I first learned Chris Fairchild won the 2011 SST 120 UIM/APBA World Championship Sunday, July 24, in a voice mail from my photographer buddy, Paul Kemiel. The championship consists of four heats of racing at the PNC Trenton Roar on the River outboard tunnel boat race, an annual event that takes place on the Detroit River in Trenton, Michigan. Chris won the event with an OptiMax 200XS SST race outboard, defeating a field of 15 boats, including defending SST 120 World Champion and fellow OptiMax competitor Jimmie Merleau.
Chris called me Monday. With a summer cold, he didn’t sound like a recently crowned champion. It was a while into our conversation before the topic of his accomplishment even came up – after a prompt from me. Read more
Continuing from Prop School….Part 1… Here, I will explain basic propeller terminology and fitment.
Diameter: In “prop speak,” diameter is the distance across a circle made by the blade tips as a propeller rotates. The proper diameter is determined by the power that is delivered to it and the resulting prop RPM.
Type of application is also a factor. How much propeller is in the water (partially surfaced vs fully submerged) plays a role in determining diameter: The more of the prop that is surfacing above the water, the larger the diameter needs to be (so what’s left under water can still push). On rare occasions, diameter may be physically limited by drive type or in close, staggered installations where tips can touch.
Within a specific propeller style, diameter is usually larger on slower boats and smaller on faster boats. Similarly, for engines with a lower maximum engine speed (or with more gear reduction), diameter will tend to be larger. Also, diameter typically decreases as propeller blade surface area increases (for the same engine power and RPM): a four bladed prop replacing a three blade of the same pitch will typically be smaller in diameter.
I’m Scott Reichow. I manage Mercury Racing’s propeller department (see my previous post, Bravo for Outboards? YES!). Working in performance boating is exciting: It’s fast paced. Propulsion systems and hull designs are in continual evolution. Our customers are generally astute, technically oriented and often quite colorful characters. We’re all performance freaks! We’re all continually learning. That’s what makes my job so much fun!
If you are like me, your first boating experiences were in lower horsepower boats used primarily for family recreation, fishing, skiing, wake boarding, or general cruising. And like me, your boating experiences and knowledge have evolved through time.
When working with high-end performance boats and experienced customers, one tends to assume people have basic product knowledge. However, a propeller is complicated. Because our backgrounds vary widely, our levels of understanding vary widely, too. So, we’ll revisit the basics and then dive deeper on propeller form, fit and function. Read more
Maybe this should be “Part 3 through # n” — since few things are odder or rarer than “one-offs” tried in pursuit of a speed record or race victory. Still, some stand tall above others in sheer audacity. Here are some outboards with an identity crisis.
Because of the high power to weight ratio of a Merc 2-stroke powerhead, it was inevitable that Mercury Racing’s Fred Hauenstein would lay some outboard engines down on their sides in his Arcadian Unlimted U-86 and go after inboard hydroplane competitors. Read more