function of the crankshaft?
converts reciprocating motion of the piston and connecting rods to rotary motion, drives camshaft and engine accessories
where is the nose of the crankshaft?
at the front, mounting surface for crankshaft gear and vibration damper/hub
what are the journals of the crankshaft?
load bearing surfaces
what is throw in relation to crankshaft?
distance from centreline of main journal to centreline of the connecting rod journal
stroke is equal to two times the throw
ya
what is the web in relation to crankshaft?
connector for the main and rod journals to form the throws or crank arms
what is the flange in relation to crankshaft?
mounting surface for the flywheel, at rear of crankshaft
where are the oil passages on a crankshaft?
to the main bearings through passages in the cylinder block. they’re internal drillings
how are the throws of a crankshaft arranged?
so all cylinders will fire an even # of degrees apart
what is the firing order for an 8 cylinder v engine?
15 48 63 72
how is crankshaft rotation most commonly viewed?
clockwise from the front of the engine
on a six cylinder engine, how often would it have a cylinder firing in degrees of crankshaft revolution?
every 120 degrees of crankshaft revolution
what is the firing order for a 6 cylinder engine?
15 36 24
what are mating cylinders/running mates?
cylinders on the same stroke, ex. #1 and #6 cylinder would both be at TDC, one finishing the compression stroke, the other finishing the exhaust and starting intake
how do you find the running mates?
take the firing order, split in half, arrange the two halves one over top of the other. ex. 153624= 1/6, 5/2, 3/4
are there mating cylinders on a two stroke?
no as all the cylinders fire in one revolution
what are the symptoms of an unbalanced engine?
run rough and excessive vibration and stress on components, have reduced mechanical efficiency= loss of power output
what are inertia forces created by?
acceleration and deceleration of piston and connecting rod assembly from TDC to BDC
function of a flywheel?
store and release energy to reduce variations in speed of the crankshaft
function of a vibration damper?
counteract or oppose the twisting forces acting on the crankshaft to reduce torsional vibration
function of friction type engine bearings?
reduce friction between moving parts, support +maintain alignment of shaft or component, provide wear surface
what do thrust type bearings do?
get rid of endwise movement of crankshaft or camshaft
