While BBlades Professional Propeller Service of Princeton, Wis., is know primarily for its high-performance powerboat propeller tuning and demo programs, the company also offers drive blueprinting and has done so since its inception. The outfit offers blueprinting for an array of stern drives and outboard lowers including Mercury Racing No. 6 and NXT, Ilmor Indy, IMCO SCX and outboard Mercury SportMaster units.
“We’ve been doing it for years, but we’ve never really advertised it so not a lot of people know that we offer blueprinting,” said Brett Anderson, the company’s founder. “We’ve just been so heavily propeller oriented.”
Depending on the drive in question, the service ranges from $1,500 to $2,000 per gear case. Anderson says that most customers typically choose drive blueprinting in hope of finding more top speed, but there’s more to it than that. From the gear case itself to the skeg, nose cone and strut, the key is getting the “cleanest” water possible to the propeller, says Anderson, who adds that blueprinting also can improve a boat’s handling and overall performance characteristics.
“The big question is always, ‘How much speed am I going to gain?'” he explains. “And that could be as little as one-half mph to 5 mph. The biggest gains we see are when we correct deviations in the gear case. But we also pay a lot of attention to the skeg and nose cone. If you have an imperfection it can create a cavitation bubble. That disrupts the high-pressure side of the propeller, which causes prop slip to go up and efficiency go down. It’s all a matter of having the water travel cleanly to the propeller.”