« Ozone Triggers Overreaction in Innate Immune System Response in Lungs | Main | Gaz de France, Vattenfall in CO2 Project in Germany »
Polaris Introduces ATV With New Air-Assisted Direct Injection Engine
30 September 2007
 |
| The Orbital two-phase, air-assisted injector. Click to enlarge. Source: Orbital |
Polaris Industries Inc. has completed first production of its newest military vehicle, the MV800 4X4 ATV, and received purchase orders for it from the US Department of Defense. The MV800 is Polaris’ first vehicle to feature a 760cc, 30kW (40 hp) twin-cylinder 4-stroke engine that utilizes a newly developed air-assisted direct-injection combustion system.
The new Patriot Engine uses JP8 as the primary fuel. Developed in partnership with Australian-based Orbital Corporation, it delivers almost twice the horsepower of traditional diesel compression engines of comprable size.
Overall vehicle performance is thus the same or similar to Polaris’ gasoline-powered family of Ultra-light Tactical Vehicles for the military. In addition to running on JP8, the Patriot Engine can operate on emergency fuels including gasoline, JP5 and highway diesel.
The new production launch represents the culmination of a two-year program between Polaris and Orbital to develop a spark ignited engine running on kerosene without sacrificing the performance of the gasoline engine.
This product launch is a key milestone in the development of new markets for Orbital direct injection technology. This is the first 4-stroke production application and we see this as a key step in expanding the capability to many other engines and markets. The initial market for this product will be the military, but the flexibility of the Direct Injection system has now been proven, and we see the potential for other commercial multi-fuel vehicles and gasoline engines going forward.
—Rod Houston, Orbital CEO
Rather than using high-pressure injection to atomize the fuel charge, Orbital uses an air-assisted, low-pressure direct fuel injection, combustion and engine management system: the Orbital Combustion Process (OCP) technology.
With OCP, fuel is first metered into an injector pre-chamber via a conventional automotive port injector (MPI), and then delivered into the combustion chamber with the assistance of air at pressure. The air-assisted injector decouples the fuel metering and delivery events, thereby assisting the dynamic range of the injector, according to Orbital.
Resources:
Experimental and Theoretical Study of an Air-Assisted Fuel Injector for a DISI Engine (SAE 2007-01-1415)
September 30, 2007 in Engines, Fuel Efficiency, Vehicle Systems | Permalink | Comments (10) | TrackBack (0)
TrackBack
TrackBack URL for this entry:
http://www.typepad.com/t/trackback/22062/22034056
Listed below are links to weblogs that reference Polaris Introduces ATV With New Air-Assisted Direct Injection Engine:
Comments
I'm not sure what's so great about this engine, other than Oribtal finally getting to flog the air-assisted injection system it originally developed for lean-burn operation of two-stroke designs.
The smart fortwo CDi has a 3-cylinder 799cc common rail diesel engine delivering 33kW (41hp) and meets Euro4 when equipped with a particulate filter. This Polaris design has two, larger cylinders producing about the same amount of power. I suspect the US military could have saved itself a lot of money by just buying the smart's motor off the rack. The conversion to JP8 is not all that hard.
Posted by: Rafael Seidl | Sep 30, 2007 10:16:45 AM
Rafael,
You missed the point. Being Spark Ignited you can get rid of the weight disadvantage of diesels. Assume they also passed rigorous could start test to get Mil approval. Both points are nothing to sneeze at, and that is not also mentioning the ability to burn other fuels in an emergency.
Posted by: enginegeek | Sep 30, 2007 10:29:33 AM
Yes, the key feature is the ability to run on gasoline also. However the engine probably does meet emission standards on both fuels, so in that respect it is not really GCC compatible. There is the possibility that this may be a lower cost GDI system however.
Posted by: John Schreiber | Sep 30, 2007 11:13:06 AM
The news bit has nothing to do with GHC but since its here,lets understand what the product is.
First of all the military is buying a ATV not a mercedes diesel engine.
Second is weight,third is cost of a diesel over a spark ignited engine(both with DI).
Lastly as pointed out it can run on any fuel including gasoline show me a diesel that can do the same.
Posted by: Ralph | Sep 30, 2007 11:31:15 AM
@ enginegeek -
for engines that small, there isn't a whole lot of weight difference between spark and compression ignition any more. You're basically limited by the minimum wall thickness possible in casting technology.
Cold starting is definitely an issue for regular highway diesel, that's why the primary fuel here is JP8. There are also military grade diesel fuels that remain liquid down to very low temperatures.
So that leaves multi-fuel capability, though the alternatives are all listed as emergency fuels. Granted, it is probably very useful in something that will be used mostly as a scout vehicle. However, diesels can run on SVO or even filtered WVO for quite a while in a pinch (at least if they don't need to meet stringent emissions regs), whereas gasoline is often hard to come by in a war zone. Indeed, the very reason JP8 was chosen as the primary fuel is that the US military is trying to standardize on a single fuel grade to minimize its logistics effort.
As for cost - members of Congress aren't exactly known for pinching pennies on military hardware, because that's one way they bring home the bacon. I would be very surprised indeed if this Polaris engine were any cheaper than something smart (indeed part of Mercedes) has already produced close to a million units of.
Posted by: Rafael Seidl | Sep 30, 2007 1:03:22 PM
This could applied to Evinrude and Johnson outboard motors since they also use Orbital fuel injection technology.
Posted by: gary | Sep 30, 2007 1:10:35 PM
Rafael,
Points taken. However, if it was such an easy choice, why did they not go diesel? My guess, is a combo of weight and power. Others have come to Polaris's conclusion as well using Orbital's technology. Sea and Air came before Polaris's Land application. Look at these other applications:
http://www.mercurygovsales.com/technology/optimaxjp.php
http://www.barrus.co.uk/special_products.php
http://www.hirth-uavengines.de/
Posted by: enginegeek | Sep 30, 2007 1:13:59 PM
Gary,
Not the Injectors completely different. There is a long story about a lawsuit between the old Johnson/Evinrude and OE, but that is for another day....
Posted by: enginegeek | Sep 30, 2007 1:17:39 PM
@ enginegeek
From what I remember the old OMC "Ficht system" used a Siemens electronic injector, not an Orbital product. They used stratified mix at lighter loads, and spark plugs had a very short life.
Please expound on this especially if I am wrong.
Posted by: John Schreiber | Sep 30, 2007 7:06:24 PM
The US DOD (Dept.of Defense) has been emphasizing diesel-fuel-capable small engines running near stoichiometric ratio for maximum power density while still having low smoke output suitable for military combat mission.
Not surprisingly, this Orbital injector will fit the bill because it allows a low-cost low-tech low-pressure injector to provide for direct fuel injection during the compression stroke to provide homogenous mixture for spark ignition to approximate the Otto cycle for maximum thermal efficiency and power-to-weight ratio at lower compression ratio than the Diesel cycle.
Maximum fuel efficiency using denser diesel fuel at higher compression ratio is less of a priority to the US military than the ability to use JP8 (jet fuel) optimally in those small, light and simple engines.
Posted by: Roger Pham | Sep 30, 2007 9:14:52 PM
