This post is for William Jefferies and netters First off let me dispel a myth that fuel injection ALONE improves engine performance and economy. It does not. What is does do is improve engine operation by providing better fuel atomization which results in smoother operation of the engine throughout its operating range. In order for an engine to get better economy by adding fuel injection with NO other changes to the engine, the fuel injection would have to make it so that the required fuel to the engine for proper mixtures would be less, so less fuel is burned at the same rpm as when it was carbureted. This of course is ridiculous. Simply changing the way the fuel is introduced into the engine is not going to change the amount required for proper fuel ratio. Typically what you see happen, especially in cars is that the manufacturer, having added fuel injection and increasing their control over fuel delivery, will also raise the compression ratio, and add more timing advance, because they computer control the timing already, and have knock sensors to pick up on any detonation long before the human ear would ever hear it. This allows for the computer to then make the mixture go beyond the stotiometric or ideal mix (14.7 pounds of air to 1 pound of fuel for auto gas ) to get better fuel economy, but then as needed richen up and retard timing to protect the engine and still preserve performance, as in while accelerating. I worked in the auto industry for over 12 years as a performance technician, and found all this information very well documented in William Wynne's Corvair conversion book. The fuel injection systems that really add performance to the engine operation require being installed as a package to get that performance. The problem becomes the redundancy required for safe flight conditions in the event of the different types of failures that can occur, though they may not happen often, one has to be prepared for when that "one time" happens to you. Throttle body injection is a total waste of time, for its added complexity, fuel pressure increase over gravity systems or mechanical pumps, and its total reliance on electrical power. I have fought with alternator problems for 6 months, and I can tell you that I am very glad to have the Slick Mag and gravity feed carb, which guarantees I will keep running even with dead battery. A mechanical pump on a Corvair is a typical GM style mechanical pump capable of maintaining fuel supply even from the wings of a KR if the line is already primed and no high G maneuvers are performed. I have sat here and fantasized about how good my plane would perform with a sequential fuel injected engine installed, and if I lost that engine at some 4000 or 5000 feet that I would be fine to execute and emergency landing, no big deal. That is what we train for as commercial pilots. We CIF's are forever pulling our students engines at 3000 feet and making them find a suitable landing spot. Then the other day I had a low power situation on takeoff, where I was only climbing 150 fpm, and I felt like I did in a light twin engine plane on single engine, that I was going down, just where was I going to be forced to land. There was no where good, hangars, trees, houses, too small of back yards ( I am good but not THAT good ), city streets with power wires and traffic.... What if that was when the power died, the engine quit, the fuel pump died, or the ECM went into limp mode ( factory programming still has that mode for mutli failure detection ). My point is that it belongs in aviation, but with proper planning and correct installation. It is NOT as easy as ripping it out of the car/truck, and installing it in the plane as is. A proper electronic fuel injection aviation package must be engineered as a package into the plane. I believe Mark Langford went away from it for this reason, and I know from reading his manual that William Wynne did. It takes alot more know how of the system to package an aviation version properly than just cut and paste. Otherwise, I would already have done it!
Colin & Beverly Rainey Apex Lending, Inc. 407-323-6960 (p) 407-557-3260 (f) www.eloan2004cr.com crai...@apexlending.com
