Do I have a better option? Prop Selection Question.

[mxzeatr]

My boat:
1987 Four Winns Horizon 190
150HP BlackMax XR2

90% of the time we are just out for a cruise, or headed to a 'spot' to hang out for the day. The other 10% we do have a skier, or maybe a tube battle going on. Again, the ski/tube is once maybe twice per year.

I have 2 different props, and I am unsure if I can compare the two realistically, but this is the info I have.

Prop 1.

Michigan Wheel-3 Blade Aluminum
14"x19p
5800rpm
45mph (gps)

This prop does a decent job, except with a boat load of people, or when trying to tube/ski. It just doesn't have the holeshot for it. When cruising around/running from lake to lake, it does do a nice job keeping the boat planed out going slower, and gives it the highest speed if/when needed.


Prop 2.

Michigan Wheel-3 Blade Stainless Steel
13.5"x17p
6200+rpm
45mph (GPS)

This prop has a great holeshot, but, when wanting to cruise at 22-26mph the boat doesn't feel like its 'out of the water' like it does with the 19p prop. It needs more throttle to keep it cruising, and the RPM's are higher throughout the range. However, since I enjoy the holeshot, I do leave this prop on the boat more often then not.


What I am looking for...

A prop that yeilds a 'decent' holeshot, fairly 'low' cruising speed, while still giving me a decent top end...Read, a mixture of the two above, without having to swap back and forth...

Am I looking for too much? I've heard that the 4 blade props will loose a bit of top end, but provide a good holeshot, and keep the boat up out of the water better, thus making it more efficent when cruising around? Might take a small hit in mph, or wouldn't matter for this boat?

I've found a 14"x18p 4 blade aluminum...Could this be the right prop for me? I'd prefer aluminum, I think they are decent props for non-performance type boats, plus, being budget wise, they are cheaper.

Thanks!

Here is a pic of my boat.

 

[steelespike]

Re: Do I have a better option? Prop Selection Question.

My info (not confirmed) says 1.78 gear ratio.The 19" is at 23% slip.Almost double of high normal.
That's assuming all is accurate.The 4 blade should lower slip Which "could actually improve speed".
It happens occasionally.A 4 blade should also improve hole shot,the ability to stay on plane with less throttle.
Also may handle better around the dock. This assumes the 4 blade makes 5800.The drop to 18" is supposed to help maintain rpm.

 

[mxzeatr]

Re: Do I have a better option? Prop Selection Question.

I am unsure what the ratio is in the lower end as well. I believe that the tach is accurate, and the speed readings were taken via GPS, I might have seen 47 on premium water conditions (little chop) and light load of fuel. That would reduce the slip a tiny bit.

If a guy were to buy a 4blade prop, are you suggesting going to an 18p? Leaving the diameter the same? Looks like the 4blades are 14.5" dia? The motor seems to be real strong, I couldn't believe it spun that heavy stainless 17p as good as it does. I thought I might be around 6000 rpm with that, but it'll spin it way higher if I'm not cautious with it...

 

[steelespike]

Re: Do I have a better option? Prop Selection Question.

If you look in the prop store and note pitch and size generally as pitch goes up diameter goes down.
usually adding a blade will reduce diameter. Not every prop but generally.
If you had a pontoon or a very heavy boat you might look for a larger diameter.
The weight of your ss prop doesn't affect the ability of the motor to spin it.
You would expect a ss to be more efficient and load the motor more but also it is a thinner more sophisticated design easier ro spin,it would likely affect the hull more creating more speed.
Generally a 2" pitch change will change rpm 300 to 400 when going to a different material things become more unpredictable.

 

[Philster]

Re: Do I have a better option? Prop Selection Question.

I would say an 18p, 4-blade maximum bow lifter SS prop is what you need. Something along the line of the Mercury Tempest. Maybe not that exact prop (if it is pricey), but if you research props, you need a maximum bow lifter with that V. Also, it has vents, which help hole shot.

No, it won't point the noise up!... but it will life that V hull out of the water. That's what bow lifter props do: Lift the V hull out of the water. You can google 'maximum bow lift prop' and consider your options. There is also the Bravo for outboards - another good prop for your hull.

.

 

[mxzeatr]

Re: Do I have a better option? Prop Selection Question.

If you look in the prop store and note pitch and size generally as pitch goes up diameter goes down.
usually adding a blade will reduce diameter. Not every prop but generally.
If you had a pontoon or a very heavy boat you might look for a larger diameter.
The weight of your ss prop doesn't affect the ability of the motor to spin it.
You would expect a ss to be more efficient and load the motor more but also it is a thinner more sophisticated design easier ro spin,it would likely affect the hull more creating more speed.
Generally a 2" pitch change will change rpm 300 to 400 when going to a different material things become more unpredictable.

Thanks steelespike! It seems most of the props I've been looking at that are 18p are still in the 14" dia class for my prop. I've been looking at alum since its cheaper, and the boat isn't a speed queen, and never will be!

I would say an 18p, 4-blade maximum bow lifter SS prop is what you need. Something along the line of the Mercury Tempest. Maybe not that exact prop (if it is pricey), but if you research props, you need a maximum bow lifter with that V. Also, it has vents, which help hole shot.

No, it won't point the noise up!... but it will life that V hull out of the water. That's what bow lifter props do: Lift the V hull out of the water. You can google 'maximum bow lift prop' and consider your options. There is also the Bravo for outboards - another good prop for your hull.

.

Hey Philster, your on Checkmate-boats right? You just ordered/picked up your boat if I remember that correctly? I lurk over there, been a checkmate fan for many many years, my user name is EricK. Was thinking about posing the question over there too.

How do the bow lifter prop's work for towing skiers/tubers/etc? Getting the V up out of the water better would definaltey help, I will take a look at selections, I appreciate the information!

 

[mxzeatr]

Re: Do I have a better option? Prop Selection Question.

No other opinions/suggestions?

 

[mxzeatr]

Re: Do I have a better option? Prop Selection Question.

Still pondering props...

I hope to get some GPS speed and RPM numbers to re-assure my memory from last summer this weekend. I'm thinking an 18p 4 blade would be the right choice for me.

 

[steelespike]

Re: Do I have a better option? Prop Selection Question.

Comparing it to the 19 the 18 makes sense.Should maintain rpm and should improve slip.
The 4 should keep the boat on plane easier at reduced throttle.
You also may notice better response around the dock as well.
You may want to investigate aluminum bow lifter props as well.

 

[Philster]

Re: Do I have a better option? Prop Selection Question.

Thanks steelespike! It seems most of the props I've been looking at that are 18p are still in the 14" dia class for my prop. I've been looking at alum since its cheaper, and the boat isn't a speed queen, and never will be!



Hey Philster, your on Checkmate-boats right? You just ordered/picked up your boat if I remember that correctly? I lurk over there, been a checkmate fan for many many years, my user name is EricK. Was thinking about posing the question over there too.

How do the bow lifter prop's work for towing skiers/tubers/etc? Getting the V up out of the water better would definaltey help, I will take a look at selections, I appreciate the information!

Dang - I must have snoozed past this thread somewhere! Sorry, man!

Yeah, same name over there on the Check site! That's me!

You are looking for alum, right? Michigan Wheel Vortex comes to mind. 18p. 4-blade Alum. Generally, performance and handling characteristics come with SS props. The real engineering goes into those props. Alum will be 'vanilla' or 'generic' and about all you can do is address RPMs. So, the 18p 4-blader would be good. So, you lose about 2 MPH but getting better everything -- not quite as dramatic as an SS prop though. But, Alum props now and then get some engineering:

http://boatpropellers.iboats.com/Me...S_992203_Propeller/309/671/?*******=598549205

^^Alum and has cupping and flared hub = Good! Now, you might want to consider a 17p, because cupping can steal RPM (100-150).

So, bow lifters props are for V-bottom boats. They don't point the bow up; it's just a way of distinguishing the props ability to get less wetted hull. Most props aimed towards V hulls will have this ability because they have a certain combination of rounded ears/cupping/raking/etc. I think that SS props are really the ones sporting the most advanced designs. Anything that works well with a given hull will pretty much make it do everything better, including towing people, because more advanced props will give more bite and lift, which makes planing better.

I have a 3B Tempest Plus, but I am torn over getting the 4B Trophy, which ain't cheap!

Sorry for missing this. I am usually all over threads that I post in!

 

[mxzeatr]

Re: Do I have a better option? Prop Selection Question.

Comparing it to the 19 the 18 makes sense.Should maintain rpm and should improve slip.
The 4 should keep the boat on plane easier at reduced throttle.
You also may notice better response around the dock as well.
You may want to investigate aluminum bow lifter props as well.

I haven't been able to see anything that says 'bow lifter prop' in aluminum. Maybe I don't know what I'm looking for, or just not looking at the right props.

Dang - I must have snoozed past this thread somewhere! Sorry, man!

Yeah, same name over there on the Check site! That's me!

You are looking for alum, right? Michigan Wheel Vortex comes to mind. 18p. 4-blade Alum. Generally, performance and handling characteristics come with SS props. The real engineering goes into those props. Alum will be 'vanilla' or 'generic' and about all you can do is address RPMs. So, the 18p 4-blader would be good. So, you lose about 2 MPH but getting better everything -- not quite as dramatic as an SS prop though. But, Alum props now and then get some engineering:

http://boatpropellers.iboats.com/Me...S_992203_Propeller/309/671/?*******=598549205

^^Alum and has cupping and flared hub = Good! Now, you might want to consider a 17p, because cupping can steal RPM (100-150).

So, bow lifters props are for V-bottom boats. They don't point the bow up; it's just a way of distinguishing the props ability to get less wetted hull. Most props aimed towards V hulls will have this ability because they have a certain combination of rounded ears/cupping/raking/etc. I think that SS props are really the ones sporting the most advanced designs. Anything that works well with a given hull will pretty much make it do everything better, including towing people, because more advanced props will give more bite and lift, which makes planing better.

I have a 3B Tempest Plus, but I am torn over getting the 4B Trophy, which ain't cheap!

Sorry for missing this. I am usually all over threads that I post in!

No problem in missing the post! I'm so 'wishy washy' on buying a prop anyways, that I'm unsure of what to do. I'm wondering how you tell if a prop is cupped or not? I've read all the FAQ's etc on it, but I guess I'm still unsure of what I am looking at. I really would like to stay alum, basically for an affordable upgrade. Basically trying to see if it will improve over the 2 choices that I have now you know? I'm not set on a 4-blade either, but I do like what I read about them, about around the dock, improved handling, holeshot, lower rpm to keep on plane, etc...Seems like it'd be a winner for a lot of our boating, without having to swap back and forth.

I plan to put the boat in the water this weekend, but fear I'll only have time to run it with one prop on my way over to the lift to cover it and let it sit for another couple weeks. Should I get some good solid data from the 19p since its aluminum and thats what I'd like to stick with? Its a Michigan Wheel prop, but unsure on the model.

BTW, your boat is my wife and I's dream boat. LOVE LOVE LOVE the 2400BRX 300xs combo!

 

[mxzeatr]

Re: Do I have a better option? Prop Selection Question.

OK. So after some more research and testing, I've found that indeed the boat runs better with the 19p prop. I'm spinning the 17p 6000 RPM's with over 1/4 throttle movement left, its too small it seems.

The numbers are here:

Lower unit is 2:1 (from doing a lot of research)
14x19p Alum
5900 rpm
44 mph

So it seems my slip isn't as bad as we once thought. Still thinking I can do better, pondering this prop right here, but I'm not sure if I should just be happy with it the way it is, and find a nice used 14x19 SS 3 blade?

http://www.ebay.com/itm/MERCURY-MER..._Accessories_Gear&hash=item1e6f148c44&vxp=mtr

 

[jimmbo]

Re: Do I have a better option? Prop Selection Question.

your motors' WOT rpm range is 5500-6000. You are right in the ballpark rpm wise. The 17 is a little small but will be an excellent prop for sking. Just be careful not to pull anybodys' arms out of their sockets.

Personally I swear by the Mercury Enertia. Great acceleration and good top end plus it has real grip on the water. With it the whole boat feels like it is riding higher out of the water, not just the bow. It does respond well to positive trim and can carry the bow out of the water too, if thats you thing