Gasoline Direct Injection (GDI)

Final compression pressures are different so that you have to take it into consideration.

If you want to modify a diesel engine then you should decrease the compression final pressure.

There has been a lot of engineering in GDI technology and that will continue for many years to come. Start your quest for knowledge here. http://www.tscombustion.com/tscitechnology.html

Hi,

A very advanced version of GDI has been in use for several years at BRP - see www.BRP.com - who manufacture high performance engines under the Evinrude and Rotax brands. We use Evinrude outboards and they have VERY low fuel consumptions and very good power to weight ratios compared to four stroke EFi engines. BRP have a very good video / DVD showing how their very fast high pressure electric injectors work.

Good luck

HM

If you want to build a demonstration model only, and dont care about appearance, try this:

Break all of the porcelain from the same type spark plugs you are going to use.

Break off the ground electrode and braze a nipple to the remaining base (top).Add the injector at the end of the nipple, and new spark plug at the side, via a tee fitting, or by drilling and tapping the nipple.Keep the nipple as short as possible.Once the engine is up to temperature ,it will be more efficient because the fuel will vaporize better, and the plug will send a large flame down the nipple to ignite the mixture.

This is not a perfect configuration, but it will illustrate the basic principle.You still must have a method of determining TDC of the engine and calculating when to fire the injector and plug, and sufficient fuel pressure.

Hope this helps

EZStreet

As stated this technology is already used in production 2 stroke motors. It is found in Ski-doo snowmobiles and BPR, Johnson, and Evenrude out board motors.

Bombardier or BPR is a part of/ owns all these companies. They have advanced this technology tremendously. Now main stream.

Hondo

Even my moms 2004 Isuzu Rodeo has direct injection

You can use an already existing engine, but the modifications are not easily accomplished. First you must install an injector directly into the combustion camber and that means drilling the head in a location where you miss the valves, the water jackets (if liquid cooled) and the spark plug! You may have a hard time finding that sweet spot! Then comes the trouble of finding/using an injector that will not be destroyed by the heat, pressure and concussion of being inside the combustion chamber. You will also have to develop a fuel delivery system that is extremely high pressure so that it can force the fuel into a running engine at top dead center on the compression stroke. The amount of pressure required will be a minimum of several hundred psi above the cylinder pressure that the engine develops. It is do-able, but not with things that are sitting in your kitchen junk drawer, or at the local hardware store.