Oddities & Rarities

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 Mercury turbine outboard featured a Rolls Royce Allison 250 series gas turbine engine. The engine was mounted on a Mercury Racing 2.5 EFI Offshore mid section with either a Sport Master (shown here) or Torque Master gearcase.

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. turbine outboard mounted on a Stroker bass boat.

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

The multi-fuel OptiMax JP outboard ran on JP5, Jp8 and Commercial Jet A fuels.

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 DSI (Diesel Spark Ignition) outboard was developed for military and light duty commercial patrol boat markets.

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

This experimental Stroker bass boat featured our 6.2 Liter Scorpion 377 sterndrive engine. Testing was done on the legendary Lake X.

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.

The Stroker bass boat project was a great way to showcase our compact, 377 horsepower, 6.2 Liter sterndrive.

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 Deuce High 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!

 

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.

Twin prop outboards were tried at Lake X in the early 1960s.

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.

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2 thoughts on “Oddities & Rarities”

  1. It seems I just keep getting into Mercury products deeper all the time, when I was young we always had Johnson/Evinrude then came a 9.8 Merc on my fishing boat, then a 75 Merc short shaft on a 300 pound GW Invader Go fast boat, that taught me about props/RPM. Today I run nothing but Mercury on all my existing boats and just bought a Donzi Black Hawk with a supercharged carburated 502 and a Bravo 1 shorty out the back running a 5 blade 29″ wheel. Its a clean sweep for me, ALL MERCURY!

    1. Karl,

      You are Wide Open! My first boat was a 10′ 1969 GW Invader with a modified Mark 55 Mercury and it is still in the family. Happy boating,

      Nick

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