Week 2

1.What is the firing order of a four stroke engine?
Its the way the cylinders ignite the air/fuel mixture. The energy that's left turns the crankshaft and is shared with the pistons. The pistons in a Four stroke engine need to have two revolutions to complete the cycle with the firing order in sequence so that there is a equal load on the crankshaft.

2.What is the difference between a S.I and C.I engine?
S.I : the spark from the sparkplug ignites the air/fuel mixture when the cylinder is at TDC.
C.I : Hot air is introduced to the cylinder on the compression stroke and at the top of the stroke fuel will then be introcduced to the hot air. This mixture then expands and ignites.

3.Is there any difference between a S.I and C.I piston if so what?
C.I pistons have a deep groove so that when air is compressed the fuel can be injected with the piston being larger so that it can handle more pressure.

4.What year was the diesel engine invented and by whom?
1897 by Rudolf Diesel
5.What is the purpose of the oil jet on the connectng rod, and where does it spray?
The purpose of the oil jet is to lubricate between the piston and the bore. The oil jet sprays oil onto the cylinder wall.

6.On the connecting rod where is the big end and little end?
Big End :  Connects to crankshaft
Little End : Connects to piston

7.What is the purpose of the thrush washers on the crankshaft?
Thrush washers stop unwanted movement. There is a hole on the thrust washer that lines up with the hole on the connecting rod. This is where oil travels throught and sprays the piston and the bore for lubrication.

8.On a diesel engine whats the difference between direct injection and a indirect injection type?
Direct injection: Fuel is simply injected directly to the combustion chamber. 
Indirect injection: Fuel goes to the prechamber. The prechamber is linked off the combustion chamber, the combustion chamber starts the prechamber and then the fuel spreads to the combustions chamber.
9.Explan the term valve timming?
The timing of when the valve opens and closes. It is controlled by the camshaft. The timing of the valves is important to be right so that the air/fuel mixture enters the combustion chamber so the exhaust exits.
10.Why do we have valve clearance?
Vakve clearance makes the valves open and close properly, its important that the clearance is correct because if there is too little gap the valve wont close completly and if the gap is to large the valve wont open to fully.