Hi All You can't buy dynes over here and it is winter where most of you are so maybe you won't mind me asking. I'm looking for advice on what prop to use on my 2008 ETEC 225 HO on a Matrix Sorrento. The Sorrento (pro footer) is similar in size to a Response LX. See http://www.matrixmarine.com.au/site/ind ... to&boat=19 or We do a lot of slow stuff from 11mph disc, 19mph planks and kneeboards, 25mph doubles, 25-36mph slalom course, 38-42mph barefoot. We may have one to six skiers doing any of those all at once although I don't need to pull six footers at 42mph... Wonder if I could... I do have a special strengthened ski pole.... The boat will be fitted with perfect pass, I guess it will be the only E-TEC in the world to have it but I've got it half on all ready. I want to set it up so it is easy to hold speed by hand and not reliant on running PP all the time. Still I can't wait for the stargazer GPS upgrades. All the usual stuff like holeshot, economy and 60mph top end are important to me. But really, I want it to be easy to drive, hold speed well with a strong pull. Must be able to pull out six blokes on standard fibreglass doubles for example. I was thinking a 21" large diameter four blade. The wake charactistics of the prop are also important. I don't want a nasty barefoot wake. One other thing, I would prefer a special looking prop. It is a promo setup that should look great on the trailer. I think a 4 blade would look better. I'm not looking for a 15" show ski special (too many RPMs, too noisy and I should have more than enough horsepower and torque not to need to go that short). Was hoping that others would tell me a 21" would be OK for me and here is some examples of what Evinrude's props have been like for skiiing. Thanks for reading my post, all replies appreciated.
You will probably think this reply is sarcastic, it is not. It is ok with me if you think that though. You need several props: One that looks good on the trailer. It would have a lot of pitch, cup, rake and blades and be worthless at low speeds. It might get you 60 mph on the top end. One for barefooting with a low enough pitch to get a bunch of people up and high enough pitch to get the speed you want. Probably a 17 or 19 of most any design. One for low speed work which would probably be a 15 or 17 with ugly round blades and little or no cup much like the shape of a typical aluminum prop. It could be aluminum and be easily modified. Props with stern lift are not generally pretty by modern double zoomy standards. They are cheap, so you can afford to have at least one in your collection. If you find one prop that does all that you want, buy stock in the company. jim :lol: 8) 8O
If you can find an older OMC SST (not the newer SST II) in a 19 pitch, it should perform ok for all your situations. Nothing will be great for all, but from what I've seen, the original SST's are about the best for general water skiing. They are painted black, so they aren't pretty though.
New style (extended hub) 19 pitch Rebel by Evinrude, and drill vent holes in front of the blades. This will help with hole shot but not sacrifice any thing on top end. Second choice is 4 blade cyclone. This is my plan for 2008 anyway . The old Rebel had a shorter tube that the blade tips extended too and exhaust gas could catch the tips causing cavitation under heavy loads like a big guy on the boom. These props will get you to upper 50's probably and provide decent low speed handling of the acts you mentioned. I can hold 11 no problem for my daughter with the 19 Rebel I have on my 225HO. The 19 that River Rat mentioned would be fine too, but the 19 SST was not as good as the 15, 16 and 17's because the blades did have some aggressive rake to them. Nice boat and nice choice of motor. With any luck I will switch out to the new 3.4L 250 HO in spring.
I run a 19 pitch Mirage Plus on my 18' Hydrodyne powered by an Optimax 225. Not sure it is ideal for my use, though... I'm going to experiment with some different props this summerr. I really think that I would have been better served with a 21 pitch prop for this boat, given my overall use of the boat. I see about 55 MPH with the 19 pitch prop and I'm near the limiter at WOT. I get tons of power for the holeshot but the boat frankly can't handle it anyway due to the design of the tow pilon and the lack of bow weight (notwithstanding the 18 GAL bow tank). If I'm pulling three adults out on deep water slalom starts the pull from the tow pilon wants to pull the bow straight up in the air anyway - so much of the power is wasted on plowing water. You might be able to better use the power on your boat. In order to take advantage of all the power I've got from the pilon I'd need to either add substantial bow balast, get a transom wedge, or both. For speed holding, given the simple family skiing we do most of the time, a 21 pitch is fine and gives me better all around performance with more room off the max RPM at WOT (I've used an aluminum 21 pitch which was flexing under power but was showing 60MPH top end with no appreciable difference in pulling people out of the water for my typical load). If I were pulling show acts, and using the tow eyes along with the tow pilon for heavy acts, then 15s and 17s might make sense. For my use, I won't even buy 15s or 17s. I can't comment on the 4 blades - or the High Fives - because I have no experience with them. Dynegreg or Dynebob could better speak to the High Fives. The other issue here is vented props - and the use of vent restrictions or vent plugs. My 19' Mirage Plus has the full vent plug in. You feel almost a touch of "turbo lag" at take off as the prop doesn't slip as much with that vent plugged and it loads the engine up pretty good right away. I've used a Stiletto 19' which is a very similar prop but with the vent open and I probably get more immediate power with that prop and pretty much identical top end as compared to the Mirage Plus - but the Mirage Plus with plugged vent will accelerate quicker in the mid range as the prop hooks up sooner than the vented Stiletto. For whatever reason, the boat will "wheelie" better with the Mirage Plus, as compared to the Stiletto, as I discovered in a somewhat scary manner. Unlike many of the members of this website, my primary goal is not necessarily to be able to have a perfect setup for show skiing or speed holding for slow speed work. 75% of my time is spent pulling innexperienced waterskiiers at moderate speeds for two or three circles - then I pick up another skiier and start the drill over again. I'm typically using almost no throttle to pull people out on 95% of my runs. Most of the remaining percentage is pulling modestly experienced slalom skiiers. I do pull some knee board, trick ski, disc, canoe paddle, and the like, but it is such a small percentage of the time that I don't really want to rig the boat to make that type of pulling ideal. Also, unlike most others (perhaps?) on this website, I do like to put the hammer down and watch the needles move for some amusing top end - even though the Hydrodyne 18 is not a true "speed" platform. So I will buy two more props over the winter - not sure what yet - and will report the results and do some videos for the members on Hydrodyners. Like you, I'd like to be able to see 60MPH at WOT. There's just something about hitting that number. Maybe that's because I've driven a "family" boat for years that can hit in the 50's and there's a part of me that believes that a very expensive 225HP engine on perhaps the worlds most upside down valued 18' Hydrodyne should do a bit better when screaming down the lake... Or, perhaps I just feel that when I blow by the guys in the inboard ski boats (and indeed I do) I should blow by them faster... :twisted:
I have never actually used a 19 SST. Just the 15 and 17 for our show team. I just assumed that they would have been the same general shape as the lower pitch versions.
Still a decent prop, but once you get above 17 pitch there are many good options. If you can find one used and cheap it is a good prop to grab.
He said 60mph is important. A 21 won't do it with his gear ratio. 5800 is the top of the rpm range. .1 is the typical slip. The motor might hit 6000 or slightly more on the limiter but the power is probably at 5800 or less. The boat is 23 ft including the motor, so it is probably a 21 with a 7' 3'' beam. That is a big boat. Here is the prop calculator. http://www.rbbi.com/folders/prop/propcalc.htm A 22 or 23 prop is going to be needed to hit 60 with the 1.86 gear ratio in my opinion. It might pull up 6. The prop shaft rpm will be so low at 11 mph that it will dig like mad. In my opinion, jim
Cool. Jim knows this stuff down to a knat's A _ _. Jim - what are the vital stats for the 225 Opti? I think max RPM is 5750. Gear ratio? I want to play with that calculator you posted...
Mark, I think your gear ratio is 1.75. You can plug in known speeds and rpm's and find the slip. The speed has to be accurate though. .1 slip is typical. It could be a little more or less. Props are not alway as advertised either. When using a low pitch prop, they will generally hit the limiter which is usually above the recommended range. jim
