4 blade prop?

F

ford_shooter

New Member
Jul 2, 2012
1
United States
Boat Info
1995 185BR
Engines
Mercruiser 4.3L w/ Alpha 1 Drive
I recently got a 1995 Sea Ray185 bowrider. I've had it out a few times in the last couple weeks. Runs great. All my buddies keeps telling me I should get a 4 blade prop for it. It currently has a 3 blade with a 21 pitch. Also has the 4.3L mercruiser in it. Is a 4 blade that much better? If so what pitch? Do i keep the same pitch at 21 or do something different?.
 
If your happy with it now why change it? A 4 blade will give you a better hole shot if you choose the right one. If you do go to a 4 blade I would drop pitch to 19 but watch out not to over rev the motor.
 
My prop was recently damaged, it was a 14x19p stock 3 blade. The guy at the prop shop suggested a larger diameter prop with less pitch for my particular needs. My boat is an 88 18' bow rider with a 175hp 4.3L. It was lazy out of the hole and had crazy bow rise trying to get on plane. I got a 15.5x18p 3 blade Quicksilver Black Diamond. The new prop pops the boat up quick with minimal bow rise. The prop guy suggested the 3 blade over a 4 blade so I could keep my top end speed, my boat will run 45 mph @ 4600. This thing really moves some water too, maneuvering at the dock is much more immediate when you click it in gear. I would like to try a 4 blade if I can find a deal on one, but I'm happy with this one so far.
Travis..

EDIT; my boat was originally spec'd with a 13.75x21 prop according to the sea ray spec sheet and it had a 14x19 when I got it. Even though I really like my new prop so far, I'm going to compare it to my 14x19 after it's repaired and to a 13.75x21 that I picked up used to see how they stack up to each other.
 
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Shooter....Welcome aboard...............woohoo, post #1
Get your buddies to buy you the prop......
The hard part about a prop change is getting the right one. There are so many to pick from, and each one does something different. And then you throw in the boat variables, how and what you use the boat for, etc., etc.
See if there are any places around that have demo props. That way you can try them out.
There's nothing worse than spending $200-400, and find out later it doesn't work any better than what you already have.
 
ford_shooter said:
I recently got a 1995 Sea Ray185 bowrider. I've had it out a few times in the last couple weeks. Runs great. All my buddies keeps telling me I should get a 4 blade prop for it. It currently has a 3 blade with a 21 pitch. Also has the 4.3L mercruiser in it. Is a 4 blade that much better? If so what pitch? Do i keep the same pitch at 21 or do something different?.
Click to expand...

if your going to do any puling-water sports or haul a boat full of peeps and gear, the 4 blade will get you up quick and not cost to much top end. i like a 4 blade for the lift getting on plane.

i found you can drop an inch of the diameter or a degree of pitch and end up close to the same as your 3 blade

there are some fairly inexpensive aluminum props you can try that won't break the bank. i did some aplo props when i still had the alpha drive and at that time they were in the $125 to 140 or so range
 
Best reply ever! Get your own boat
icon12.png
 
[FONT=Tahoma, Calibri, Verdana, Geneva, sans-serif]Hey Shooter

I would not bother with the 4 blade but go straight to a 5 blade prop. Specifically the Mercury High Five or save yourself $100 and get the Quicksilver QST 5 which is the same prop just without the vent holes which you don't need on a stern drive anyway. Honestly the difference is like night vs day. I will say that it is the best money you will ever spend on your boat. I changed from a S/S Mercury Vengeance 3 blade to the High Five on my 185 SP with 4.3 MPI and would never go back to the 3 blade.

If you are getting up around the maximum WOT rpm of 4800 for your 4.3 then go with the 21" pitch, however if your max rpm is down around 4400 to 4500 then go with the 19" pitch. The only downside is that you might lose 2 to 3 Mph off your top speed.

I guarantee that you will not be sorry if you follow this advice.

Cheers for now![/FONT]
 
I'd agree with the last post. Had the stock Al prop on my 175 sport when I bought it. Luckily for me I hit a submerged object. (Didn't think so at the time). Did a lot of reading and speaking to prop specialists and then managed to get my hands on a high 5 (blade). Wow

Hole shot is excellent, gets up out of the water almost immediately.

Happy now and won't look back.


Sent from my HTC One X using Tapatalk
 
Mikeyf said:
I'd agree with the last post. Had the stock Al prop on my 175 sport when I bought it. Luckily for me I hit a submerged object. (Didn't think so at the time). Did a lot of reading and speaking to prop specialists and then managed to get my hands on a high 5 (blade). Wow

Hole shot is excellent, gets up out of the water almost immediately.

Happy now and won't look back.


Sent from my HTC One X using Tapatalk
Click to expand...
Hmmm. See the posts below. So we have the same boat/year/engine with the same prop with two entirely different results. Anyone have a theory as to the differences?

http://clubsearay.com/showthread.php/43869-What-prop-to-use-for-a-175?p=487238&highlight=#post487238

http://clubsearay.com/showthread.php/43869-What-prop-to-use-for-a-175?p=487249#post487249
 
Ok here is more in the confusion. This was before the 4 blade props were available. When I had my 1989 Sunbird cuddy cabin, it had the same engine, 4.3L v6 with an OMC Cobra outdrive. I had 3 blade props from 15, 17, 19, and 21 pitch props. When I was pulling skiers, I would use the 17 pitch prop. Good for under a load like pulling skiers. The 19 and 21 pitch depended on what I was doing. If I was by myself or with 1 person, I would use the 21 pitch for speed. If I had more than 3 people in the boat, I would put the 19 pitch on to get out of the hole.

I carried all four on the boat and would swap them out as needed. The 21 pitch prop, coming back from Block Island in 2 foot seas, I was clocked at 42 @ 4k and still had more to go. I was by myself so there was no weight in the boat. On the CT river flat water, I was clocked at 58 mph @ 4600 RPM.

Each boat is different, the hull design, engine, out drive can create variances between output. I always used the aluminum props since it would save the outdrive shafts if you struck something. At the time, the props were around $125 each. So it was not a big investment and if I did strike something, it was between 30 & 45 to repair depending on the damage.
 
new to forum, bought a 2012 190 searay sport it came with a 14.25x21 pitch vengence 3 blade stainless prop. I did not like how long it took out of the hole. my old boat was a ls2000 yamaha jet boat 270 H.P. and planed out FAST. I got rid of it and got the searay due to weeds on our lake. I switched the prop to a 14x20 4 blade aluminum and hole shot icreased dramatically. I did lose about 2 MPH but who cares. I liked it so much I ordered a stainless thinking a stainless has less flex it might even be better yet. I can keep a plane at lower speeds with no problems. My questions for you guys that are running 5 blade stainless will the hole shot be even better than the 4 blade and will I give up top end speed.
 
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I have the 4.3 220 hp 190 sport with the pollution garbage on it alpha 1 drive 14x20 4 blade prop what will a 5 blade do for me, holeshot and top end speed effect. thanks
 
[FONT=Tahoma, Calibri, Verdana, Geneva, sans-serif]
boatnik1 said:
I have the 4.3 220 hp 190 sport with the pollution garbage on it alpha 1 drive 14x20 4 blade prop what will a 5 blade do for me, holeshot and top end speed effect. thanks
Click to expand...

G'day Boatnik

In answer to your questions, here is my take on it.

The 5 blade props (High 5 or QST 5) only come in 19P or 21P pitch so it would depend on which one you decided to run with. The 19P would definitely have even better and smoother hole shot but if you run light you will be bumping your rev limiter at times at WOT but I think this would top out similar in mph to your 14x20 alu 4 blade. If you do a lot of high speed light running then you may want to go for the 21P which I think would accelerate similar to your 4 blade but be maybe 2-3 mph faster on top end.

Another benefit of the 5 blades is that they really hang on in turns and are almost impossible to blow out or cavitate. If you do a lot of tow sports this can be just as important as hole shot in your all round boating day. Some people seem to forget this very important aspect. You can also trim the drive right up to its trim limit and they will not blow out either.

If you like your current setup, maybe try and borrow a 5 blade to try first before you commit the funds.

Cheers.[/FONT]
 
the four blade stainless 14x20 pitch is coming in today. I will post gps speed and rpm WOT. thanks for the info cubee.
 
Last year I switched from a 3 blade aluminum 14.25 x 21 to a stainless 14.125 X 19 260 V8 / Alpha 1 - 210 Seville MC

Aluminum 3 blade prop - 1,000 rpm (no wake speed) 3.3 mph 3,500 rpm - 25 mph and topped out 4,400 rpm 40 mph - Very slow out of the hole (I'm guessing 10+ seconds to get on plane)

Stainless 4 blade prop - 1,000 rpm (no wake speed) 4.6 mph 3,300 rpm - 25 mph and topped out 4,500 rpm 41 mph - Jumps out of the hole (I'm guessing 5 seconds to get on plane)

All speeds are per the GPS

All in all I am EXTREMELY happy with making this swap, It's like I have a new boat. - I see no down side in this case. I know this will not be the same result for everyone but I thought some would be interested in the information.

BTW - I used a Solas Rubex and have had no issues with it.

LK​
 
installed stainless 14x20 pitch 4 blade prop. With just me in the boat WOT hit 52 mph at 4350 rpm. hole shot was alot better than the same prop in aluminum but for some reason rpms dropped by 100, I'm thinking the flex in aluminum had something to due with that. I would like to be around 4600to 4700 rpms. Just wondering if a 5 blade 14x19 stainless would achieve this or would I jump from 4350 rpms to over 4800 and hit the over rev limit. Would love to find someone in Wisconsin where I could try it before I by it. Any suggestions would be great.
 
Your numbers are wonkey, no way you are going 52 while only turning 4350. Are you using GPS or Radar? You are lugging the engine if those are your actual readings.
boatnik1 said:
installed stainless 14x20 pitch 4 blade prop. With just me in the boat WOT hit 52 mph at 4350 rpm. hole shot was alot better than the same prop in aluminum but for some reason rpms dropped by 100, I'm thinking the flex in aluminum had something to due with that. I would like to be around 4600to 4700 rpms. Just wondering if a 5 blade 14x19 stainless would achieve this or would I jump from 4350 rpms to over 4800 and hit the over rev limit. Would love to find someone in Wisconsin where I could try it before I by it. Any suggestions would be great.
Click to expand...
 
G'day Boatnik

A couple of points.

1. What brand and model prop is the new SS 14x20 four blade?
2. At 4,350 rpm you are over propped and lugging the motor especially as you were running light with only one up.
3. Based on your numbers if you want to be at 4600 to 4700 rpm running light you will definitely need the 21P High 5 or QST 5 prop. I can hit over 5,000 rpm with 5 people in the boat with a 19P and my hull is the same as yours. Just the deck is different on the 190SP.

Cheers.
 
boatnik1,

I am curious where you got your boat, I have the same boat from MarineMax and it came with a 13.75-21 . What kind of prop did you get with the 14x20 stainless. I agree hole shot is a little slow, but trimmed all the way down I can keep planed out slightly under 20 with current prop.
 
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