Hi-Performance Boat Operation – Part 1: Introduction

It’s boat show season – the perfect time of year to check out the latest performance boats and Mercury Racing propulsion. For those of you who are about to purchase your first performance hull, congratulations!

With Winter in full swing, now is the time to review the basics of high-performance boat operation to ensure you and your passengers have safe experiences out on the water.  We include a Guide to Hi-Performance Boat Operation with every engine we ship. We encourage new and current owners to review the book and then take in-boat driving lessons from your local high-performance dealer or boat builder.

Our operation guide is packed with general performance boating information, including  propellers, hull types and overall boat performance. Let’s first review the various performance-boat hull configurations.

Vee-Bottom

Project 1080, Florida Powerboat Club’s official pace boat is a year 2000 Cigarette 38 Top Gun with a traditional vee bottom hull.

The traditional vee-bottom is the most common hull design. It offers good speed and a softer ride, especially in rough water. The softness of the ride depends on the angle of the “V” (called deadrise), radius of the keel line and the use of strakes.

If your boating is mostly in larger bodies of water such as the Great Lakes or open seas, you may want to consider a boat with this hull type.

This Outerlimits race boat features the stepped vee-bottom hull design.

The most recent change in this design over the past decade has been the incorporation of strategically placed notches or steps in the hull. The steps create air bubbles, raising the hull off the water on a drag-reducing cushion.

Some high performance hulls such as Allison feature a vee-bottom with a pad at the rear of the hull. The boat is designed to run up on the pad, minimizing drag for maximized speed and performance.

Some vee-bottom hulls feature a small flat area toward the rear of the keel called a pad. Similar to steps, the pad reduces the wetted surface area the hull runs on, increasing top speed with minimal effect on the ride quality. Mercury Racing offers a full array of outboard and sterndrive propulsion options for the vee-bottom boater.

 Tunnel

Outboard tunnel boats are the fastest-turning race vehicles on earth. The sharp, 90-degree transfer where the tunnel sides meet the bottom of the sponsons helps the boat settle in the water as it enters a turn.

F1H20 competitor Thani Al Qemzi slams his DAC tunnel boat through a turn at the 2018 Grand Prix of Sharjah race event.

The submerged sponsons make the boat turn as if it were on rails. It is common for drivers to experience 4.5 to 5Gs as they enter a turn at 120 mph and come out at 90+ mph. Obviously, only experienced racers should consider this type of hull.

 Catamaran

I like to refer to catamarans (or cats as they are often called) as tunnel boats on steroids. The design principal is similar. The boat rides on two sponsons or hulls separated by a tunnel. Air entering the tunnel generates lift as speed increases. The wetted surfaces and hull drag are reduced, for enhanced speed and ride quality. This design is not for the novice operator.

Catamaran boats ride on two sponsons or hulls separated by a tunnel. Air entering the tunnel generates lift as speed increases. The wetted surfaces and hull drag are reduced, for enhanced speed and ride quality.

The air entrapment hull is sensitive to engine trim, wind, and water conditions. In general, they produce a smoother and faster ride over a vee-bottom in calm to mild chop. The vee bottom is king in rough water.

The fastest recreational cats on the water today are powered by the venerable dual calibration 1550 sterndrive. The V8 4.6L 300R FourStroke is a popular choice for those who choose outboard power for entry into the cat experience.

In Hi-Performance Boat Operation – Part 2: Rigging Fit & Function, I will review the important things to consider when preparing your new Mercury Racing outboard – or sterndrive-powered boat for the upcoming season.

 

 

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Project 1080: Start Me Up

Stu Jones and Pat Sullivan catch some air as they sea trial Project 1080 for the first time. The Resto Mod Cigarette 38 Top Gun is the result of a nine month restoration of the legacy hull.

Florida Powerboat Club founder Stu Jones and Pat Sullivan – owner of the Mercury Racing dealership Performance Marine Trading tested FPC’s official pace boat for the first time on Wednesday. The freshly restored Cigarette 38 Top Gun features modern Mercury Racing hardware including 540 sterndrive engine packages with Integrated Transom Systems, Bravo One XR drives, Mercury Racing Bravo I Propellers and K-Plane trim tabs.  Digital Zero Effort Controls transfer driver intent to the twin 540 powerhouses.

One of the many custom upgrade made to the Cigarette is the addition of non skid SeaDek material to the deck.

The sea trial was the culmination of a project that involved stripping the 2000 model year boat to an empty shell, and updating all aspects of the legendary hull from bow to stern in form, fit and function.

Stu was anxious to share his first-time experience in the Resto Mod Cigarette with us.

“It was an amazing experience, given how the project evolved from a a simple repower to a complete restoration. It is amazing how it turned out. I honestly felt like I was driving an entirely new boat,” said Stu.

Installation of the 540 sterndrives and all rigging was handled by  Pat Sullivan and his crew at Performance Marine Trading.

The epic vee-bottom handled the ocean swells with ease. The durable 280S K-Plane trim tabs worked like a charm.

Stu handed over the helm to Pat, a former offshore racer for the initial shake down cruise. Pat eased the Zero Effort controls forward as the 540s quickly brought the Cigarette on plane. The epic vee-bottom handled the ocean swells with ease.

Race-proven Bravo I XR sterndrives transfer the 540 power to the water.

Pat said, “Stu you really have a great package here. The switch from mechanical to digital controls is like night and day. There is no comparison. And beauty of the new power is you don’t really have to worry about anything. These engines are so reliable, you just push the throttles and go.”

The Project 1080 Cigarette will make it’s pace boat debut this weekend at FPC’s Winter Poker Run to the Florida Keys, the first run for the 2019 season.The durable 280S K-Plane trim tabs worked like a charm. Both Pat and Stu grew an appreciation for the intuitive design of the VesselView 703 touch screen monitor as well. The replication of vital engine data on the larger Garmin display was easy on the eyes, providing a constant view of vital functions throughout their 20-minute journey.

Pat and Stu will return to dial-in props to take full advantage of the 540s’ 4800-5400 operating rpm range.

The Project 1080 Cigarette will make it’s pace boat debut this weekend at FPC’s Winter Poker Run to the Florida Keys, the first run for the 2019 season.

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Prop School – Part 4: Blade Cup

Continuing from Prop School…Part 3. Here I will explain everything you need to know about Blade Cup.

An illustration of cup added to the trailing edge of a typical through hub exhaust prop.

Cup is a curl formed or cast into the trailing edge of a propeller blade.  When done correctly, the face of a cupped prop blade is completely concave.

The first three-blade aluminum props for MerCruiser powered boats featured flat blades, with 15-degree rake. The heavy, deep-vee hull ran best with the drive trimmed up (raising the bow, reducing the wetted surface, and increasing hull efficiency). We got our first experience with cupped, 3-blade aluminum props in the mid ’70s. We immediately realized greater top-end speeds. We also noticed the engine didn’t work as hard. The cupped props were more efficient. Our measurement? The paint was still on the blades at the end the season. Cavitation burns, mostly from abusive teenage kids over trimming dad’s boat, would burn away the paint. The cupped prop definitely made  a difference.

Location. Location. Location.

Originally, cupping was done to gain similar benefits as you get from progressive pitch or higher blade rake. In fact, cupping reduces full-throttle engine speed 150-300 RPM below the same pitch prop with no cup. The location of cup on the blade determines the affect it has on performance. When the cupped area intersects pitch lines, pitch increases. Cupping in this area will reduce engine RPM.  Cupping can also prevent prop cavitation or blow out.   Blade rake can be increased when the cup intersects the rake lines. Slip is a measurement of propeller efficiency as it turns through the water, the normal range is 10-15%. Most racing and performance boats slip can be as low as 5-7% where as performance vee and step vee bottom boats with high X dimension (outboard engines or sterndrives mounted high) can see slip as high as 20-22% at WOT

Cleaver Cup.

All Mercury Racing propellers spend time on the grinding wheel.

Adjusting cup on cleaver-style propellers is more difficult. The trailing edge is very thick and runs straight out on the rake line. Pitch can be altered some by grinding away some of the cup. Rake may also be altered slightly.  The rake can be reduced by decreasing the cup near the tip of the blade. Rake can be increased by reducing the cup near the prop hub. Remember that any change in cup affects engine RPM. The Bravo I propeller family is a good example of how cup changes RPM and the attitude of the boat I will discuss blade configurations and factors that effect propeller efficiency in Prop School – Part 5.

 

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300R vs 300XS: And the Winner Is?

The business end of 112 mph!

I recently wrote a feature post on Liberator Boats of Florida and their initial experience with our new 4.6L V8 300R FourStroke outboard. I elected to feature Liberator as company owner Randy Corson had just received his first 300R in June. Randy has extensive experience with our V6 300XS two-stroke. I was anxious to get his feedback regarding our new engine and how it compared  with the 300XS it replaced.

Randy provided some initial performance numbers and then compared them with his archival 300XS data:

The 300R Sport Master gearcase features a 5.44 inch diameter torpedo for enhanced durability. The larger case is needed to handle 40% increase in bottom-end torque produced by the 4.6L V8 FourStroke engine.

Both engines featured the Sport Master gearcase. The 300XS had a 1.62:1 gear ratio. The 300R had a 1.75:1 gear ratio.  Due to the gear ratio difference, the 300XS ran a 32-inch pitch propeller. The 300R ran a 34-inch pitch prop. The bare hull weight of the 300XS hull is 940 pounds. Randy said it is the fastest 300XS powered 21-foot Liberator he has ever had.  The bare hull weight of the 300R boat was 1063 pounds.

The CNC outboard cleaver propeller.

“We saw  1.5 to 2 mph faster top-end speeds with the 300R compared to the 300XS with comparable props. At the time, the 300R topped out at 106 mph; that’s 5-6 mph faster than the 300XS when running a 15-1/4-inch diameter – 34-inch pitch Mercury Racing 5-blade CNC outboard cleaver.

Randy ran the CNC cleaver again on Christmas Day and was blown away by the performance – a top speed of 112 mph!

While the top-speed difference is impressive, acceleration is where the 300R really shines. The 300XS accelerates from 40-100 mph in 25 seconds. The 300R boat catapults from 40-100 in 18 seconds! The big difference can be attributed to a 44% advantage in displacement (4.6L vs 3.2L) the 300R has over the 300XS. That results in a 40% increase in bottom-end torque.

While the top-speed difference is impressive, acceleration is where the 300R really shines. The 300XS accelerates from 40-100 mph in 25 seconds. The 300R boat catapults from 40-100 in 18 seconds! The big difference can be attributed to a 44% advantage in displacement (4.6L vs 3.2L) the 300R has over the 300XS. That results in a 40% increase in bottom-end torque.

Hole shot acceleration is exhilarating as well. From 0-20 mph, the 300R is 25% quicker than the 300XS. Mercury’s proprietary transient spark calibration boosts torque by as much as 7% by optimizing spark timing and fueling to assist in superior hole shot performance.

We are excited to see the performance gains people are experiencing with our new 300R in both single and multi-engine applications.

 

 

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