3 Or 4 Blade SS

[Rangr90]

I have a 90' Ranger 361V bass boat with a 04' 150 HP Mercury Optimax.
which 3 and 4 blade SS prop would get me the best performance?
Prop brand & dia & pitch please.

Thanks
Rangr90

 

[211libwtfo]

I’ve been in a forum called offshore only and the resident prop guy there is ken something or another won’t be hard to find. Sorry to send ya out but that guy is awesome

 

[Sea Rider]

Buying blindly 3-4 blade props will be a costly experimentation, which current pop is installed right now and what's max wot rpm achieved as loaded to start with. Anyone can give a online prop answer, but on real world boating need to be tested on water as loaded and then going from there maximizing props to suit your particular boating needs.

It's near impossible to pretend buying a perfect prop on first try for any application, usually is dialed on second if not on third try, who said boating was a cheap water sport. LOL!!

Happy Boating

 

[Rangr90]

I bought the motor used and it didn't come with a prop.

 

[Sea Rider]

I bought the motor used and it didn't come with a prop.

OK, that's a different story. Dial with a prop calculator your starting point prop, can go from there maximizing other pitches, models, blades, etc to suit your boating requirements.

Happy Boating

 

[Faztbullet]

If I remember that hull should be 175 or 200hp. Do you have a jack plate? The 24 Trophy will be a good start....

 

[HT32BSX115]

I have a 90' Ranger 361V bass boat with a 04' 150 HP Mercury Optimax.
which 3 and 4 blade SS prop would get me the best performance?
Prop brand & dia & pitch please.

Thanks
Rangr90

Howdy,

Welcome aboard!

It's near impossible to pretend buying a perfect prop on first try for any application, usually is dialed on second if not on third try, who said boating was a cheap water sport. LOL!!

This is quite true!

One way to a "starting point" is to find an identical boat, similarly loaded with the same HP. If you cannot find one, go to the OEM manufacturer to determine what they recommend. This usually won't get you the perfect prop the first time, but you'll be close.

Once you're "close", you can then try different props (3 & 4 blade, aluminum and/or stainless) to refine.

Usually you cannot do this unless you go to a prop shop that will allow you to try different props.

You have to buy from them though!! Don't try different props from a shop and then buy somewhere else to get a better price!


Just about all the engine manufacturers recommend selecting a prop that will allow the engine to operate in the maximum recommended RPM range at WOT (Wide Open Throttle)

In general, you want a prop that will give you an RPM in the MAX range @ WOT for your engine (I.E. 5500-6000 etc) when you have the boat loaded (fuel, gear, people, dogs etc) where you'll operate most of the time.

If you want max performance, select a prop that gives you MAX RPM (or close to it.) But understand if you do this lightly loaded, It may be a little "doggy" when heavily loaded (if you ever load your boat to MAX gross wt)

OTOH, if you "prop" the boat for absolute MAX gross wt, (max RPM@WOT) and you always run around lightly loaded, you will be hitting the RPM limit at less than WOT (or the rev limiter if installed) at WOT

Since many people like to have spare props some will have props that will work for both

3 blade props will in general be best for all around use (with best top speed)

4 (or more) blade props will generally give better hole shot (and maybe slightly better fuel consumption at medium speeds) but not the fastest top speed. More blades (or blade area) in the water pretty much equates to more parasitic drag. reducing top speed

Make sure the engine is in good, tuned running condx, and you're using good fresh fuel before you try different props.

Cheers,


Rick

 

[Sea Rider]

The issue trying to duplicate someone else's identical combo, is that may encounter an owner who doesn't know a bit about re propping right an OB according to load or delaer installed a medium size prop pitch that doesn'y achieve say middle to max wot rpm range. As the saying goes : To each combo its own prop, as we have seen in many examples extra load and drag are serious killers to have in consideration.

Personally would preffer a Prop Selector to choose a Starter Prop and then go from there maximizing a top one or two for my boating needs specially if extra boaters will de added to my usual or fixed load.

Happy Boating

 

[dingbat]

First thing first, you have to decide what problem your trying to solve......diameter and pitch are only part of the equation as to how a prop performs on a particular boat.

You can put props of identical size on a boat and get two very different results depending on the props other attributes.

While wot and rpm figures are important, throwing out prop sizes without taking hull performance into consideration is futile....

 

[Texasmark]

All good verbiage. You have 2 "standard" requirements: Hole shot (getting out of the water and onto the water....on "plane") and max MPH which is what bass boats have to do.....it's in your blood, you can't help yourself.

Hole Shot:
4 Blades are better for the hole shot, in stainless steel, cupped (tips of blades bent forward slightly) progressive rake (blade does not come out of the hub like leaves on a daisy, rather fold back essentially making a tunnel of sorts). Having several large batteries at the transom, and in a lot of boats 30 gallons of fuel not far away, and just forward of that a couple of live wells full of water and topping that off with possibly some dead rise at the transom (hull not flat but formed into a V with a "pad" (water ski sized flat area in the rear keel area) on the bottom, makes for a hard to plane hull.

To assist in the task, most high performance props for the cause are "ported", which allows the prop to ventilate a controlled amount in the hole shot , taking some load off the engine as a shallow pitched prop would do, allowing the engine to rev. faster, developing it's HP faster and thus get you out and on top faster. The ports have to be sized to your requirement to get optimum results. Too large and you rev too high and have a sloppy shot. Too small and they are ineffective.

Top end:

Bass boats were made to run and they run on a "pad" as mentioned above. 60-65 MPH are common speeds for WOT operation. This is where the progressive pitch and rake come into play with the cupping for better grab, the ports have long since been sealed off by water pressure so they are out of the picture (as desired). The maximum efficiency of a propeller is 2 blades and it drops as the number of blades increases meaning that the 4 blade prop that helped you with a good hole shot is now working against you in getting your rig maxed out at WOT. So, like everything else there is a trade off.

----------------
What I would do is to go to a reputable prop shop and talk with a knowledgeable/experienced salesman. Guys with BBs spend a lot of time "tweaking" their rigs for max MPH....to out do their buddies in the club so props get "tuned" and prop shops do the tuning. Therefore there is a lot of input on what works and what doesn't.

A good shop will loan you a prop for testing after you discuss your aspirations and equipment. Your job is to take it, test it, and return it in the same condition as received. Tell the salesman what happened and follow his advice and pickup a different prop if necessary. Expect to pay more for their services but in the end you will get out of the deal cheaper than just shotgunning props and be happy with your purchase.

As my subscript suggests, get a seasoned "basser" to teach you proper engine trim and throttle techniques, aka boat handling for running your rig. Just a few minutes of tutoring from him can make a huge difference in your performance. I'd bring him onboard early in your prop selection process.......Heck, join a bass club!

As Sea Rider says, Happy Boating!

Mark

 

[Sea Rider]

Mark,

The provided overall prop explanation is excellent, but what if OP can't find a good prop shop that will lend props for testing along a reputable bass guru. Which way will be his staring point ?

Happy Boating

 

[Faztbullet]

Got to know how its set up first....whether owner want top end or is going to pull skiers sometimes. Motor mounting,height and use all come first.

 

[Texasmark]

Mark,

The provided overall prop explanation is excellent, but what if OP can't find a good prop shop that will lend props for testing along a reputable bass guru. Which way will be his staring point ?

Happy Boating

Go to a marina and see what others running similar boats are running and ask how it works, or go to a Ranger dealer if you have one and ask, or last, Google Ranger Boats and ask.

A SWAG: My current reference is a '96 sales brochure, standard 150's show 2:1 gear ratio and top out at 5600. I used to run 6000 regularly but will will use that. On a Pad Ranger (which I had) setup properly with the right prop, let's take 10% slip for a number. Go-Fast prop slip calculator says:

Gear ratio: 2:1
RPM: 5600
Pitch: 24 (Laser II, 141/4x24P, 3 blade)
Slip: 10%
Max MPH: 64 (this would be like a screw in wood, no slip)
Actual MPH: 58

If you were running light, had the boat setup right and all, and as a result you upped your RPMs to 6000 and at the better speed dropped your slip to 8% then Actual MPH would move on up to 63 mph.

However this number is for pristeen conditions which seldom exist where I boated. But it is an obtainable number if everything is in your favor, like the wind/waves to start with, smooth to a slight chop.....a few inches of wave height.

A better number is propping for 55 at 5600 and 12% slip which would put you in a 23P for 54 MPH, not hard to get with that boat and engine combination as I see it. This is more of what you would want for everyday fishing. If you are wanting to do water toys then you would want to drop down to a 21P in the Laser II design or something similar in amenities and keep your WOT RPMs in check when running light.