Selecting the Right Pitch

The RPM your engine runs at wide open throttle (WOT* click to learn more) is determined by the pitch of your propeller.  With too much pitch, the engine won't be able to turn the propeller in the proper RPM range.  Too little pitch and you could over-rev and possibly harm your motor.

Using a propeller that gives you the correct WOT RPM range will give you a better hole shot, better acceleration and top end, and improved fuel economy.  You will get the best performance out of your boat when you are running your engine in the correct RPM range.  

How do you select the correct pitch for your boat and motor combination?  First, ensure you have a working and accurate tachometer.  You will need to run your boat with your current prop at full throttle (without exceeding your engines recommended max rpm) and best trim angle with a normal load (see upcoming article about engine mount and trim angles).  At full throttle, note the RPM on your tachometer.  Compare this number to the WOT number for your engine.  

For example: If your engine WOT range is 4400 to 4800 RPM,  and your test run shows you are  turning 4100 RPM at max throttle, your engine is running outside of the manufacturers RPM range. 1 inch of pitch usually equals 200 RPM, so for this instance installing a propeller with 2 inches less pitch would increase your RPM to 4500 (200X2=400), which is now inside your WOT range. Remember, adding pitch reduces RPM, subtracting pitch adds RPM.

As another example: If your engine WOT range as specified by your manufacturer is 4400 to 4800 RPM,  and your test run shows you are turning 5000 RPM (do not run the engine higher than your manufacturer's maximum RPM for more than a few seconds), you need to add pitch to decrease your WOT RPM.  If you install a propeller with two inches more pitch, you may reduce your WOT RPM by 400 RPM (200X2=400).  With this new propeller installed, your boat test should now result in a WOT of 4600 RPM, which is now inside your recommended range.

Take note of your current propeller diameter and pitch.  From the examples above, you will need to purchase a new propeller that has a different pitch based on your test findings.  If you are currently running a 17” pitch propeller, and need to add 400 RPM, then you will need to purchase a 15” pitch propeller. If you need to subtract 400 rpm, then you would purchase a 19” propeller.  Different blade numbers, material and brands may affect the WOT RPM.

Your local Turning Point dealer has stock of a variety of propeller diameters, pitches, blade designs, and materials that will meet your needs.  For help determining the correct propeller for your boat and engine combination or locate your local dealer, consult the online Prop Wizard by Turning Point at www.turningpointpropellers.com. Prop Wizard is the only pitch calculating tool in the industry, and can help you get the most out of your boat's performance.

*Please also refer to “What does WOT Means” article.

Selecting the Right Pitch

By:  TP.  Engineering

Turning Point Propellers, Inc.Published:  2012-07-18

What is Propeller Pitch?

Propeller pitch is the theoretical forward movement of a propeller for one revolution, assuming that there is no prop slip. For example, a 21 pitch propeller will theoretically move 21 inches for every revolution. 

The second number listed in a propeller size is the pitch (Ex. 14 1/4” X 21”).

When selecting a propeller pitch for your boat, it is important that the propeller runs at the upper end of your engines wide-open-throttle RPM range. If you want your RPM's to increase, go down in pitch. To decrease RPM's, go up in pitch. As a general guide, for every 2" of pitch, RPM's will change approximately 400 RPM's. 

Related Articles:  What does WOT mean?

Selecting the Right Pitch

 

 

 

What is pitch?

By:  TP.  Engineering

Turning Point Propellers, Inc. 
Published:  2012-07-11

TURNING POINT PROPELLERS RELOCATES TO JACKSONVILLE, FLORIDA

Office operations in Chicago, including marketing, sales and engineering will shift to the new 3,000 sq. ft. office/lab/warehouse on July 1.  All product will continue to ship from its 75,000 sq. ft. warehouse facility in Chicago.

"Florida's warmer climate and heavy concentration of boat manufacturers facilitates a year-round product development cycle," said Ron Bailey, Turning Point Propellers VP of sales and marketing.  "This will result in faster introductions of industry-leading designs, such as our latest Hustler Four Blade propeller.

"We are updating our prototyping and engineering resources and capabilities at the same time in our design studio," he said.  Turning Point is pursuing R&D opportunities with nearby University of Florida and Florida State University engineering departments.

Turning Point celebrated its 15th anniversary in May.  A leading innovator, the company engineers, manufactures and markets aluminum and stainless steel props for outboards and sterndrives from 8-300+ hp.  It pioneered the interchangeable hub system and the use of squeeze casting manufacturing methods for superior propeller performance.

Turning Point Propellers, Inc.

11762 Marco Beach Dr., Suite 2

Jacksonville, FL  32224

Phone:  847-437-6800

Fax: 847-437-6868.  

Email:  sales@turningpointpropellers.com

Web site:  www.turningpointpropellers.com

Turning Point Propellers Relocates to Jacksonville, Florida

By:  TP.  Managemnt

Turning Point Propellers, Inc. 
Published:  2012-07-06

What does WOT mean?

WOT stands for Wide Open Throttle.  Each engine manufacturer will specify the range of RPM that the engine can run at wide open throttle and maximum trim angle.  You can find this information in your owner’s manual or on the manufacturers website.   It is important to select the correct propeller to run within the WOT RPM range, preferably at higher end of the range.

How do you select the correct pitch for your boat and motor combination?  First, you will need to run your boat with your current prop at full throttle and full trim with a normal load.  At full throttle, note the RPM on your tachometer.  Compare this number to the WOT number for your engine. Also note the pitch of your current prop.

You must have a working tach to determine the correct prop for your boat.  If you do not have a tachometer, or believe your tach is not functioning correctly, consult your marine dealer or mechanic to fix the issue before continuing.

Using a propeller that gives you the correct WOT range will give you a better hole shot, better acceleration and better top end.  You will get the best performance out of your boat when you are running in the correct RPM range.  

Please refer to Selecting the Right Pitch article on how to use WOT RPM information to select the correct pitch of propeller (coming soon 7/2012).

What does WOT mean?

By:  Phil S. & Ron B.

Turning Point Propellers, Inc.Published:  2012-06-27

Day On The Water - Check List Before You Head Out

It’s that time of year when we’re all excited to get the boat on the water.  All our gear packed in the car and we can't wait to launch the boat.   Now is the time to go through a check list of things before launching.

BEFORE YOU PUT THE BOAT IN THE WATER

1. The first thing to check is the drain plug.  Yes the one you never take out, but because it rained all the way home on the last trip, you removed it.  Make sure it is tight before launching the boat.
2. Next check the prop. ( For information on how to change a prop, see our upcoming “Prop Change Article” in Prop 101).  Remove it and look for fishing line that may be behind the thrust washer.  While you have the prop off check to make sure there are no bent blades, damage from bottom strikes, or very rough edges.  If anything looks out of place change the prop.  The propeller is the only thing that moves the boat.   A damaged prop will not only cost you a loss of performance and fuel economy, but can damage the prop shaft and bearings in your lower unit.
3. Carry a spare propeller and prop wrench.  It is usually cheaper to buy a propeller at home than to purchase one at the marina on a weekend! Spare cotter pin, nut, and pliers are good to have on hand.
4. If you have an Inboard/Outboard;Sterndrive, make sure to run the blower for at least five minutes before you start the engine.  That will flush out any gasoline fumes that could be in the bilge.

 

NOW WITH THE BOAT IN THE WATER

5. Now that your boat is in the water, check that the kill switch works correctly.  Start the engine and pull on the clip that engages the kill function.  If it does not stop your engine get the unit replaced before you go out on the water.  Replace the clip and attach the lanyard to your swim suit or life vest when you pull away from the dock.
6. Check the battery cables and battery switch if you have one.  Look for loose wires, corrosion and check any circuit breakers.  Fix them before you head out, or your battery may not start the boat after a few hours on the water listening to your favorite tunes!
7. Make sure you have a full tank of gas.  Use the “rule of threes”: one third of your gas to go to where you are going, one third to get back and one third as a safety cushion.  Check all fluid levels: engine, outboard oil, power or hydraulic steering, trim tab.
8. Make sure there are life vests and throw-able flotation cushions for everyone on the boat. Consult a USCG safety check list and local requirements for other recommended safety items. 

By taking a few minutes to go through a checklist you can have a safe and fun day on the water.

DAY ON THE WATER - CHECK LIST BEFORE YOU HEAD OUT 

By:  Phil Stephanuik

Turning Point Propellers, Inc.
Published:  2012-06-20

To Repair Or To Replace (Boat Propellers)

Props can take a beating in even the best conditions.  Churning sand, mud, floating debris, logs and rocks can bend, chip or crack blades.  Even minor nicks, dings or scratches that accumulate from normal wear-and-tear can rapidly degrade performance.  Running a damaged or bent propeller has the same effect as driving on worn or poorly inflated tires─you have less control, and performance and efficiency suffer.

           Worse yet, continuing to use a bent or cracked prop can damage the engine's gearcase.  A compromised propeller will not spin true, creating excessive vibration that can have devastating results. With this in mind, propellers should be inspected regularly for damage.  Spring commissioning and fall layup are great times for a close look.  Trailered boats can easily be examined prior to each trip.  Signs of severe wear, such as chipping or cracks on the blade tips or cracks along the blade joints, are easiest to spot.  Another important but less obvious item to inspect is the propeller's pitch, as the blade angles can become bent or offset over time.  If propeller blades seem out of alignment, it's best to have them inspected by a local prop specialist.

Apart from regular prop inspections, if while running the boat you hit something or tangle up in thick weeds, examine the prop as soon as possible.  If you heard it or felt it, damage is highly likely.  This is also why a spare prop should be an essential onboard piece of equipment.

When prop damage occurs, the question is whether to repair or replace.  Propeller repair can be expensive, especially on hard-to-weld stainless steel.  Blades that are ground down to remove bent or chipped edges create subtle changes in prop pitch and diameter that can degrade performance.  And, few prop shops can guarantee same-day service, especially in the heart of boating season.  This leaves you off the water.

However, if the damaged prop has a removable hub, the housing can instead be replaced for about the price of a repair.  Why repair a prop and contend with performance issues when a brand new one can be installed for a comparable price, putting you back on the water the same day?

There also are good reasons to replace an older propeller that is still in good condition.  Changes in hull design and the introduction of high horsepower outboards have led to radical new approaches to propeller design and manufacturing.  In addition, computer modeling has resulted in a better understanding of fluid dynamics and high-velocity water flow.  Advances such as variable rake and pitch blades, multiple geometries and new barrel designs have rendered older propellers obsolete in terms of hydrodynamic efficiency.

Choosing the appropriate propeller for a particular boat and motor is fairly simple.  The most important equation to understand is that less pitch means more rpm and more pitch means less rpm.  For peak performance, an engine should run at the upper end of the manufacturer's recommended rpm range, or WOT.  If more speed, handling and lift are desired, particular prop styles come into play.  The normal load on the boat, as well as whether the craft is usually used for fishing, watersports or cruising, also factors in prop selection.  Turning Point's online Prop Wizard tool helps you select the best prop for your boat/engine set-up.

To help keep your boat running its best, replacing a propeller is quick, easy and inexpensive for models with an interchangeable hub system.  Any damaged blade requires only that the housing be replaced, not the entire prop, saving hundreds of dollars over the years. 

To Repair Or To Replace

By:  Ron Bailey, VP Sales and Marketing

Turning Point Propellers, Inc.
Published:  2012-06-13

Also published in “Boating Sportsman” page 34.

Contact Turning Point Propellers,  847-437-6800; Fax: 847-437-6868.  sales@turningpointpropellers.com; www.turningpointpropellers.com

Turning Point Social Media Initiative Launches

We would like to announce the kick-off of Turning Point’s Social Media Program.  This new Program will launch June 6, 2012 on a variety of portals.  Visitors to the Turning Point web site, www.turningpointpropellers.com will notice a selector bar at the top right of the page that allows them to keep track of the developments of our company through their favorite sites.  At this time you can choose to follow or interact with us on LinkedIn®, Twitter®, Facebook®, Pinterest®, and Tumbler®.  As additional communication channels become available we will add them in future updates.

Every month we will be posting a variety of articles and test outcomes, building a propeller 101 database, and sharing general propulsion system musings from the experts in propeller design, manufacture, and marketing.  We expect to develop and have available  an extensive archive of propeller information over the next year or two, which will be of interest to any dealer, sales team member, or distributor partner.  We are striving to make the Turning Point site the go-to spot for all that is known about pleasure craft props and prop fitting.

To start on this journey with us, click on any of the following links below and start following us today:

        http://www.facebook.com/turningpointpropellers
        http://twitter.com/tpprops
        http://www.linkedin.com/in/turningpointpropellers
        http://www.pinterest.com/tpprops
        http://turningpointpropellers.tumblr.com/

We will be tweeting, blogging, and publishing a regular stream of cool stuff that will help you and our customers sell more, make more profit, and increase customer satisfaction.  Our goal at Turning Point is to help every dealer become a Prop Expert, by supplying the tools necessary to help them make educated and accurate propeller recommendations to the boating public.  This new program hopes to increase the level of expertise of our partners in the various  distribution and sales channels we participate in.   We look forward to sharing with you our vision of the future of boat propellers.

Ron Bailey, VP Sales and Marketing
Turning Point Propellers, Inc.