Smooth cornering props

[Dan_Cousin]

Its been my experience that given the same boat setup changing props can have a significant change in the boats ability to turn.

Some props like the 1400 series with a little cup turn really smooth and almost effortless. Other props, say 1600 series, V9 series, and various ABC props while faster in the straights seen to need more the get them around the corners. Given the same amount of rudder throw as with the 1400 series prop, the boat will make a wider arc with the other props and you have the "horse" the boat through the corner with more rudder throw.

Is it the pitch ratio that is causing this? Pitch Progresion? any other attribute?

:unsure:

 

[topfuel443]

Good question Dan, I also have noticed this... I am looking forward to the prop Guru's responses... As long as we can keep this out of the political debate area, it should be good.

 

[Joe Warren]

Martin Davis can answer the question..... Question is....... Will He? He could get a lot of of performance out of a prop 1400 & 1600 series. Always Ran smooth thru the corners, Launched easily & pulled Long & Hard down the stretch.... the Perfect Prop.....

 

[Buckshot]

Lift.

-Buck-

 

[Don Ferrette]

Lift.

-Buck-

Ahhhh............ we're getting warmer. Also remember cup reduces lift.............

 

[Terry Flynn]

Wouldn't the higher pitch also have something to do with it the prop is trying to push straight and you making it turn

 

[Marty Davis]

Martin Davis can answer the question..... Question is....... Will He? He could get a lot of of performance out of a prop 1400 & 1600 series. Always Ran smooth thru the corners, Launched easily & pulled Long & Hard down the stretch.... the Perfect Prop.....

ABSOLUTELY

The lift of the prop is the biggest factor, but there is also another BIG contributor. This is something that has other significant effects. The lift can be offset some by reducing the shaft angle to zero or even negative. The lift of the rear of the boat to higher level than say a 1400 series prop, makes the front of the boat wetter and thus makes the boat darty. The turn fin will work even better because the front sponsons are wetter. This can also be offset some by shallowing the strut and thus making the attitude of the rear of the boat the same as with a 1400 series prop.

Prop walk makes the boat try to turn without putting any rudder in the boat. What prop walk is is the prop working it's way up out of the water and then the tips trying to walk across the top of the water. Anything other than a super sharp prop will walk even more. The prop walk in fact makes the boat turn more since it tries to make the transom walk to the left and thus moves the front of the boat to the right.

I would say that the people I know who have mastered the higher lift, higher pitch props the best are Andy Brown (with MANY high lift/high pitch props) and Stu Barr (with the 1600 and V Series Props).

I personally like the 1400 series prop with some additional pitch in the largest diameter that is appropriate on a given boat. That allows me to run tight on the buoys even when the water gets rough. Some people like to run wider and faster, and that is another way to win. It is just not my personal style. There are also some new ABC props that work similar to the 1400 series like the 50x69, H7, etc, etc. These were props that Andy came up with while working at Tidewater and are still VERY good props. Notice that all my references are for a 20 hydro. The same thing happens on larger boats, but the diameter is more.

Hope this helps..... This kind of thread is good for everyone and stimulates good discussion.

Marty Davis

 

[Norm Doerr]

Marty;

If you would, can you explain how " prop weight" factors in :unsure: Does strut depth/angle and prop lifting characteristics play a role in this, (prop weight) :huh:

 

[Marty Davis]

Marty;

If you would, can you explain how " prop weight" factors in :unsure: Does strut depth/angle and prop lifting characteristics play a role in this, (prop weight) :huh:

Norm:

Prop weight does factor into the equation, BUT I am not versed enough on boats with rearward cg's to give useful information. Andy's boats have this characteristic and he would be the perfect person to answer your question.

As for the forward CG type boats, the amount of strut weight simply makes it easier or more difficult for the prop to lift the rear of the boat. Factor in shaft angle as an aid to this ability to lift and you have your answer. Each prop has characteristics which make them able to lift the rear easily, or not easily. For example, the X series Octura props have the ability to lift a LOT of strut weight, but not very high. The 1400 series have much less ability to lift a heavy strut, but lift higher than the X Series. The 1600 series and other ssimilar high lift props lift higher, but also do not have the ability to lift as much strut weight as the X Series. You will see many 1/8 Scale Hydros use X Series props for exactly this reason.

Marty Davis

 

[Mark Stein]

What are the reasons that a props lifts? specifically is it blade pitch, blade shape etc?

Mark

 

[Dan_Cousin]

Thanks Marty for the detailed answer.

I'd also like to hear some input from some of the other prop guys out there.

Andy?

Canto?

props4U?

Ferette?

Care the chine in?

 

[Don Ferrette]

Thanks Marty for the detailed answer.

I'd also like to hear some input from some of the other prop guys out there.

Andy?

Canto?

props4U?

Ferette?

Care the chine in?

Well Dan I have to be honest, once I figure out what I want in a prop I usually call Andy & have him make one. I also have gotten props from Mark Sholund who's best for me was an absolute killer sport 40 prop (X646/3). I could do props but for me it's easier to make a phone call, especially when I'm in the middle of a new project. Come to think of it, when am I not in the middle of a new project......

 

[henry velasco]

Thanks guy,s

I got a lot of info from this

Henry

 

[Chris Wood]

I started to do my own props about 5-6 yrs ago... one thing to look at is the roostertail.. is it flat or 100 ft in the air.. this will tell you if the prop is being effective..

also. there are different ways to cup a prop.. mine look weird but they seem to work.. AS ALLEN WADDLE ONCE SAID " YOUR PROP IS BENT" LOL!! YA I KNOW...

the tongue on the prop weither cut off or not can change things as well. lots to learn.. my head herts after working on them. not to mention bleeding fingers lol..

chris

 

[mark voorhies]

I started to do my own props about 5-6 yrs ago... one thing to look at is the roostertail.. is it flat or 100 ft in the air.. this will tell you if the prop is being effective..
also. there are different ways to cup a prop.. mine look weird but they seem to work.. AS ALLEN WADDLE ONCE SAID " YOUR PROP IS BENT" LOL!! YA I KNOW...

the tongue on the prop weither cut off or not can change things as well. lots to learn.. my head herts after working on them. not to mention bleeding fingers lol..

chris

Have never seen such awesome props as chris does, man I wish he sold um!

Sharp!! Thin!! Fast!!