. It's a fairly heavy boat for a single 200 (engine puts out the same as a current 200 EFI).

I think you have learned what many already know about those wierd Ballistic props. A deal is not always a deal.

quattro20vt posted 08-11-2003 03:05 PM ET (US)     Profile for quattro20vt  Send Email to quattro20vt     
Following up on LHG's "a deal is not a deal," I hear you loud and clear.
...the Ballistic came with the boat when I got it a month ago. agree it is a weird prop.
...I have no experience with the Stiletto...even it if is only 1/2 the cost of a Mercury, if I get it wrong...
My inclination, once I figure the pitch, is a Mercury prop--do it once, do it right.

LHG--what's your thinking on the 4-blade offshore--are the blades that much smaller that 4 of them present less blade area than the 3-blade Mirage?

As I mentioned, I'm going to hit up my neighbor to borrow his 17" Mirage wheel...only concern is since it's on a Bravo I, it is likely a solid hub prop. For testing, I hope that won't be an issue. Hope to have some ideas here soon...this thing called work interferes with my boating ;)

New question: what realistic RPM should I expect WOT? Comparison points: the Laser 220 XRi was simply the EFI version of the Mercury 200 carb'd 2s. This is the old 2.4 liter V6 (c'mon Mercury--your book says 2327 cc--that's 2.3, not 2.4 liters!) The Mercury service manual I have lists the 200's WOT rpm as 5300-5800 rpm while the Laser is rated at 5600-6000. Today's Mercury 200 EFI, an honest 2.5 liter, is rated at 5000-5800 rpms

lhg posted 08-11-2003 04:54 PM ET (US)     Profile for lhg    
For a great price on a Mercury prop, go to offshoreperformance.com. I think any of the performance designs are about $400.

Louie Kokinis here, with a 22 Guardian, has indicated he greatly prefers the 4 bladed Offshore (better hole shot and acceleration, great holding, hull lift and mid-range speed) over his Mirage prop. The Mirage prop will be slightly faster top end, and have a larger diameter, but are mostly recommended with the 3.0 liter 225-300 Hp engines. If speed is your interest, the Mirage will be faster on a heavier, twin engined boat. I think most new Whaler Outrages come equipped with Mirage props.

If however, after testing your friend's Mirage, you like it, go for it, and play it safe.


brade07 posted 11-16-2005 07:53 PM ET (US)     Profile for brade07  Send Email to brade07     
I have the same engine and im running a 21 pitch prop.
The xri should be reving at around 6000rpm at WOT, I have this on a 21ft checkmate hitting around 64mph, ive also tried a 23pitch and 25pitch and have got this boat up to 70mph at WOT.

a 15 pitch is much too small for this engine, the smallest you want to go for fishing, or skiing, or even cruising is a 19 pitch.

jimh posted 11-17-2005 12:35 AM ET (US)     Profile for jimh  Send Email to jimh     
This recently added advice on propeller pitch is completely at odds with my own extensive tests with the same boat and another 225-HP motor. A 15-inch pitch propeller proved the best. You can see the extensive test results in the REFERENCE article.

http://continuouswave.com/whaler/reference/propellerWDSingle.html

There is no way in the world a 21-inch propeller will work in this application.

Tom W Clark posted 11-17-2005 12:48 AM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Jim,

I agree. It makes no sense to compare the performance of one particular motor on two completely different boats.

A 21' Checkmate is not a Whaler 22 Revenge Walk Through Whaler Drive. *chuckle* Not even close.

linust posted 11-17-2005 02:47 AM ET (US)     Profile for linust  Send Email to linust     
Wow...amazed to see this 2 year old thread back on top.

Since I didn't update this thread with final results, I'll do that now...

Sometime in the fall of '03, I acquired a Mirage Plus 17p wheel. I don't recall exact details, but it did allow the motor to turn more revs--I believe it got to the 5400 rpm range as I anticipated, with speed of somthing over 40 mph (41? 42?). However, I was still not thrilled with the setup. In addition to poor power, noise and fuel (un)economy, I also had some reliability issues one evening.

In Dec '03, I started a topic on repower thoughts for a 22' WD. This discussion covered singles vs twins on the WD, power ratings, and a running production change on 22' WD hulls. See > http://continuouswave.com/ubb/Forum4/HTML/002233.html

Ultimately, in Jan '04, I repowered with a 225 Opti. I continue to run the 17p Mirage Plus today. Here's my report following the repower > http://continuouswave.com/ubb/Forum4/HTML/002306.html

LHG posted 11-17-2005 02:36 PM ET (US)     Profile for LHG    
With a loaded up boat and full canvas set, 44MPH and 3.4 MPG makes a single 225 Optimax, with measly 3.0 liter cubes, a pretty hard engine to beat on a 22 WD Revenge. And now, one can buy a 3 star 3.0 liter 225 Optimax XS with even more power, and it is lighter weight and faster than the 3.3 liter (cubes count???) 225 Etec, with a faster, better, Sportmaster gearcase design according to Bass and Walleye Magazine's test.

It sounds like linust made an excellent decision.

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