The engines we are working on: 1-3-4-2
2.What is the difference between a S.I and C.I engine?
SI - Fuel ignited by a spark created by a spark plug
CI - Fuel ignited by heat in the cylinder created by a glow plug and the compression of the fuel and air.
SI - Uses petroleum fuel
CI - Uses diesel fuel
SI - Compression = 6-10 psi
CI - Compression = 16-20 psi
SI - During suction stroke fuel is allowed into the combustion chamber
CI - Towards the end of the compression stroke the fuel and air mixture is injected into the combustion chamber and almost imediately ignites due to diesel having a lower combustion temperature.
CI - heavier due to it needing to handle higher preasures in the combustion chamber than the SI
SI - Produces higher speeds
CI - produces lower speeds
SI - pistons
3.Is there any difference between a S.I and C.I piston if so what?
The C.I piston needs to create a larger compression as there is no spark to ignite the fuel, therefore has a different shaped piston
CI SI
4.What year was the diesel engine invented and by whom?
1892 by Rudolf Diesel, German Inventor
5.What is the purpose of the oil jet on the connecting rod, and where does it spray?
It sprays oil onto the walls of the cylinder with every revolution of the crankshaft. It's purpose is to lubricate the piston as it moves up and down the bore and also the piston pin.
6.On the connecting rod where is the big end and little end?
The big end is where it is conected to the crankshaft. The small end is where it connects to the piston with the piston pin.
7.What is the purpose of the thrust washers on the crankshaft?
To cut down on end float.8.On a diesel engine whats the difference between direct injection and a indirect injection type?
Direct injection the fuel is injected straight into the combustion chamber.
Indirect injection the fuel is injected into a seperate chamber.9.Explan the term valve timing?
At which point each valve is open in respect to the other and position of the piston.
A couple of terms are:
Lead: intake valve opens before TDC and exhaust valve opens before BDC.
Lag: intake valve closes after BDC and exhaust valve closes after TDC.
Overlap: intake and exhaust valves are both open for a few degrees around TDC of the exhaust stoke.
10.Why do we have valve clearance?
When the valve train gets hot, it expands. The valve clearance gives it room to do so. If this wasn't there the valve wouldn't shut properly and may cause fuel to leak or the valve to burn.
