DESIGN
Here lies the heart of Gryphon Diesel Engines proposal. With several innovative tested technologies, we will offer a 2-stroke diesel engine with long engine life, fewer cylinders, low-cost engine production and overhaul, up to 80% fuel savings, 50% weight reduction and “near-zero” to “zero” emission with unequaled performance compared to other diesel engines on the market. Cylinder head and block casted in one piece to reduce weight, parts, production costs and provide exceptional strength. The technology, alloys and all sub-systems described within this section are already in production and made available to GRYPHON DIESEL ENGINES, LLC by Silva Technologies, Inc. This makes ours a market-pull approach that will stay within controlled costs and a proposed time-frame, all of which greatly reduces the risk of investing in our engine line development. Our product is guaranteed to deliver superior customer value for years to come with its ability to address the needs of the Marine, Piston Aviation, MHDC trucks, Power Generator and Non-Automotive markets.
The engine crankcase of our 2-Stroke engines may be sealed just like those in 4-Stroke engines, to isolate the oil from the air/fuel mix, avoiding the traditional contamination of the oil as well as poor exhaust emissions. Air comes into the combustion chamber from below the piston and below the compression rings but above the oil ring, effectively sealing the oil pan and allowing the piston to work at far lower thermal loading.
Our engine line will offer a variety of engines that can be used for all four applications. Advantageously, the four engine block configurations we have generated have over 90% common parts.
Features of the Core Design
Scalable Engine Architecture (SEA) and Compact Engine Architecture (CEA)
All of our engine configurations will use over 90% common parts under the SEA concept of one-part-fits-all. There are several benefits to employing this concept. SEA lowers stocking costs and substantially reduces the costs of manufacturing, assembly and replacing spare parts. Common parts will be more affordable. It allows the possibility of exceeding 95% assembly automation of the whole engine. In addition, there can be more mechanics trained to work on Gryphon Diesel engines than on any other engine, worldwide. This unique design concept is hardly used even in the current land-use diesel engine market, which contributes to the high expense of diesel engines compared to gasoline engines.
Compact Engine Architecture allows us to pack the engine in such form which is suitable for all the four applications without any substantial modifications, as well it allows to add features and systems as per OEM request for particular applications such as aviation and power generators. The 2-stroke approach is very suitable to CEA design.
SEA and CEA offer solutions to some problems that come from the high cost of current diesel engines.
Lightweight Metals
- Magnesium Alloy: Engine Block
Magnesium (Mg) alloys have typically been avoided because of the difficulty in preventing creep and corrosion. However, the Mg alloy Gryphon Diesel engines will use has overcome both of these obstacles. This Magnesium alloy is 33% lighter than Aluminum. It is alloyed with a cathodic solution that makes Magnesium 90% to 100% corrosion-free, i.e. stainless, and it is creep resistant. In addition, it is heat resistant, its bolt retention is a bit higher than Aluminum 319, and it has much higher tensile strength at any temperature [substantially higher at temperatures above 150 °C (300 °F)]. This alloy has been road tested during two years in Europe for over 65,000 miles on a 4-cylinder high compression 18:1 diesel engine. After inspection, it passed with flying colors.
To cast this engine block, we will use a new casting machine that has been specially designed to make all-Magnesium alloy engine blocks.
This alloy will provide very lightweight shock absorbency and damping capacity, which will make airplane cabins quieter and will also provide better overall Electromagnetic Interference (EMI) shielding.
Gryphon Diesel engine blocks made with this Mg alloy will be 30%-33% lighter than if they were made with Aluminum. Gryphon Diesel has also available two extruded Magnesium alloy with tensile strength around 525 Mpa (it can be made higher). This is much higher than common Aluminum alloys, and it may be used to substantially reduce the weight of many machined parts.
- Lightweight Steel, Titanium, Metal Matrices: Internal Components
All internal components that require Steel, like crankshafts, pins, and dowels will be made from a special lightweight Steel (6.8 g/cm3), which is not only 17% lighter than normal Steel (7.8 g/cm3) it also has better ductility, a slightly higher tensile strength, and a capacity to be heat-treated to RC 70 without becoming brittle. This is a first-time achievement for lightweight Steel.
Some engine parts may require Titanium (Ti). Recently the cost of manufacturing of Titanium has been reduced by 90%, with a supplier in the USA already taking small orders of shafts, pins, conrods and other similar parts. Additionally, the heat-treatment of Ti can now be done upwards of Rc 70, and to its core, without becoming brittle. These are first-time achievements worldwide.
Also available is an affordable Aluminum alloy whose 1.2 GPa tensile strength is superior to Titanium’s 0.95 GPA. We may use it to make conrods because this metal composite offers substantial weight reduction, it lowers friction and improves internal engine balance for superior performance and smoothness.
Diesel engine pistons now can be made from a newly developed high-strength Aluminum, originally designed for high compression diesel engines. This further reduces engine weight, compared to the more commonly used Steel, and allows for better-balanced diesel engines by enabling reciprocating forces.
GRYPHON DIESEL ENGINES, LLC has the proprietary know-how to manufacture all of the Magnesium alloys, lightweight Steel, low-cost Titanium and Aluminum Alloys parts, by outsourcing the manufacturing.
Metal Treatment
All moving and coated parts will be submitted to an automated cryogenic processing treatment (Cryo treat, LN2) in order to reduce substantially the wear and tear of internal moving parts. This treatment process tightens crystals into a very compact chemical structure, which generates a metal that is very hard and that has very low porosity. The moving parts made of this cryogenically treated metal thereafter have a very long lifespan and a greatly increased resistance to metal fatigue and wear. This will give our engine parts an exceptionally long operational life, excellent reliability and resistance to wear. This treatment will be done in-house, and will be controlled by proprietary software programs.
Casting and Packing
The diesel engine block will be cast in one piece in a monoblock design so that the cylinder block and cylinder head are not separate. This design will be applied to Single piston, Inline 2 and 3 cylinders and V6 configurations.
Gryphon Diesel engines will be packed to fit both marine and aviation applications, which require the tightest overall dimensions of all four markets. As such, for each engine configuration, the cowling, or engine cover, of outboard marine engines and aircraft piston engines will have a similar shape and dimensions. For aviation applications, due to small engine footprint dimensions, the cowling can be much more aerodynamic than traditional reciprocating cowlings. These aerodynamic benefits yield an additional 8 HP.
Weight Reduction
A substantial percentage of weight concentration in a diesel engine is in the engine block and cylinder head. The monoblock manufacturing process, Magnesium materials and other lightweight materials will all reduce exponentially the combined weight of the engine block and internal parts compared to current diesel engines or even 4-Stroke gasoline engines. We aim to build an engine with a power-to-weight ratio up to 0.40 lb/hp. This refers to the main engine alone for marine applications and the ready-to-mount engine for aviation applications, excluding any gear-housing. Gear housings will also use the same Magnesium alloy to further reduce weight.
For the internal components, the average weight reduction is close to 33% if we combine the results of the low compression design with the new lightweight Steel. As for reciprocating parts, the weight of the pistons and conrods are reduced by 25%. As a result, mechanical friction and parasitic losses of energy are greatly reduced to below that of an average gasoline engine. There is also the added advantage of much better engine balancing with reduced weight.
Additionally, Gryphon Diesel Engines are very low-weight because they use 1 to 2 fewer cylinders. Virtually all manufacturers of gasoline outboard and piston aircraft engines use 3 and 4 cylinders for engines of 25 HP to 200 HP and 6 to 8 cylinders for engines of 225 HP and above. We propose to use only 2, 3 and 6 cylinders, with two engine blocks and 90% common parts for engines with 75 HP and above. Gryphon Diesel proposes to use 2 cylinders for engines of up to 100 HP and 3 cylinders for engines from 75 HP up to 350 HP. The V6 block will deliver from 350 HP to 800 HP. This will provide excellent production and retail cost savings and exceptional weight reduction.
NOTE: In the aviation field, 5% weight savings is a substantial achievement. We can reduce engine weight by about 33% compared to engines made 100% from Aluminum with similar horsepower output. We can achieve even further weight savings by reducing the amount of fuel an aircraft has to carry for the same travel distance. This is an enormous performance and cost advantage!
Coating
The engine block may be externally coated with pure Aluminum to enhance long-term protection.
All internal coatings will be of the diamond-like coating (DLC) type in order to achieve exceptionally low friction and hardness. Internal holes, or bores, will be coated with a newly-developed automated DLC coating machine, a machine that makes it possible to coat bores up to 40 ft. (12 m.) in length. This machine has proven to have an effective multi-bore coating process for coating engine blocks and cylinder liner bores with 5 to 8 microns of DLC coating deposition thickness per minute. It is all completed without any need for post-machining.
Low-Compression and Green Technology
Gryphon Diesel engines will operate at a low compression ratio of about 13:1 to 14:1, which is a new approach to diesel engine design. This is much lower than the average compression ratio of current diesel engines, which is 18:1 or higher. Higher compression ratios require thicker, and therefore heavier and oversize, internal engine components and engine blocks. Because of the lower compression ratio, our engine parts do not have to be as thick and heavy as other engines. Therefore, the engines can achieve significant weight reduction through structural block optimization. Also through this optimization, we can make the engine blocks thickness similar to that of a normal Aluminum-made gasoline engine with the same horsepower output, which further reduces exponentially the engine weight.
Low compression also provides superior optimization of combustion timing. In low compression engines, compression temperature and pressure decrease at the top dead center (TDC). While this lower temperature makes the ignition take longer when fuel is injected near TDC, it enables a better mixture of air and fuel. This results in a highly efficient diesel engine in which a higher combustion expansion ratio is obtained. The higher expansion ratio prolongs the delivery of torque to the drivetrain. Current high-compression diesel engines can only deliver a short, super strong and very destructive force to the drivetrain. Low compression makes it possible to deliver high torque throughout the expansion of the piston, which yields greater efficiency. With low compression, our engine exhibits a flat torque line, which means that it has high torque from the low end to the high end of the RPM (Rotation per Minute) engine range.
Low compression also substantially reduces the formation of NOx and soot, the main causes of diesel pollution and black smoke. In low compression engines, there are no localized high-temperature areas and the optimal mixture of fuel and air decreases oxygen insufficiencies. This makes combustion much more uniform throughout the engine, which minimizes harmful combustion waste. Thus, our engine complies with global emissions regulations, and does not even need expensive NOx after treatments systems. This makes Gryphon Diesel the producer of a truly green “near-zero” emissions diesel engine. Mazda’s Skyactiv-D engine, in use in Europe and Japan, has already demonstrated this. Our initial emissions goal is for the engines to produce no more than 0.001 g/km of fsDPM (particulate) and 0.001 g/km of fsNOx. So far, 0.01 g/km fsNOx has been proven in testing by Sandia National Labs using high compression engines that were only equiped with a Supercritical Fuel Injection (SCFI) system (see Special Systems).
Finally, in low compression engines, cold-start ignition of the diesel fuel, even at temperatures below 0 °F degrees (-18 °C), can easily be accomplished using high temperature ceramic igniters (ceramic glow plugs) and multi-hole piezo injectors [optional Multi-point Laser Ignition (MLI) system is available (see Special Systems)]. These injectors allow for a variety of injection patterns such as pre-injection, main injection and post-injection, which ensures cold-start capability. Each injector will carry its own chip, which will allow each cylinder to be tuned individually. This contributes to a more-balanced engine and results in an additional 2% fuel reduction (NOT included in the fuel reduction estimates). Denso Systems developed this and Toyota uses it in Brazil.
Injection System
As with all diesel engines, Gryphon Diesel engines will have direct injection.
We will use an electronic fuel injection pump up to 1,700 bar controlled by the electronic control unit (ECU). There will be electronic control of the ceramic igniters or optional MLI, the electricity-driven supercharger(s) for superior performance and exceptional all-wide torque band (from low to high) and all electric-driven pumps.
Liquid-cooling
Our engine will be fresh-water-cooled, which reduces engine fatigue in aviation applications. For marine use, closed-loop cooling eliminates the problem of salt-water since no salt water gets inside the engine, which is another unique feature of the Gryphon Diesel engines. For aviation use, liquid-cooling translates into lower thermal variance, which prevents engine blocks from cracking especially after landing in very cold environments.
Reducing Energy Loss
Additionally, the weight reduction we can accomplish will also substantially reduce parasitic power losses. Thermal efficiency (TE) target is 50% or higher . We employ several features that will help keep parasitic energy loss at a minimum: electricity-driven water and oil pumps and superchargers, exhaust-driven generators (6-7 KW), the use of only one piston compression ring and one oil ring that will require very little oil and therefore reduce the drag that internal oil sloshing brings. Cylinder sleeves will be DLC coated to substantially reduce piston friction. Piston top will be coated with Silicon-reinforced Porous Aluminum (SiRPA) to reduce heat loss and increase thermal efficiency.
All of these factors will increase the overall net shaft horsepower output.
Supercharged or Crankcase Aspirated
Our engines with power ratings of 75 HP and higher will be equipped with either single or twin superchargers; engines with power ratings of 55 HP and below will be naturally aspirated (NA) through the crankcase.
The superchargers will be electricity-driven and controlled by the electronic control unit (ECU) for the highest performance throttle response, especially when accelerating from being idle (i.e. the “out of the hole” throttle response), which will eliminate the problem of lagging.
For the aviation application, by means of continuously adjusting to altitude pressure, the supercharger provides unequal performance that will outperform comparable turbines in the range of 450 to 750 HP in takeoff, climbing and at-altitude engine performance. The superchargers will deliver continuously sea level maximum power at altitudes up to and including 28,000 feet, unlike turbines which degrade in performance at higher altitudes. The service ceiling for Gryphon Diesel engines is 33,000 feet.
The electric power will be provided by an exhaust-driven generator (6-7 KW) and when needed, supplemented by the latest Magnesium battery.
The target output rating for single supercharged engines is a minimum of 100 hp/liter, which is the same as turbo-charged automobile engines in Europe. For the twin-supercharged version, the target rating output is a minimum of 200 hp/liter. This is the same output as that of the Mazda diesel 2.2 liter 4-cylinder low-compression engine used for the 24-hour Le Mans race in the LMP2 class which delivers 450 HP total or 205 hp/liter and 600 lb-ft of torque with its twin-turbocharger and 58 psi boost.
Crankcase aspirated engines target to produce upwards of 55 hp/liter without exerting as much effort as current diesel engines do. The horsepower ratings of Gryphon Diesel engines will be tuned (or de-tuned) to match the current market segment ratings of the engines used in the four markets to target. This is attained by electronically controlling the fuel-air mix management with MAPP and with the electrically-driven supercharger(s) application. MAPP is the software that runs the whole engine. To achieve several horsepower ratings out of the same engine block, we will design the engine for the maximum rating and then de-tune it by adjusting the MAPP software to suit that horsepower rating and application.
Fuel
Our engine will burn regular diesel, Jet-A, and 100% bio-Diesel fuels. It may burn other Kerosene-based fuels, but no Naphtha-based fuels will be recommended initially. An optional Emulsion Fuel Device (EFD) will be offered to allow mixing of up to 15% water to diesel. This 15% diesel fuel reduction is not included in the above fuel reduction estimates. (See Special Systems)
Fuel Efficiency
Fuel efficiency will vary across marine, aircraft, MHDC truck and power generator applications.
In marine applications, diesel engines yield a documented fuel reduction of 30-33%, on average, in comparison to gasoline engines delivering the same performance level. Gryphon Diesel engines will be able to achieve an additional fuel reduction of 30-32%, or a minimum total of 62-65%, by using a forward-facing rather than a rear-facing propeller configuration (Azimuth-type drive).* Note that this measurement refers to MPG in miles traveled, not the brake specific fuel consumption (BSFC). We can achieve up to 20% additional fuel reduction with our low-compression design. Finally, we are sure to achieve an additional 10%-15% fuel reduction rate by integrating the SCFI system. This tested and proven technology, with proper engine optimization, will likely yield even better results of up to 30% fuel reduction. If we choose to use the MLI system, we may gain an additional fuel reduction rate in gallons per hour of up to 5%. By integrating all of the fuel reduction methods described here, which no other manufacturer has done yet, Gryphon Diesel engines may achieve fuel reduction, per mile traveled, in excess of 80% compared to current gasoline marine engines with the same performance, specially outboard engines.
In aviation piston engine applications, we anticipate a baseline fuel reduction rate of up to 40% compared to current 4-Stroke AvGas gasoline engines with same power rating or 60% when compared to turbines. In addition, the lower compression ratio of our engine will achieve up to 20% further fuel reduction. Finally, the implementation of an SCFI system will achieve an additional 10-15% reduction (or possibly up to 30% fuel reduction at full optimization), and with MLI another 5%. In total, our design will provide over 70% reduction of fuel consumption for aviation piston engine applications using diesel fuel, and a minimum of 60% using Jet-A fuel. This translates into >80% reduction of fuel consumption when compared to turbines with same horsepower ratings. SCFI also reduces the weight of the total fuel carried for the same trip by a very high percentage, which further reduces overall weight substantially, improves overall performance and provides a huge reduction in operational costs.
For the MHDC truck hybrid diesel engine applications, in combination with the Magnesium batteries, it may reduce the total fuel consumption by >80% with low compression, SCFI, MLI and electric grid charging. With Magnesium batteries charged by the regular electrical grid, the diesel engine may not need to operate, thus it may reach 100% fuel reduction and emissions pending on speed and miles traveled per day/trip and the kWh capacity chosen. Li-ion battery pack is an option.
In the power generator application, the low compression of Gryphon Diesel engines promises a minimum of 60% lower fuel consumption than gasoline generators and 30% lower fuel consumption than other diesel generators currently on the market. Adding SCFI technology may further reduce fuel consumption by up to 10%-15%, and with MLI by another 5%, which brings the total fuel reduction to about 45%-50% when compared to current diesel powered generators, or >75% to gasoline powered generators.
Operational Life
Gryphon Diesel Engines anticipates achieving 10,000 hours of operational life, at the minimum, for high RPM operating engines before the need for overhaul and 15,000 hours for the low RPM engines. This is an excellent improvement on the 1,500 useful hours, on average, for current 4-Stroke gasoline engines in the marine, piston aviation applications and generator applications, and 5,000 hours for turbines.
Gryphon Diesel engines RPM will reach a minimum of 5,500 RPMs for the I-3 block, and 3,000 RPMs for the V6 block. Such low RPMs decreases the amount of wear and tear on the engine. Diesel engines also develop much more torque at much lower RPM rates with a flat torque curve than current gasoline engines. This is excellent for better generation of electrical power in the marine environment, for aircraft applications or for drones. Higher-amps electronic onboard generators can be available, especially to supply power for Synthetic Aperture Radars in UAVs and energy-based systems that are ever smaller but have increasing energy demands.
Also, we will use wet, replaceable, DLC-coated cylinder liners in order to extend the useful life of the engine block.
Furthermore, it is normal for diesel engines to have three or more extended service lives after total basic overhaul (TBO), but the same cannot be said for most gasoline engines, especially outboard engines. Additionally, turbine engines are limited by cycles. A cycle is counted once every take off and requires a costly turbine overhaul after a certain number of cycles or hours, whichever occurs first. A typical turbine requires cycle service between 2,000 and 6,000 cycles or about 5,000 hours. In aviation, for short flights, this becomes cost prohibitive, one reason helicopters are expensive to operate. Gryphon Diesel piston engines are not cycle-limited and only require basic normal maintenance. Short flights, such as island hopping or helicopter operations, can accumulate many more cycles than hours, making Gryphon Diesel piston engines the most cost-effective alternative without the high annual overhead imposed on operators.
Reduced Cost
Gryphon Diesel Engines can lower the overall retail cost per diesel engine because of its much smaller engine block that uses fewer cylinders, its reduced production cost and its fewer engine parts to manufacture and assemble. Lower retail cost is essential to achieve high volume of sales, which also drives down the cost and helps to seize the highest percentage of the market share.
Our engine design also substantially reduces the overhead costs of spare parts to dealers and distributors. Also, with this design approach, the whole engine assembly may exceed 95% automation, which further reduces production costs.
Magnesium Batteries
Batteries will not be included, but a new rechargeable Magnesium battery will be offered for separate purchase as soon as it becomes available. They will be supplied to OEMs right from the start of engine testing and evaluation. ‘
Stemming from research and development of fuel cells late 2015, a new electrolyte has been developed [Mg (CB11H12)2/tetraglyme (MMC/G4)] as well as a special high capacity/high voltage cathode for a regular rechargeable Mg battery.
A second rechargeable Magnesium battery has been unveiled, October 2016 in Japan. Production is expected to begin in 2018.
Magnesium ions in the batteries’ electrolytes transmit electricity by carrying a double positive charge, and this increases the device’s energy density, i.e. the amount of electricity the battery can store. Compared to Li-ion batteries of the same capacity, the Magnesium battery has nine times the energy density (possibly 12x), five times the discharge rate, it takes 80% less time to recharge, and it is about 30% less expensive. To illustrate Magnesium’s superiority over lithium, an electric bicycle with a fully depleted lithium-ion battery needs about three hours to recharge fully. If equipped with a Magnesium battery, the process would take a mere 36 minutes.
Additionally, Magnesium batteries are not prone to ignite under high temperatures or overheat like Lithium does. This was made painfully clear when the lithium-ion batteries in a well known commercial aircraft, the Dreamliner, caught fire, leading to a brief grounding of the planes until the fire hazard was resolved.
Also, lithium batteries ordinarily cannot operate properly in temperatures below 5 °F. Magnesium batteries work fine at temperatures as low as -22 °F and as high as 131 °F.
Lithium is not a common metal, which makes it so expensive that the price of an electric car battery often has to be subsidised. Magnesium is more abundant and cheaper than lithium and it is easier to handle. Magnesium can already be extracted from ocean water at lower cost than mined, a zero human disruption (mining is man’s most disruptive activity in the world). Our prototype batteries will be manufacture from this ocean extracted Magnesium.
These factors give the Magnesium battery superior electrical performance, and at a 30% reduction in cost, near or below $100 KWh. As a point of comparison, Tesla Motors hopes to reach $200 KWh by 2020 and $165 KWh by 2025 only, with its very expensive Li-NCA batteries.
The Magnesium battery is an excellent green choice as it provides 100% electric operation (i.e. zero fuel) in marine applications, especially outboard engines, with exceptional long-range capability for trolling, if matted with solar panels, as well as for nearby marina operations. Our hybrid engines meet the European Union’s emissions standards when in port, which no marine engine currently achieves especially outboards.
For the MHDC trucks applications it provides an incredible long range operation and exceptional low operating costs, with a super quick 100% recharging ratio.
Additional General Features:
- Offset crank shafts for lower vibration and smoother engine operation.
- There will be an oil heater for low-temperature operation.
- We will use high-output high-density alternators, which are water-cooled and exhaust-driven (6-7 KW or higher).
- There will be a flywheel-mounted electric starter (for marine applications see Special Features).
- We will use a 48-V electrical architecture, which is the standard chosen by all electric vehicles by European automakers.
- An optional voltage regulator is available for existing 12 V or 24 V systems, to make engine repower easier.
- Engines will work in any operating position – upright, sideways or upside down.
- Engine blocks will have built-in mounting holes in order to facilitate the addition of the required hardware for any of the four proposed major applications during assembly and OEM applications.
- Manufacturing may be outsourced to third parties for casting and CNC machine work. Some parts may be manufactured in-house, especially internal parts and engine blocks.
- Engines will be sold ready-to-mount with all of the required standard features.
- Gryphon Diesel brand power generators will be sold complete, ready to use.