We have three more weeks, Final Exam is on May 18th!
The last chapters are 45 Cooling systems and 49 Lubrication. So the ASE questions to help you with the quiz. The take away from my ramblings is that the cooling system removes excess heat energy from the engine. This starts in the cooling jackets and uses the water pump to transport the hot antifreeze to the radiator, which releases the heat outside of the engine. The cooled antifreeze is transported back to the engine to absorb heat. Pressure and antifreeze content raise the boiling point of water, increasing the amount of heat it can absorb and release, and also increasing combustion efficiency. Radiator efficiency is affected by air flow, surface area, and the difference in temperature in the air flow and surface area.
Next Saturday will be set aside for quiz make-ups. If you cannot make it on the 4th, I will extend this to the 11th, but it leaves yo with less time until the 18th. I have given you lists of quizzes that are missing. If you don’t know, then text me at 714-348-1376.
I am giving you all the chance to retake one quiz at no penalty.
Unless otherwise specified, for the missing quizzes, there will be a ten percent drop in quiz score, but it is much better than zero. Some of you may not pass this class due to missing assignments and quizzes. I strongly encourage you to study and make up the quizzes. This will improve your grade and you will get correct answers. The final will come from these quizzes and a few from the midterm assignment.
EXTRA CREDIT! I’m working on this now, check back!
Read Chapter 40 fuel systems and answer the ASE questions at the end. On the graphics on page 697 shows the evolution of fuel delivery starting from the bottom diagram up. Carburetor systems were low pressure, around 3 PSI (Pounds per Square Inch) and typically had a mechanical pump attached to the engine. Because of low pressures drawn on the fuel lines from the tanks, the fuel could boil and suffer vapor lock in the lines. Fuel Injection arrived to atomize fuel delivery with a fine spray. It needed higher fuel pressures, 35-45 PSI, so the fuel pump was relocated back to the fuel tank to avoid low pressure vapor lock. Single Point Injection used one or two large fuel injectors that were common to all cylinders at the throttle body (cheap and not very effective), and Multi-Point Port Injection (superior), using several injectors, one at each cylinder, spraying right before the intake stroke. Direct Injection is the latest and greatest fuel system for gasoline engines. These use an in-tank pump to deliver fuel (~50 PSI) to an engine mechanically driven high pressure pump. The Super-fast injectors and dangerously high pressures, 750 to 3,000 PSI, can inject fuel directly into the cylinder during compression and power stroke for a more versatile, controlled, and efficient fuel burn. FYI, Diesel engines, by nature, have always used direct injection since the beginning of time.
Read Chapter 45, Exhaust systems and answer the ASE questions at the end.
Please read Chapters 34 (Ignition systems) and 39 (Fuels and systems), and complete the ASE questions in the back of each chapter. There will, of course, be a quiz.
It’s time to start thinking about how our engines work and start putting them back together. Our teams need to work together as a whole to get all 6 engines running.
You’re all doing great on the team work exercises! For the next class, study chapters 13, 14, and 15, and complete the ASE type questions at the back of each chapter. Be prepared for a quiz on those chapters. If you were not prepared for the last quiz, you now have six chapters due, 11 through 16 with the ASE questions and two quizzes. Have a great week!