Proposal for Research Paper

     In the automotive industry, the attainment of greater fuel efficiency and power is paramount to creating more competitive vehicles for consumers to purchase. One of the methods that automakers have employed is Direct-Fuel Injection (GDI) technology, a type of fuel injection that has been common to diesel engines for decades, but is only now becoming popular in internal gasoline combustion engines. Direct-fuel injection sprays fuel directly into the cylinder for a more controlled combustion process, as well as for a leaner air/fuel mixture when compared to traditional port-fuel injection. This more precise fuel-delivery method amounts to better fuel-efficiency under all conditions, including light load and full load on the engine. In short, direct-fuel injection maximizes an engine’s efficiency by reducing the amount of wasted fuel in the combustion process.

     Despite the benefits of this fuel injection technology, major issues have begun to surface in recent years with regards to the cylinder valves in GDI engines. With GDI engines, fuel does not wash over the valves during the combustion process like it does in port-fuel injection motors. Since fuel does not contact the valves, the harsh and sooty exhaust gases that exit a cylinder in a 4-cycle combustion engine gradually build up a layer of carbon on the necks of valves. In a port-fuel injection motor, these carbon deposits are continually removed by the flow of gasoline over the valves in normal driving. However, this build up of carbon on the necks of valves in a GDI engine cannot be removed in normal driving. In addition, very few automakers have maintenance schedules that call for valve cleaning, which furthers the problem, because a driver would be unaware of the growing issue within the engine of his/her vehicle. Lastly, these carbon deposits could eventually lead to engine misfires and trouble starting the vehicle, as well as reduced fuel efficiency and a noticeably rougher idle. This issue is becoming more and more of a concern given that many automakers are touting the benefits of direct-fuel injection, especially when it’s combined with turbocharging.

     This inherent problem with Direct Fuel injection is made worse by the fact that automakers have not issued recalls or service bulletins to consumers that their vehicles need regular servicing to diminish excessive carbon buildup on the engine’s intake valves. This lack of communication could eventually cause companies like Ford, with their many “EcoBoost” direct-injection turbocharged engines, to be the source of many complaints and owner lawsuits, as was the case with Toyota when cases of sudden, unintended acceleration occurred on a number of vehicles up through 2011.

     In order to alleviate this growing problem with carbon deposits on the necks of the valves in GDI engines, I propose that automakers install additional valves within the engine that transport fuel from the direct injector into the cylinder. This will effectively eliminate carbon build up by allowing fuel to wash over the valves that transport fuel from the direct injector into the cylinder. This method injecting fuel into the combustion chamber will be less efficient that one hundred percent direct-fuel injection technology, but it will be more efficient that port-fuel injection. Furthermore, this proposal will eliminate any expensive valve cleaning that direct-fuel injection engines need on a regular basis.

     In addition to implementing both port and direct-fuel injection within an engine, automakers should not only promote the benefits of direct-fuel injection, but also communicate to consumers what the long-term maintenance program looks like for GDI engines. This could cost an automaker customers in the short-term, but in the long run, the automaker will save money by having less lawsuits and less damage to image of the brand. Automakers can start notifying consumers of the maintenance required with GDI engines by issuing a service bulletin for existing customers, as well as including an intake valve cleaning as part of the maintenance schedule in the owner’s manual that comes with every new vehicle sold in the United States.

     This proposal has already begun to take affect within the automotive industry, with Toyota, Lexus, Volkswagen, and Audi implementing this fuel injection design into their vehicle engines. This implementation will become more of a possibility as automakers redesign their vehicle engines to meet the EPA fuel economy standards in 2016, thus reducing expensive design changes to existing engines that already have the problematic direct-fuel injection technology.

     Many other methods of dealing with carbon deposits on the valves in GDI engines have been proposed and implemented, but they have not been permanent solutions. These proposals include extended amounts of time revving an engine over 3,000 rpm to burn off carbon deposits, walnut shell blasting the engine valves, and adjusting the timing of the intake and exhaust valves to reduce exposure to dirty exhaust gases within the combustion chamber.

     In the case of revving an engine over 3,000 rpm to burn of carbon deposits, the amount of time needed to do this is at least 20 minutes, an impractical amount of time for the average driver. In addition, this process needs to be completed on a regular basis, which adds up to larger fuel bills and the possibility of excessive wear on the seals and pistons of the engine as it revs at a higher rpm. Walnut shell blasting the engine valves is a more effective method of ridding the engine of carbon deposits, but it is expensive, and it must be performed every 20,000 to 30,000 miles, which is about once every two years for the average driver. Lastly, a few automakers have adjusted the timing of the intake and exhaust valves so that they are exposed to dirty exhaust gases for a shorter amount of time compared to other GDI engines. However, this only slows down the formation of carbon deposits on the engine valves, and so vehicle owners will still need to bring their vehicle to a repair shop to have the valves cleaned, albeit not as often as other vehicles with GDI technology.

     My proposal for adding extra valves within the engine and communicating the downsides of GDI technology to car buyers will not only get rid of carbon deposits, but it will also maintain the efficiency of direct-fuel injection and the reliability of port-fuel injection engines. This proposal is also the best method of resolving this growing issue involving carbon deposits on the engine valves, and as automakers strive to improve the fuel efficiency and power of their vehicle engines by adding direct-fuel injection, the need to implement my proposal continues to grow.