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View Full Version : 3 Blade vs. 4 Blade Prop



Randy_M
05-23-2011, 11:42 PM
I need some information and recommendations. The current '88 Saltare with a 454 is running a 14x13 LH 3 blade prop that needs some repair to be 100%. We are currently considering a 4 blade replacement instead of repairing the 3 blade prop. We have seen two different recommendations for the usage (wakeboarding, skiing, tubing, kneeboarding, and a possible parasail) of this boat when using a 4 blade prop. The first is a 13x13 LH and the second is a 13x14 LH prop. There doesn't seem to be much difference between the two. We are looking for an all around prop that will provide the best across the board service and fuel economy. Is anyone using either of these 4 blade props and if so, what is your opinion and recommendations of them? Thanks.

wotan2525
05-24-2011, 12:41 AM
You're going to get a bunch of advice. The truth is that nobody really knows (because most people don't ever try more than a couple of props.)

The other thing is that when people spend $400 on a prop they feel some kind of passion towards it being the "best" one and defend that theory very loudly.

I'd call Acme or OJ and tell them what the boat is, what you use it for, and then take their recommendations. They are the experts (and in mind, the only ones that really know much about the "science" behind props.)

csuggs
05-24-2011, 08:20 AM
Wotan gives good advice. You can also call and talk to Vince at Discount Inboard Marine (www.skidim.com). I purchased a new Acme prop from him this year - they have a trial period that you can run the prop and exchange it within 30 days for a different one as long the prop is not damaged.

haugy
05-24-2011, 08:43 AM
Yep, good advice above. Props are like tires, everyone has their size and type that they swear is awesome.

Ptownkid
05-24-2011, 10:21 AM
From everything I have read.....today's 3 blades are better for what we do with our boats. As for size...I have no idea.

sybrmike
05-24-2011, 10:30 AM
I'd call the experts & chat with an open mind and honest description of your wants/needs. I think the opinions here & elsewhere on the web vary widely because there are so many different boat/engine/trans/usage combinations. I spoke with two different guys at Acme several months apart & they both recommended the same two options for my application. Although I've yet to use it on the water, there's finally some comfort in a consistent message from the manufacturer.

I don't know about OJ, but don't expect Acme to recommend a 4 blade for a Saltare with 454 and 1:1 trans (I think they're more for gear reduction tranny's and v-drives).

jet
05-24-2011, 11:57 AM
Im not getting in this one. lol


GO 4-Blade!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Ptownkid
05-24-2011, 12:19 PM
but you just did...so that being the case, what is your love of 4 blade based on? Almost every recommendation story I've ever read (which are more often than not based on the user having called acme or OJ) all say 3 blade was what they were told to get for wake related activities.

So let's have this discussion with info backing up personal preferences so that we can all finally educate ourselves.

csuggs
05-24-2011, 12:45 PM
I have run both 3 and 4 blade 13x13 OJ. The 3-blade had slightly more top-end but the 4-blade had a considerably better hole-shot. This year I will be running a new 3-blade Acme that I'm told will have the top-end of the old 3-blade with the hole-shot of the old 4-blade. How does that work? I guess it's all in the shape of the blade.

Ptownkid
05-24-2011, 01:14 PM
The recent 3 blades are far superior to the old 3 blades because of them being precision cnc'd now. They have far more surface area, or at least that's what I've read.

jet
05-24-2011, 01:39 PM
OK...but thats like saying what kind of girl do you like?? A 4-Blade has more BITE and more SURFACE area Period! Thats where it has Its advantage..yes you can pick the wrong gearing in it or pitch but it has more BITE and it has more surface area. A smaller 3-blade will spin faster, use more rpm's and burn more gas. Power boats want to spin the prop very fast for speed..a tractor (which is what our boats are made for) want more BITE for moving weight. When I started putting 1700-1800 lbs in my boat the wake was great but it took me a football field and full throttle the whole way to get up to plane..it was a HUGE waste of gas and LOAD on my engine. AFTER switching to a 4-Blade I use 10-20% throttle now and the boat is up to plane in 2 to 3 boat lengths..GAS mileage is WAY down and my engine doesnt work hard anymore. Im sure I cant go 40 mph anymore but I dont care..Im a wakeboarder. Now having said that there are variables and this is where the opinions and choices come in. My trans is a 1:??:1 trans Power Plus option (8-10?? I cant remember) which is geared more direct so my boat RESPONDED very well to the BIG 14x14 bladelike a drag gear would on the track. Now we put that same 14x14 on my buddies Malibu he has a 1:1 trans to but the middle# was higher like a hwy gear..his ended up being like a 1:28:1 trans and that higher number is more like a hwy style gearing and wouldnt push the 4-blade. Not enough rpm's so it was like having 2-hwy gears in there. He is now trying a 3-blade like a 13x9 pitch which has ended up being a better match for his Hwy like gears in the trans. I think the older boats with the more direct 1:1 ratios respond really well to a bigger prop but the new trans has way more gearing in it and might not benifit from a 4-blade as much. So heres what you do. You call the factory, tell them how much weight and what YOU want the boat to do and they will recomend a starting point BUT, make sure you have trade up or down options so you can try 1-2-3 props and find what you like. Easy as mud!! Right! My opinion is that I DID NOT WANT A 3-blade anymore. I also told the acme guy I was pushing 1800 lbs and I wanted the biggest 4-blade I could get. I dont see any of the new big boats coming with 3-blades on them so why would you pick one for your boat IF you want to wakeboard. I hope this helps, as a sales guy I just try and make and keep things simple. Jet

Ptownkid
05-24-2011, 02:06 PM
I will buy most of what you are saying, as a lot of it does seem to be logical...but,


Through the implementation of precision manufacturing and design improvements, Acme Propellers are giving the 3-blade the reputation it deserves. Acme is consistently holding tolerances never before achieved in propeller production. This accuracy makes the Acme 3-blade incredibly smooth. In addition, the blade area of the Acme 3-blade has been expanded to equal that of the Acme 4-blade. The translation? The Acme 3-blade has raised the performance bar. From an awesome hole-shot to an unmatched top end, and all the smoothness throughout, the Acme 3-blade leaves nothing to be desired. We believe it has an edge that everyone will appreciate. On the other hand, please do not mistake our excitement as a lack of appreciation for the Acme 4-blade, a proven winner.

and therein lies one of the big problems with internet advice, it's not always based on fact. I will however keep looking at the 4 blades based on your experience and couple that with some more reading.

wotan2525
05-24-2011, 02:15 PM
Jet -- You're actually quite wrong. New CNC Acme and OJ 3-blades have the same surface area (or more) as their 4-blade equivalents. All props now have more surface area and more cupping than the props that came stock on our boats.

You're comparing an old 3-blade prop to a new 4-blade prop and then acting like that's the only difference. Even worse, you're preventing your theories as FACTS. PERIOD. They're not... they're just your opinions and the shadetree observations that you're using to form those opinions.

I've run 3-blade props and 4-blade props. 13" and 14" props. I have 3 props that have been pitched all over the place throughout the years. You know what I've learned? I can take two different 3-blade 13" props with the exact same pitch and cup specs and get wildly different performance. Props have very complex profiles and we should leave the ins and outs to the people that do nothing but deal with their specifics day in and day out.

I'm so sick of prop threads.... OP -- Please, just call Acme or OJ. ;)

jet
05-24-2011, 05:58 PM
Slow down girls..slow down..I knew I didnt want to get in this email..yall are just looking for someone to jump on. There was NO facts given in my email..just a easy way to understand it and my OPINION..back off! I know surface areas are getting close but even if they are equel..If I had 4-arms and you had 3 arms I would still kick your butt!

LMAO!!!!!!!!

Mani
05-24-2011, 06:25 PM
Call Jim at Acme Propellers. He fixed me up with a 13X11 3 blade for a very decent price. It's quite an improvement over the old prop, but then again, it's the only prop change I've ever done in my boating career.

You can hear all sorts of stories on here, but in the end, you should call someone who does this for a living, and has engineers backing them up.

Ptownkid
05-24-2011, 08:25 PM
Slow down girls..slow down..I knew I didnt want to get in this email..yall are just looking for someone to jump on. There was NO facts given in my email..just a easy way to understand it and my OPINION..back off! I know surface areas are getting close but even if they are equel..If I had 4-arms and you had 3 arms I would still kick your butt!

LMAO!!!!!!!!

Easy Tiger...I'm personally not looking to jump on you (at least not in the verbal sense, possibly in the literal sense, you're not a bad looking fella, lol.), but you did present the surface area thing as fact the way you worded it, and even if it's just a personal opinion, the manufacturer's documentation disagrees. That quote I pasted above is from Acme's site. So here is a fact, Acme's three blade props have an surface area EQUAL to their four blade, end of discussion. That aspect is not open for debate unless the manufacturer themselves are lying.

I did clearly point out that you opinion has given me food for thought based on your experience with a four blade, so don't get all huffy as I meant no disrespect. Just trying to get some clarity on the pros and cons and I do realise that the best place to get advice is straight from the manufacturer, but I do care what others think about the props they actually have with regards to real world performance.

Look at it this way, maybe by debating these issues we can actually present some solid factual info to future question posers...

Cheers

Hagman
05-25-2011, 01:06 AM
A long time ago when I got my first new boat a (clamp on ) the dealer asked me to go home load the boat how I planed to us it and he would take several props out on the water to see which one would work the best for the way I was going to use the boat. I think this is still a good way to make your choice on a prop . All boats run out different . The same goes for props. The combo that your buddy with the same outfit has mite not work as well for you. Personally I changed to a fore blade. It seems to run just a little smoother over my best 3 blade and I think it makes the wake just a little softer.
And Ngavdba your not alone. I’m over 50, no tower the best skiing is a driver, 1/4 tank of fuel and a 6 pack with a little ice.

supramariah#1
05-25-2011, 06:34 AM
Hey now. I am 32 and I love skiing and kneeboarding.

I havent seen the threads about props before. This is good stuff. I was gonna keep my prop but now... I want a new one! (thanks a lot! Now i need more money again!) I need better out of the hole performance to pull me up slalom SKIING not wakeboarding. lol Getting up on a wakeboard is like sleeping.

1.23:1 means the prop spins faster than the motor correct? Also altitude has something to do with it as well? Just asking so I know what to tell ACME or OJ when I call them.

cadunkle
05-25-2011, 07:51 AM
1.23:1 is gear reduction, just like gears in your car. The first number is transmission input shaft, and the second is output shaft. So this would be read as, for every one turn of the output shaft, the input shaft turns 1.23 revolutions. Your engine RPM will always be 1.23 x shaft speed.

jet
05-25-2011, 10:56 AM
A little clarity. Yes, I was speaking from going from my old 3-blade to a new 4-blade. That was my intent....and thats where I WANTED MY reply to go..my opinion..period! I overstepped talking about the NEW 3-blades because to ME they were not even a option for me. I wanted the BEST not middle of the road gains-(my opinion) The 4-Blade was the LAST big upgrade I did and it should of been the 1st thing I did. THE GAINS WERE SO INCREDIBLE!!! It was like putting a SUPERCHARGER on my engine and I want to share that with yall. I wasted so much time and so much gas and wear and tear on my engine. Lets keep this REAL simple..call your supra dealer and ask him which new model comes with a shiny new 3-Blade?? NONE!! Period!!

Ptownkid
05-25-2011, 01:28 PM
That is understandable...but there's two reasons why the new boats come with 4 blade props. The first being the gearing afaik, and the second, and this is the big one, people's perceptions of 4 blade props being better no matter what.

I for one am glad you got in on this talk Jet, different perspectives and opinions are good, even if other don't agree with you. If all we ever got was one sided opinions, no one would ever learn anything.

csuggs
05-25-2011, 02:04 PM
When I bought my new prop I had no idea what to get and I wanted an unbiased opinion from someone that sells both Acme and OJ so I talked to Vince Dougherty at Discount Inboard Marine. After asking me many questions about my boat and how I wanted to use it, he was able to give me a couple of choices, but he did recommend one over the other - which is the one I purchased. Even more important to me than getting his opinion is the fact that if I don't like it even after I use it for a month, he will take it back and send me something different to try out. How can you go wrong with that??
Call Vince or Richard @ 803-345-0996

csuggs
05-25-2011, 09:26 PM
Thanks Daniel. I appreciate that.
I sincerely hope to get my boat wet this weekend - it looks as if the weather and the river level will finally cooperate! Then I can let you know about the new prop.

FYI - just because a certain component (i.e. propeller) comes standard on a certain new line of boat does not necessarily mean that it's the best component for that or any other application. Sometimes components are OEM because they meet an engineered spec, and sometimes they are OEM because one salesman is better than another. This I know first-hand, just sayin' . . .

I don't know which prop is going to be best for my boat. But I'm gonna find out!

Ptownkid
05-25-2011, 09:29 PM
FYI - just because a certain component (i.e. propeller) comes standard on a certain new line of boat does not necessarily mean that it's the best component for that or any other application. Sometimes components are OEM because they meet an engineered spec, and sometimes they are OEM because one salesman is better than another. This I know first-hand, just sayin'

Quoted for truth!!!

BTW, what prop did you get?

csuggs
05-25-2011, 09:59 PM
Acme 543 13x11.5 3-blade.

Randy_M
05-25-2011, 11:41 PM
Well after talking to at least 6 different suppliers of props and getting their recommendations, the decision was made to go with the OJ 4 blade 13x14. I would estimate that 80% recommended the 4 blade for the general usage we plan with this Saltare. We also bought from Discount Inboard Marine since they had the best price (after using coupons) and DIM offered the great option of trying the prop for about 30 days and if we weren't satisfied, returning the prop for another for only shipping charges. Since we only know how the original prop (14x13 3 blade) works on this boat (and it is damaged) we went with the recommendations of the majority of the suppliers and some of the people on this forum. We will update you once we have the prop and get the boat back in the water (probably next Tuesday after the crazy Memorial Day weekend).

Thanks for all the interest and suggestions.

csuggs
05-26-2011, 06:22 AM
Randy - sounds like you're doing the right thing. Good luck and let us know how satisfied you are. I'm glad you bought from skidim - good people! :)

Ptownkid
05-26-2011, 06:03 PM
If I remember right the Sunsport is listed as 2850lbs

DAFF
05-27-2011, 10:12 PM
What we need is a true full out prop shoot out. Get a bunch of Supra owners together in the north and everyone bring there props...

My comp has a originial non touched 13*13 3 blade and the new Susport is sporting a 4 blade... Perhaps some video and unbiast blindfolded results.