The Kneeslider just posted this article about a new type of 2-stroke engine that is under development. The Kossack engine uses the same rotating assembly as a standard engine, but the piston and combustion chamber have a rectangular cross section. There’s also no wrist pin between the piston and connecting rod. This means the piston and connecting rod can be made lighter and simpler. The Kossack engine can improve 2-stroke efficiency by up to 30 percent by providing better control over intake and exhaust overlap. Head over to the full article on The Kneeslider site for a lot more details and videos of an engine model and the prototype running.
When you buy a new Corvette Z06 or ZR-1 or crate engines of the LS7 or LS9, you have the option of paying $5800 to build your own engine at the GM Performance Build Center in Wixom, Michigan. You go to the plant and use the GM parts, tools and processes under the guidance of a GM technician. Stacey David recently did this to build the LS7 going into the latest project car that’s building for his show Gearz on SPEED. Lucky for us, they brought cameras along.
Russel Sutton is a man from Australia who decided to build his own 9 cylinder radial engine to put on his airboat. It uses a custom machined block and rod system with Holden Commodore V6 pistons and cylinders from Honda XR600 motorcycles. Check out Part 1 on his project for all of the build details. Sutton got the engine to the point where it was ready to start up and he captured it on video for the rest of us to enjoy. Unfortunately, having the engine run exposed some of its weaknesses that will have to be addressed before it will be blowing Russel’s hair back on his airboat. Watch the videos and read the article over on The Kneeslider for all of the details.
This article is an extension of our discussion about the complexities of combustion engines. National Geographic is following a story about a new supercomputer that the US is building. It’s called Titan and it will be ready for use later this year. Modeling a new type of combustion for engines was high on the list of things that would require the Titan’s processing power. Researchers are currently studying a new way of harnessing combustion for the use in automobiles. It’s called Homogeneous Charge Compression Ignition (HCCI) and it’s similar to diesel engines in that compression is used to ignite the air/fuel mixture instead of an electric spark. The key to HCCI improving efficiency is that it runs at much lower temperatures so that there is a lot less waste heat. However, HCCI is very sensitive to the chemical makeup of the fuel being used. That’s why the folks working on it need access to Titan in order to make a model that will allow them to study make a model of what goes on during HCCI.
HCCI requires complex fluid and chemical dynamics models
This is footage from the 2011 North American International Auto Show in Detroit. It’s the culmination of a promotion program that Ford did for the new at the time EcoBoost V6 that was going into their F-150’s. What they did was they pulled a standard EcoBoost engine off of the assembly line in their Cleveland Ohio engine plant. The engine was put on a dynamometer and put through a simulated 150,000 mile test which also included some thermal shock testing. The engine was then put into a F-150 where it was used to haul 55 tons of lumber up a mountain, tow 11,500 pounds for 24 hours straight around a track, performance hill tow testing and then its last stop was being put into a race truck that won its class in the Baja 1000. After that, the engine was taken back to Ford’s facilities in Dearborn with 164,000 total miles on it and it had only lost 1 of the 365 horsepower that it started out with. They then shipped it to the Detroit Auto Show and disassembled it for the first time in front of a live audience. The engine shows hardly any wear after the barrage of torture tests it was put through which is pretty impressive. It shows they had some talented engineers behind the engine design.
Ford is pretty ahead of the curve with this EcoBoost engine. It has a lot of the key technologies that we are going to see all car makers adopt in the near future to meet fuel mileage standards. Smaller displacement engines with turbochargers harness some of the heat energy produced by the engine to make more specific horsepower (power/liter). Direct fuel injection allows precise fuel control and better atomization in the combustion chambers. Variable valve timing changes how much the opening of the intake and exhaust valves overlap each other making sure it’s always optimized for engine speed. At higher engine speeds, the air coming into the combustion chamber is moving at a higher velocity and has more momentum. You want the intake valves to stay open longer because that momentum will keep carrying the air into the cylinder even while the piston is compressing it. The situation is different at low engine speeds when the air is moving slower. If the valves overlap too much at low speeds, the piston will actually push some of fresh air and fuel straight out of the exhaust before combustion happens. Having variable valve timing on both cams allow a computer to optimize the fuel usage and it also helps reduce turbo lag.
The video covers the entire demonstration and it runs about 50 minutes over three parts.
