Engine Fundamentals Flashcards
What is Cylinder displacement?
Volume of cylinder at top dead center and volume at bottom dead center.
What is compression ratio?
How much air/fuel mixture will be compressed at Top Dead Center (TDC) vs Bottom Dead Center (BDC).
What is ‘Work’ ?
When force moves mass a specific distance.
What is gear ratio?
Driving Gear over Driven Gear
What is Horsepower?
The rate of which Torque is Produced
Who first calculated Horsepower?
James Watt.
What is the Atkinson Cycle?
It delays intake valve open to let mixture escape back into intake manifold.
What are Intake Valves made up of?
Chrome, Nickle or Tungsten Steel.
What are Exhaust Valves made up of?
Nichrome, Silicon-chromiun or Cobalt chromium Alloys.
What does OHC mean?
Overhead Camshaft Engine.
What are Main Caps?
They hold the main crankshaft bearings in place.
What are the Piston Strokes in a 4-Stroke Engine?
Intake, Compression, Power and Exhaust.
What is leakage past the piston rings called?
Blowby.
What is Bearing Spread?
The parting face is slightly larger then the bearing bore.
What is the best way to describe piston slap noise?
A Hollow Bell like noise.
What test can be done to pinpoint the cause of a low cylinder compression?
Cylinder Leakage test.
What is Piston slap?
Noise made by the piston when it contacts the cylinder wall.
During a cylinder leakage test, where would you hear air if the Intake Valve is leaking?
Throttle Plate.
During a cylinder leakage test, where would you hear air if the Piston Rings were worn?
The oil fill port or dipstick tube.
During a cylinder leakage test, where would you hear air if the Exhaust valve was leaking?
Exhaust Pipe.
During a cylinder leakage test, where would you hear air if the Head Gasket was blown?
Radiator.
The Stroke of the Piston equal to ___ the Crankshaft Throw.
2x
What is Thermal Efficiency?
How much of the heat formed during the combustion process is available as power from the engine.
As an engine compression ratio increases, what should happen to the octane rating of the gasoline?
It should increase (to avoid detonation).
What Engine type has the highest compression ratio?
Diesel Engine.
What engine component is responsible for closing the intake and exhaust valves?
springs
What is Tappet Noise?
Noisy Valvetrain Components.
How many degrees of crankshaft rotation are required to complete a four-stroke cycle in one cylinder?
720
Which V-type engine valve train design may use four camshafts?
DOHC
SOHC V-8 engine has how many camshafts?
2
When removing a cylinder head, which order should the bolts/nuts be loosened?
In the reverse order of assembly.
what is the max allowable warpage on a V6 head?
0.003 inches.
what is the max allowable warpage on a V8 head?
0.004 inches.
what is the max allowable warpage on a I6 head?
0.006 inches.
A free wheeling overhead camshaft engine is a _____________?
non-interference engine.
What are Integral valve guides are reconditioned by?
Installing Bronze guide liners or by
Reaming the guide (for an oversize valve stem).
What is the typical interference angle used in gasoline engines?
1 degree.
Multiple valve springs (dual springs) generally have both coils in what direction?
Wound in opposite directions.
When should a valve be discarded?
When it has damaged keeper grooves, is cracked or bent.
What is the cause for blue smoke that occurs after starting the engine?
worn valve seals or guides.
Where should the piston be when a Cylinder Leakage Test is done?
Bottom Dead Centre on Exhaust Stroke.
What 3 things should Valve Springs be checked for?
Tension, free height and squareness.
Which Valve is larger?
Intake Valve.
What Engine type does not have Pistons?
Rotary.
Engine Displacement is measured in ________ .
CC or Liters.
What is the Maximum Valve margin clearance?
1/32 of an inch.
How much pressure does a Cylinder need to hold?
1000-1500psi
What is the Formula for calculating displacement?
pie r2 (half the bore) X stroke X # of cylinders
