Which prop for bow lift?

[layoutshooter]

I have a new Polar Kraft Outlander 2010CC. It has an Evinrude 115 E-Tec with a stock (garbage) prop. My hole shot is fair, top speed between 35-40MPH, which is fine and my RPM's are correct according to the book. It is an aluminum prop, 13.25X17.

The boat runs very flat when on plane at top speed. Too heavy on the bow. I know this is not a performance hull but it should have more air under it than I am getting. Aluminum is OK, lots of rocks and shallow water. SS will work.

Suggestions? Link to boat below:

Outlander V 2010 CC - Polar Kraft Boats

The CC is further up on the bow than most and I know that is a factor, even so, I should be getting more lift. I can trim it up at lower speeds, but not wide open.

 

[Texasmark]

Re: Which prop for bow lift?

If you must stay with alum. the only one that I know of with the asset you seek is the Turning Point Hustler, sold on the site. What you are looking for is "Rake". Rake is the bending of the blades toward the rear of the prop, which when used with proper trim creates a tube effect, like having a long tube with a thrust mechanism in it. When trimming such that the "tube" is lower in the front than in the rear, (trimmed out), the tube attempts to right itself....run horizontal, and in doing so forces the bow up.

I ran my first high rake prop on a Ranger with a pad hull back in '89. I didn't know then what I was experiencing, but it was like nothing I ever experienced before. Rather than the boat being "in" the water, it was "on" the water. When moving the trim out so that the prop could perform as intended, the bow came up (not like a hole shot, rather an on the water feeling) and with no change in throttle, the engine rpms increased dramatically and the boat speed increased likewise.

In rough water, of reasonable wave height and spacing, I found that I ran smoother "hooked up" on top of the water rather than running like I did with other boats working my way along, one wave at a time. What was cool was that in a lot of occasions, the transom would settle slightly as each peak was crossed and it was a very smooth "cushiony" ride.

Most of your SS on this site are raked. Take the two pictures above with a SS and alum prop. The SS is raked and the alum isn't. Notice how the blades are shaped and the shape is different.

HTH,
Mark

 

[Texasmark]

Re: Which prop for bow lift?

Here are a couple of shots of one of my bow lifting props. Notice how the blades are bent back and if you spin the prop you make a tube of sorts?

 

[layoutshooter]

Re: Which prop for bow lift?

I don't HAVE to stay with aluminum, my concern is wacking the prop in shallow water. We are often in only 2-3', or less, depending on the wind. We "lose the lake" in heavy winds and often have to come in with the engine trimmed up all the way, or push the boat in.

The prop also "blows out" at top end during turns.

I know it is aft rake I am looking for. Does the "Hustler" (or what ever it's new name is) have as much as some of the stainless props? Which of the stainless provide the best lift?

What about cupping?

On my old boat I switched from aluminum to a SST. The difference was amazing.

I DO have a shop who, for a few of course, go out with me and test several props on the boat. That is the only way to do it right that I know of. I am just looking for a few suggestions as to the best ones to start the tests with.

Thanks for all the help.

 

[jestor68]

Re: Which prop for bow lift?

Getting much bow lift on that boat is going to be iffy. The blow out in turns is more annoying than not getting the bow as high as you'd like.

Talk to your shop guy and get him to let you test a couple of BRP (Evinrude) SS props. The smallest Raker is the 18", while the Viper is available in 17", which may work better, depending upon what rpm you're getting now with the aluminum prop. With an rpm range of 5500-6000, you only have 500 rpm to play with and since you can expect a moderate drop in rpm when switching to a SS prop, the 17" Viper might be the better choice.

Both of these props are "bow lifters".

My next best recommendation; after the BRP props would be a Solas HR Titan 3 or 4 in 17" pitch. These are bow lifters as well.

That shop should be willing to let you test a couple (free) with the understanding that you're going to buy from him.

 

[layoutshooter]

Re: Which prop for bow lift?

am getting about 5000RPM at WOT with the stock prop. I am not expecting massive bow lift but right now I am 'plowing'. I know it is not a performance boat but I also know how a boat should ride. It has to come up some.

I can't seem to find the degree of rake on the discriptions on most props. I find that interesting. Do most people not research things that much?

I am also considering a 5" offset jack plate. First for the 'teeter totter' effect and second to get the prop into a little cleaner water.

I have looked at both the Rebel and the Viper, both are interesting. The Rebel only comes in a 13.5X18 as you stated. I was concerned about in increase in diameter and was not sure what the change in pitch would do. The Viper does seem to be my first choice to test.

I am hoping that the cupping on the prop will help with the blow outs.

I am looking forward to working with the prop guy here in town. I have talked with some people who have had work done by him and all seemed quite pleased with his work. All had repairs done, no prop testing.

Thanks for all the help.

 

[Texasmark]

Re: Which prop for bow lift?

I am hoping that the cupping on the prop will help with the blow outs.

That is exactly what cupping does and I guarantee you it works. The Hustler has everything but contain SS. I was reading up on it the other day and it has some special casting process whereby the alum is more dense and less prone to blade bending and hence allows for thinner blades making it that much more competitive with SS at 1/3 the price.

As I said, I just bought one one day for $99 here on iboats just to see if all their hype was true. It was!

Mark

 

[layoutshooter]

Re: Which prop for bow lift?

Thanks for the input! I too was looking at the Hustler. Seemed like a good possible alternative to SS.

 

[layoutshooter]

Re: Which prop for bow lift?

You said it lives up to the hype, what were you trying to accomplish with it? I assume I would stay with the same diameter and pitch with that prop?

 

[jestor68]

Re: Which prop for bow lift?

Both Turning Point and Solas use the "squeeze casting" process to cast their aluminum(only) props.

That's why these two companies make the best performing aluminum props around. Unfortunately, Turning point does not seem to offer their aluminum props in any of the larger diameters, like 15-15.5.

But no aluminum prop can be considered a bow lifter. They simply do not have the rake and cup that the SS props have. The Viper or HR Titan will kick any aluminum props butt in term of bow lift.

 

[jestor68]

Re: Which prop for bow lift?

am getting about 5000RPM at WOT with the stock prop.

With a rpm range of 5500-6000 rpm, what does that tell you?

 

[woody66912]

Re: Which prop for bow lift?

Make sure you don't have too much hook in the hull. Or have factory installed trim tabs?. If you have trim tabs they should extend out the back and be only like 1" x 5" long , if you do you can adjust them by bending them. You can check the hook by putting a straight edge on the hull, Hook is a indention along the the transom from port to starboard.

 

[layoutshooter]

Re: Which prop for bow lift?

With a rpm range of 5500-6000 rpm, what does that tell you?

Not running at proper RPM. Not getting trimmed right for one. Not sure, maybe a different diameter or pitch? Just learning this stuff, that is why I am here! LOL! Always find a resource that knows more.

 

[layoutshooter]

Re: Which prop for bow lift?

Make sure you don't have too much hook in the hull. Or have factory installed trim tabs?. If you have trim tabs they should extend out the back and be only like 1" x 5" long , if you do you can adjust them by bending them. You can check the hook by putting a straight edge on the hull, Hook is a indention along the the transom from port to starboard.

No trim tabs. New boat. Just starting to learn it. Not sure on the hook. Will check it next time I am home. On the road right now, truck driver.

 

[woody66912]

Re: Which prop for bow lift?

No trim tabs. New boat. Just starting to learn it. Not sure on the hook. Will check it next time I am home. On the road right now, truck driver.

10-4 good buddy, watch out for smokey, keep a eye on the bear in the air.

 

[layoutshooter]

Re: Which prop for bow lift?

Roger Dodger and KK. (Once a military radio op too! )

 

[jestor68]

Re: Which prop for bow lift?

Now we have a new ball game. I wish that I had known you were only getting 5000 rpm earlier.

Your 115 E-TEK IS RATED: 115 HP @ 5750 RPM. Needless to say at 5K rpm, you're not even developing full hp out of that motor.

You need to get that rpm up by at least 750 rpm if you want 115 hp. There is 150-200 rpm change per inch of pitch on average, so dropping to a 15" pitch will theoretically get you to about 5400 rpm; but if we can get that bow up a little, the rpm will increase more as well as speed. Enter the 15" Viper prop.

The real problem is simply the configuration of the boat....to much weight forward by design. I'm confident that a good 15" bow lifter type prop will make a difference; just not sure how much.

Since the boat is "new", is it too late to take it back and swap for one with a different configuration?

 

[layoutshooter]

Re: Which prop for bow lift?

Now we have a new ball game. I wish that I had known you were only getting 5000 rpm earlier.

Your 115 E-TEK IS RATED: 115 HP @ 5750 RPM. Needless to say at 5K rpm, you're not even developing full hp out of that motor.

You need to get that rpm up by at least 750 rpm. There is 150-200 rpm change per inch of pitch on average.

Up or down? What happens with SS? Does that change the RPM's? What about diameter?

 

[layoutshooter]

Re: Which prop for bow lift?

If I am reading things right I would have to move to a 13.25X13 instead of my 17?

 

[jestor68]

Re: Which prop for bow lift?

The new ball game refers as much to the boat design(layout) as it does prop issue.

The bow lifting 15" Viper will gain rpm by virtue of the pitch change and hopefully gain some more by getting the bow up some. It will definitely gain 400 rpm; how much more is the question.

A good aluminum prop will help with the holding in turns, but won't do much for bow lifting.

The catch 22 is that good bow lifter SS props are usually not available in pitches lower than X because they are not really design for boats like your boat.