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Oddities & Rarities
December 18, 2018
Mercury Racing has been involved with several unique projects over the years. I thought you would find the products that evolved from those projects interesting to say the least.
Turbine Power
The experimental Mercury turbine outboard was built in alliance with Marine Turbine Technology (MTT) , LLC of Franklin, Louisiana. The engine featured a Rolls Royce Allison 250 series gas turbine (helicopter) engine mounted to a Mercury Racing 2.5 EFI Offshore mid section with a Sport Master or Torque Master gearcase.
The 320 h.p. engine was developed in the late 1990s in response to the then pending Department of Defense mandate that all gasoline be removed from ships by 2010. The turbine was light – weighing in at 200 pounds – about the weight of a 2-stroke 50 h.p. outboard. And it was multi-fuel compatible – with the ability to run on diesel, kerosene and JP4 jet fuel. MTT founder Ted McIntyre brought a turbine outboard powered landing craft to the 2001 Mercury Dealer Conference in Orlando, Florida. The boat stopped traffic every time the turbine spooled up to 51,000 RPM as it hauled awe-struck media and dealers around the lake. I went for a ride. I remember it was loud and I distinctly remember the fumes.
Multi-Fuel JP5
As time moved on and the military requirements became more defined – we set a course to develop a multi-fuel engine based on a conventional 2-stroke internal combustion engine design.
The OptiMax JP outboard was based on the 3.0 Liter V-6 OptiMax direct fuel injected, low emissions, 2-stroke engine. The 185 h.p. engine ran on JP5, JP8 and Commercial Jet-A fuels. The move to a multi-fuel engine based on existing consumer low-emissions 2-stroke technology is much more cost effective than alternative power sources.
2-Stroke Diesel
The OptiMax JP has since been replaced with our Diesel Spark Ignited (DSI) outboard. This exclusive spark ignited, direct fuel injected 2-stroke runs on ultra-low sulfur diesel fuel, which is readily available around the globe.
Small Block Bass
A unique application was the Super Scorpion 377 bass boat. The joint project between Mercury Racing and Chub Bryant, owner of Stroker Boats, was intended to show the world an alternative to outboards for bass boats. It was a great way to showcase our 6.2 Liter 377 sterndrive. The performance was very good. However, we just couldn’t change the minds of “clamp-on” outboard motor enthusiasts. With the popularity of outboards today – it’s hard to imagine a sterndrive bass boat would ever be considered.
Two Props. Two Speeds. Too Cool!
Here’s one of our more ambitious endeavors – the Mercury ProMax Deuce High. This one was a full-out engineering project. It was a combination of our fuel injected 2.5 Liter ProMax EFI powerhead and an advanced propulsion system. The mid section and gearcase were designed from a potpourri of sterndrive and outboard hydrodynamic engineering concepts and a very clever prop clutching device.
The most unique of its design innovations was its 2-speed automatic gearcase. The engine drove two, counter rotating props on the same axis — similar to the Mercury Racing Bravo Three XR sterndrive. Unlike the Bravo Three XR, the props were sequentially shifting: On initial acceleration, one prop would free-wheel while the other spooled up quickly. A computer controlled, hydraulic clutch system automatically engaged the second prop when the engine reached a preset torque. This enhanced hole shot, big-time!
Water pickups were built into a removable skeg. The fully surfacing gearcase was designed to run with the full torpedo above the water. The water running beneath the propeller hubs and torpedo improved propeller efficiency and eliminated torpedo drag.
The counter-rotating, fully surfacing props delivered unsurpassed boat speed and very good fuel efficiency; It also improved handling and stability because steering loads were neutrally balanced at all planing speeds. The boat was amazing crossing wakes or waves at odd angles – it just tracked like an arrow! Much easier to drive than a typical high performance bass boat.
Unfortunately, it couldn’t be sold at the price of an arrow – more like a cruise missile. The expensive hardware (two exotic stainless steel props, the stainless steel girdle/water pickup and the prop shaft/clutch mechanism) cost too much to go to market.
I hope you enjoyed this review of some of the more unique products developed by our accomplished engineering team.