Recreational Boat Building Industry Engines Folder

Recreational Boat Building Industry

Engine Development

This page will be covering developments in engines only. You will want to watch the Fuel, Lubes, & Oils Folder for fuel developments and the Regulations desk for emissions and noise regulations. We will not be covering normal production engines. We will be covering breaking developments in engine design or major development with existing engines. At the bottom of the page we discuss some of the basic differences in marine and automotive engine applications.

Discussion of Links

Be sure and look at the Engines section of the Other Useful Links Page. It includes links to many types of engines in development.

Discussion of Other Areas of the Site

The Folder has an interesting discussion in it about the "Ultimate Engine" as seen by many boaters.

You might want to watch the Patent Folder and the Technology Folder (especially the Product Technology Page).

One of our own "Invention" engines is posted in the Inventions & Inventors Folder on the RBBI Inventions Page.

Miscellaneous Thoughts and Information

Auto Makers Race to Sell Cars Powered by Fuel Cells

The 15 March 1999 Wall Street Journal included a major article on the automotive use of fuel cells.

Toyota's Hybrid Propulsion System

December 10 1997
Toyota's new Prius automobile uses a hybrid Propulsion system (engine and battery). We have been unsuccesfully trying to call it to the attention of the boating industry before they begin to see it in Toyota boats.

We have created a Toyota Hybrid Propulsion Prius Car Page which contains several articles about the technology.

New Cummins Prototype - Engine Development Facility

The December 1996 issue of Consulting-Specifying Engineer has a great 4 page article, "A Research Facility Driven to Succeed" on pages 38-41 describing numerous features of this new "top notch" engine testing facility. We will try to post some more information on it soon but thought some of you might want to "read ahead".

Toyota Low Cost Engine

The following two articles cover the actual December 96 announcement of the new low cost engine. The engine is to have 1/3 fewer parts and costs 1/3 less. The November 96 coverage was a bit if a "leak". The actual announcement appears to have been significantly downplayed as the only two references we found were quite well hidden (ever hear of the Lubbock Avalanche-Journal?). Toyota Japan has actually removed the entire month of December 96 from their press release coverage on their web site and none of the automotive industry sources appear to have covered it. These two articles are so close you may think they are identical, but each has a few comments not in the other. The first one also has some additional coverage of their direct injection efforts.

The following two articles cover the industry "buzz" that occured when Toyota "leaked" information about a pending announcement of a new low cost engine with fewer parts at a 8 November 1996 media reception.

  • Here is an update on the low cost engine situation from the Oct 31, 1997 Wall Street Journal. "Toyota Introduces New Engine in U.S. That is Much Lighter, Cheaper to Make".

    Russian Low Emision Engines

    Russia is developing some low emission engines. They include an axial engine that automatically changes piston stroke depending upon demand in gas and diesel versions. We have a file of information on them from the Technology Access web site.

    Background Info About Marine Engine Applications
    Basic Differences in Marine and Automotive Engines

    For those not greatly familiar with marine engine applications we will provide a few comments about marine engine applications and how they differ from other applications of similar engines.

    Duty Cycle - Automotive engines tend to spend most of their life in the low to mid rpm and are rarely ran at WOT (Wide Open Throttle). Many boat engines spend a lot of time at WOT. On the other hand, some fishing boat engines spend a lot of time at low rpm in a trolling mode. Boat tend to run up and down through the RPM range many more times than automobiles during the same operating time.

    Life Expectancy - Todays automotive engines are expected to go 100,000 miles with very minimal problems. Most recreational boat applications receive a max of 25 hours of use a year at off throttle conditions. Many shoot for durability of 150 to 300 hours at WOT.

    Cooling System- Automotive applications use fans and radiators. Boat applications typically use "raw water cooling" which circulates raw water from below the boat through the engine and out the back. This cooling method is one of the reasons they are not yet using the larger automotive aluminum engines and are sticking with the cast iron truck engines. Some boats use "fresh water cooling" which circulates an ethylene glycol and water mix (similar to what is used in automobiles) through the engine and heat is transferred to raw water (lake water) in a water to water heat exchanger. "Fresh water cooling" is frequently used in salt water and commercial applications.

    Outboard Crank Orientation- Outboard engines have a vertical crankshaft while many other engines of their size have horizontal crankshafts.

    Explosion Proofing- Many of the engines accessories (like alternators) and fuel related parts (like spark arrestors for the carburetor) are specially designed to reduce the possibility of sparks igniting fumes or leaky fuel lines.

    Emissions- Automobile engines have been heavily regulated to reduce emissions due to their numbers. Until recently, boat engines had it much easier. Thus the continued use of carburetors as an alternative to electronic fuel injection which is more efficient and "cleaner", but costs more money.

    Carburetors - Manufacturers are very cost driven in the industry and use carburetors vs EFI as a result (and as a result of not being under emission regulations stiff enough to get rid of the carbs). The carburetors on many marine installations run at an angle to horizontal (inboards tilt the engine down), also during takeoff of stern drives the boat attitude (angle to horizontal) changes greatly as the nose first comes up and then later breaks over flat. Not running horizontal plays havoc with carburetor performance and design. Along with this problem comes high altitude operation - many boats are ran in mountain lakes at high altitudes - they require special carb settings and sometimes special gearing. Additionally, spark arrestors are used with marine carburetors.

    Fire Protection - In a car if a fire develops you can stop and get out. In a boat that can be a much more serious situation so many additional regulations concern switches, electrical lines, fuel lines, spark arrestors, and engine accessories. Also special fueling procedures are followed including the use fans in the engine compartment to expel fumes.

    Corrosive Environment - Cars are hot under the hood, boats may be hotter but they are also exposed to a corrosive water and sometimes salt water environment that eats away anything not properly protected.

    Torque Curves - The profile of the engine torque curve (Torque vs RPM) is different for the two applications.

    Horsepower Trends- Automotive engines have been coming down in horsepower and going up in efficiency to get improved mileage. Boating engines have still been going up in horsepower.

    Steering System Demands- Automotive steering systems have their largest horsepower requirements when the vehicle is parked or moving slowly. They are very easy to steer at high speed. Recreational power boats are just reversed. The steering systems require very little power at slow speeds and their peak horsepower requirements are at maximum speeds. Boats are typically steered by using the drive as a rudder and turning it to one side at high speed takes a great deal of power.

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