|
| |
      
The Short Block includes all the parts within the
cylinder block itself which are not part of
another system; such as the lubrication ,
cooling system, or valve train. Generally, the short
block is the assembly which is
re-built during an engine overhaul.
Cylinder Block
The Cylinder Block is the basic part of the engine
that all the other parts of the engine are connected to.
 | It holds all of the engine's internal parts.
|
| It holds the engine and transmission in the frame.
|
| It gives the engine structural strength.
|
Materials:
Cast Iron;
| Most
common
|
|
Cheap, hard, long wearing , strong, easy to machine, quiet.
|
|
Heavy, and therefore, takes more power, and more fuel, to get it moving.
|
Aluminum;
| Is becoming more
common as the car manufacturers try to get better gas mileage.
|
| Use of aluminum
in the block causes the engine to be noisy, because aluminum doesn't deaden sound as
well as iron does.
|
3 Types:
High Silicon Alloy- Used by General Motors' Chevrolet division, in
the Vega, built from 1970 -1979. It had no sleeves at all, but the block was cast from a harder alloy of
aluminum to prevent the cast iron rings from wearing the cylinder walls.
It didn't work, the cylinder walls wore out anyway, and almost all Vega's burned oil prematurely.
Dry Sleeves- This is the most common type of aluminum block, and is
used by numerous
manufacturers. It uses a non - replaceable steel sleeve pressed into the aluminum
block for the rings to wear on.
Replaceable Sleeves- Used by large diesel engine manufacturers,
Volkswagen, in the Beetle, and Alfa Romeo; it allows the sleeve to be replaced along with the piston when
the engine is overhauled.
Servicing:
Taper;
Taper is caused by the rings wearing on the cylinder
walls. Wear is greater at the top of the cylinder, because:
Cylinder walls are lubricated by oil thrown off the connecting rod bearings, and not as much oil makes it up to the top of the cylinder as is at the
bottom.
Raw gasoline washes the oil off the cylinder walls when the engine is cold, especially in carbureted engines.
What oil does make it up as far as the top of the cylinder, gets burned
off on the power stroke.
This results in a tapered wear pattern on the cylinder
walls, with an un-worn area, called the ridge above the travel of the top ring. A quick
test of how much wear is on an engine, is if your fingernail catches on the ridge when you
run it up the cylinder, there is probably too much wear on the engine to just hone it, and
it must be bored out. Maximum wear for just
de-glazing, and installing new rings, is
.005". Any more wear and new rings will not seal; or they will seal, but will
wear out pre-maturely, or break. If there is more wear than .005", the block must be
bored out by a machine shop, and new oversize pistons and rings must be installed. Always
remove the ridge from the cylinder walls, before removing the pistons from the block.
Cracks
Cracks in the cylinder block, have two causes:
Freezing - water in the water jackets freezes, and the
resulting ice cracks the water jackets. If the cracks are not in a critical area,
sometimes they can be repaired with epoxy. If the block is made of aluminum, it can be
welded. It is much better to prevent freezing by the use of a suitable anti-freeze.
Stress- Stress cracks can not usually be repaired.
The block must be replaced.
Pistons
Material:
Cast Aluminum-
- Molten aluminum is poured
into a mold, the aluminum cools, and hardens. The casting is then machined. Cast aluminum
pistons have a crystalline structure which is not as strong as that of a forged piston. Steel bands are inserted in the mold when the piston is cast, to control expansion of the
skirt area to be parallel to the wrist pin, which allows piston to cylinder wall clearance
to be set closer, and, therefore, a quieter engine with less piston slap.
Forged Aluminum-
- A solid slug of aluminum is
pressed, very quickly, and with a great deal of force into a die. The resulting forging is
then machined to shape. Forged pistons have a grain structure rather than a crystalline
structure, this makes them much stronger, and able to take more punishment. For many years forged pistons were used in racing and extreme high performance street engines, but
recently have fallen out of favour, because of their relatively heavy weight. Forged
pistons also cause the engine to be more noisy because wider piston to wall clearances,
required by their lack of steel bands, cause more piston slap. Forged pistons should be
considered for racing purposes only, if at all.
Hyper-eutectic ( high pressure ) Cast Aluminum
- A good compromise between forged,
and cast pistons, is casting using high pressure. It has relatively light weight, steel
expansion bands, and is just about as strong as forged pistons. Hyper-eutectic pistons are
very expensive.
Why is Light Weight so Important?
- One of the biggest dis-advantages
of the reciprocating piston engine is the fact that a great deal of energy is wasted by
stopping and starting the piston at TDC and BDC. The crankshaft can be turning at 7000
RPM, but every time the piston is at TDC, it comes to a complete stop for a short period of time. In fact, at 3000 RPM, the piston is stopped at TDC, accelerates to the equivalent
of 60 MPH one and a half inches down the cylinder, and then stops again at BDC.
Acceleration can be measured in gravity, or " G force ". We weigh what we weigh
on earth at one gravity. A fighter pilot, in an F-16, or F-18, in a tight turn, can pull
as much as 8 G's without blacking out. If that pilot weighed 200 lbs., standing on the
ground, he would weigh the equivalent of 8 times his own weight, or 1600 lbs., in an 8 G
turn; in fact, the reason he blacks out at 8 G's, is his heart is no longer capable of
pumping his blood to his brain, because the blood weighs so much, and the brain shuts down. A piston pulls over a thousand G's at 3000 RPM, so if it weighed 300 grams at rest;
it would weigh the equivalent of 300,000 grams, or 300 kilograms at only 3,000 RPM; a
relatively low engine speed. Increase the weight of the piston, and the stress doesn't
just increase by the amount of the weight, but by a thousand times as much. So if a forged
piston is a little heavier, all the rest of the engine parts, such as the connecting rods,
wrist pin, rod bolts, crankshaft, etc; all have to be made stronger too, to keep the engine from coming apart.. A great deal of energy is wasted in a reciprocating piston
engine due to this effect. A rotary engine, which doesn't have a piston which stops and
starts, makes much more power for its' size.
- Aluminum melts at 1,200 degrees
Fahrenheit. The burning gasses above the piston, have a temperature of as much as 4,000
degrees Fahrenheit. So what keeps the piston from melting? Oil thrown up onto the
underside of the piston takes away some heat, as does contact with the relatively cool
cylinder walls, but pistons routinely run at temperatures as
much as 600 degrees
Fahrenheit.
- Pressure generated on the power
stroke, by the burning gasses to push down the piston down, are around 1000 PSI. A
Chevrolet 350 V-8, or Ford 5.0 liter V-8, has a 4 inch bore. The area of the top if
one of its' pistons is 12.56 square inches. This would make around 6 tons of force on the
top of each of its' pistons.
Piston Parts:
Piston Dome, (or Head, or Crown)
- The top of the piston is called
the dome, head or crown. This is the area which directly contacts the flame, and takes the
brunt of the forces on the piston.
- The dome comes in many shapes.
High performance engines use a piston with a high dome, which raises the compression
ratio.
- Flat topped pistons, some having
valve relief's to prevent valve to piston interference, are used in stock factory engines
with 8 -10 : 1 compression ratios.
- Dished pistons are used by the
manufacturers to lower compression ratios. This is done to lower flame temperature, and
therefore, oxides of nitrogen (NOx). Dished pistons are also commonly used
in turbocharged engines to prevent detonation, and because the turbo is already
providing the engine with compression.
Ring Section
- The ring section is about
.015" smaller than the skirt, so it never really touches the cylinder walls, but the
rings obviously do. The ring lands are the top and bottom of the ring grooves, and
must be completely smooth for the rings to seal on them. They must not have any nicks,
gouges, or carbon on them, or blowby gasses will leak around behind the ring and the
engine will lose compression. There are oil return holes, or a oil slot, in the bottom
ring
groove, to allow oil to return to the sump through the piston.
Piston Skirt
- The skirt is the only area
of the piston which contacts the cylinder walls. The clearance between the piston skirt,
and the cylinder walls must be very precise, and depends on the type of pistons used in
the engine. Aluminum and iron have different expansion rates. Aluminum, because it is not
a very dense metal, takes on heat very easily, and gives it away again very easily. Iron,
on the other hand, is very slow to heat up, and remains hot for a long time. If piston
expansion was not controlled somehow, the piston skirt would grow to be larger than the
cylinder its' going up and down in, and obviously, the engine would seize up. Cast
pistons, because their expansion is controlled with a band of steel. can have a relatively
small piston to wall clearance of .003"-.004". These bands are placed in the piston mold before the molten aluminum is poured in, and are around the wrist pin. This
makes piston expansion parallel to the wrist pin only. The piston skirt is then ground to
be oval shaped, or "Cam Ground", so there is the same clearance between the
skirt and wall when the engine is hot, as when it is cold. There is, however,
more area
when the engine is hot. Pressure, and therefore wear is much greater when the engine is
cold, but the engine is still quiet, with no piston slap.
- There is no way of putting
expansion bands in a forged piston, so there is no expansion control at all. This means
more piston skirt to cylinder wall clearance must be left in an engine with forged
pistons. Piston to wall clearance must be from .008" to .010". This means an
engine with forged pistons will have noticeable piston slap when the engine is cold, but
since forged pistons are used almost exclusively in race engines, and racers don't care
how the engine runs when it's cold, this doesn't matter. To your average car owner,
though, this would be unacceptable.
Wrist Pin or Piston Pin
What does it do?
- The wrist pin connects the piston
to the connecting rod, and allows the piston and rod to flex back and forth in one
direction only. Transmits entire force of the power stroke to the connecting rod so it
must be strong.
Material
- The wrist pin is made of thick
wall, case hardened, steel tubing. In a round piece of steel, all the strength comes from
the outside 1/8th inch. The part in the center is just along for the ride. Since the wrist
pin is part of the reciprocating weight, it is jut as important for it to be light, as it
is for the piston to be light; so tubing is used instead of solid stock. Thick wall steel tubing gives maximum strength, with minimum weight. "Case Hardening" is the
hardening of the outside .0003" of the pin. The reason this is done is because it
retains the toughness of the steel, while the surface is extremely hard. Heat treating for
hardness would make the part brittle, like a file; hard, but not tough. Heat treating for
toughness ruins the hardness; it would be tough, but not hard; like a spring.
Three Types:
- Somehow the wrist pin must be kept
from coming in contact with the cylinder walls. It must be locked in place somehow. This
has been done in three different ways over the years.
1. Piston Locked
- The wrist pin is locked in place
by the piston, either with a lock bolt, as is shown in the drawing, or by an interference
fit. An interference, or press fit, is where the hole in the piston that the pin goes into
is actually about .0001" smaller than the pin, and the pin is installed either by
using a hydraulic, or arbour press; or by heating the piston. The bearing surface is in
the rod, and so the small end of the rod must have a bushing installed, which was usually
oiled by "rifle drilling" a hole up through the beam of the connecting rod from
the rod bearing. This system wore out quite quickly and was expensive to produce. It had a
relatively small bearing surface in the small end of the connecting rod.
2. Rod Locked
- This more modern method is
still used by most north american manufacturers to locate the wrist pin in place. It can
use a lock bolt in the rod to hold the pin in place, but more commonly uses a press, or
interference fit to retain the pin. This means that the bearing surface is now in the
piston. The bearing area is twice as big, to last twice as long, and whenever the pistons
are changed, the pins are changed too. The only disadvantage of
the rod-locked type, is
that a press is required to disassemble it, and either a press, or heat is required for
assembly.
Full Floating
- The full floating type of wrist
pin retention is probably the best of all. The pin is kept in place with either a plastic
button in the end of the pin, or more commonly, a snap ring. This makes bearing surfaces
in the connecting rod, and the piston; and gives three times the bearing surface of the
piston locked type. The full floating type is also easy to disassemble and assemble. All
you have to do is remove the snap ring. No press is required. Always
replace the circlips,
or buttons, on re-assembly. Never try to re-use previously used clips, or buttons.
Connecting Rod
What Does It Do?
- The connecting rod connects the
piston to the crankshaft. All the power absorbed by the piston travels to the crankshaft
through the con.rod; so it has to absorb a compression force of around 6 tons. All the
inertia of the flywheel, or the other cylinders is transmitted back to the piston through
the so it has a tension force of around 2 tons.
- The connecting rod is
reciprocating weight, and so, must be extremely strong and light. All the connecting rods
in the engine must be very close to the same weight; and each end of each connecting rod
must be close to the same weight.
Big End
Beam
Small End
Big End
- The big end is split to go around
the rod journal of the crankshaft, and then bolted back together with extremely high
quality 150,000 p.s.i. tensile strength connecting rod bolts. These rod bolts must be
torqued on engine assembly. There is a number pad where the cylinder number is stamped on both the rod and rod cap, to make sure they go back together the same way.
Beam
- The center part of the rod is
called the beam, and has an "I" beam cross section, for maximum strength, and
lightest possible weight.
Small End
- The small end has a hole for the
wrist pin to go through.
Materials
- Forged steel is used in production
car engines. Forged aluminum is used in some racing engines. A set of racing, forged
aluminum rods will set you back over $1,000.00. Forged titanium connecting rods
are used in some mega-buck race cars. A set of titanium rods will cost you
around $5,000.00
Crankshaft
What Does It Do?
- The crankshaft converts the
reciprocating (or up and down) motion of the piston to rotary (or round and round) motion,
needed to turn the drive wheels. It creates a twisting force, called "Torque".
The crankshaft must be very precisely balanced, or the engine would shake itself to
pieces.
Parts:
Main Journals:
- The main journals are the machined
surfaces that turn in the engine's main bearings, that allow the crank to turn in the
block. They must be very precisely machined to allow between .0015" and .0022"
of oil clearance with the engine's bearings.
Connecting Rod Journals, or Crankpins
- The rod journals are
machined surfaces that allow the crank to turn inside the rod bearings. Like the main
bearings they need between .0015" and .0022" oil clearance.
Counterweights
- The counterweights off-set, or
balance the weight of the piston and connecting rod , especially in inline, or straight
engines, to a lesser extent in Vee-type engines, and are not required in Flat, or
Horizontally Opposed engines, because the weight of the pistons and rods on one bank,
offsets that of the other.
Oil Passages
- Oil travels through oil passages
in the crankshaft to lubricate the rod bearings, from the main bearings.
Flange
- The flange on the rear of the
crankshaft is for mounting the flywheel.
Materials
Forged Steel
- Forged steel is probably the
strongest material used to make crankshafts. It is a more expensive manufacturing process
than casting. Most manufacturers have switched to cast crankshafts, because of the
expense. Forged cranks are probably not necessary for the average street engine.
Cast Iron
- By far the most common material
used for crankshafts, is cast iron. It is hard, cheap, strong, and is easy to machine.
Servicing
- The rod and main bearings are
designed to be a "sacrificial part". They are there to protect the crankshaft
from wearing out. If the soft material on the inside of the rod or main bearings wears
out, the steel shell of the bearing contacts the crank, and the rod and main journals
wear. This causes excessive oil clearance between the crankshaft journals and the
bearings, which results in low oil pressure, knocking, and excessive oil consumption. When
the engine is dis-assembled, check the rod and main journals for scratching and scoring. If they are worn, the crankshaft must be taken to a crank grinder, who will grind the
journals "Undersize", and undersized bearings must be installed. Oil clearance must
be maintained at .0015" to .0022". If the journal was ground .010"
undersize, then .010" undersize bearings must be installed. A crank grinder will also
check the crankshaft for cracks, and straightness.
Flywheel
What Does It Do?
- The flywheel stores energy on the power
stroke, and keeps the engine going on its' non-power strokes. The heavier the flywheel is,
the more energy it stores, more of the power the engine puts out would go to spinning the
flywheel, and less would go to pushing the car forward. Engines with heavier flywheels are
not designed for acceleration, but would be easier to drive, because they would not stall
as easily. For example; a tractor, or big truck would have a heavy flywheel, but a drag
race car, motocross bike, or road race car would have an extremely light flywheel, for
maximum acceleration. A street car would be a compromise between the two.
- The flywheel also has the friction
surface for the clutch on one side.
- The flywheel is bolted to the rear
end of the crankshaft on the flange. Its' bolts must
be loctited, and torqued to
manufacturer's specifications. It must also be very precisely
balanced, or it would shake
the car to bits. After a flywheel has been lightened, it must be
re-balanced, and it is a
good idea to use a scattershield. If the flywheel ever came apart,
it would literally rip
the car in half, and probably kill the driver.
- Sometimes the timing marks are
located on the flywheel, especially in front wheel
drive cars.
Materials
- The flywheel is probably made of
cast iron, but in race cars sometimes aluminum is used, but the clutch surface would be
faced with steel.
Harmonic Balancer
What Does It Do?
- The harmonic balancer absorbs the
torsional vibrations of the crankshaft. It basically
makes the crankshaft last longer. It
is a small flywheel on the front of the crankshaft that
absorbs and smoothes out the power
pulses of the crankshaft.
- The balancer is usually pressed on
to the crankshaft snout, and keyed to only go on one way. If it needs to be removed, a
special puller which pulls on the inside hub must be used The timing mark is usually
located somewhere around the outside of the balancer.
Piston Rings
What Do They Do?
- The top two rings seal the
compression gasses in the combustion chamber. The bottom
ring scrapes the oil off the
cylinder walls, and it returns through the oil return slot in the piston, to the sump.
Materials
- Cast iron is still the most common
material used for the two compression rings. Steel is almost always used for the oil
control ring.
- Ductile iron is another alloy of
iron which is becoming more popular. It is just as hard as cast iron, but is less brittle,
and so will take more punishment.
- Molybdenum filled rings are also
popular. These iron rings have a channel in their face,
which is filled with molybdenum.
The moly breaks in to the cylinder walls almost immediately on start up.
- Chrome plated rings are used in
many off-road applications such as tractors. They are
very hard, and take a long time to
break in.
How Do They Work?
Compression Rings
- Compression rings are the two top
rings. They work by, the compression gasses leaking around behind the ring and forcing it
into the cylinder walls.
- This requires:
that there ring be spring loaded to force itself into the cylinder
wall.
that the ring lands be free of any nicks, or gouges; so the ring sides
can seal on them.
that there be oil on the cylinder walls. Oil seals rings.
Oil Control Rings
- The bottom ring scrapes most of
the oil off the cylinder walls, and it returns to the
sump through the oil return holes in
the piston. Some oil must be left on the cylinder
walls to lubricate the compression
rings, and to make them seal the cylinder.
Servicing
Cylinder Wall Preparation
- After many thousands of miles, the
cylinder walls become polished, or glazed, by the rings wearing on them. The cylinder
walls must be properly prepared for assembly by honing, or de-glazing the walls with a
cylinder hone, or glaze breaker. You want to use a 1/2 inch drill with the hone mounted in
it; lubricate the walls with engine oil; move the hone up and down as it rotates in the
cylinder. Continue for about thirty seconds. There should be a "cross hatch"
pattern on the walls when you are done. Continue until all cylinders are done.
- The entire block, especially the
cylinders must now be cleaned of all grit from the honing process. This is done by washing
the entire block with HOT, soapy water, and a brush. Scrub the surfaces of the cylinder
walls particularly well, until there is no chance of any honing grit in the cylinders. Any
grit will make its' way into the engine bearings and wear them out. When the walls are
clean, wipe them out with paper towels. Clean paper towels wiped into the cylinder walls
should come out clean. When the walls are clean and dry, wipe them with an oily rag to
protect them from rusting.
Check Ring End Gap
- Take one of the new compression
rings out of the box and push it down in one of the cylinders with the head of one of the
pistons. Check the end gap of the ring with a feeler gauge. The ring end gap should be
.003" to .005" per inch of cylinder diameter. This would make the gap for an
engine with a 4" bore, from .012" to .020". If the gap is too small,
when the engine gets hot and the rings expand, the ends come together, and the ring
breaks, removing ring tension, and therefore, there is no compression. If ring gap is too
wide, blowby gasses leak through the ring gap, into the crankcase, and causes pollution.
Install Rings
- When you install the rings on the
pistons, use a ring expander tool, rather than your fingers.
Off-set End Gaps
- Use clean engine oil to
lubricate the rings, wrist pin, rod bearings, and piston skirts, before you put the
pistons in. Lastly, before you install the pistons in the engine, off-set the ring gaps
180 degrees. This is done to prevent leakage past the rings through the ring end gaps. If
the gaps are lined up, it is very easy for the blow-by to leak past the rings. If the gaps
are off-set, the blow-by can leak through one gap, but must go all the way round to the
other side of the piston, to get down through the second ring gap.
Installing Pistons
- Use rod bolt protective boots, or
a pair of old spark plug boots, to keep from marking the crankshaft. Next install the ring
compressor on the piston. Make sure the right piston is installed in the right cylinder,
the right way round. There is usually an arrow on the top of the piston to indicate the
front of the engine. Seat the ring compressor against the block by tapping it with a
hammer, then push the piston and rod assembly into the cylinder with the butt of a hammer
handle.
..O.K., ...so now you think you know it all. Take the self test!
The Short Block
The next six questions refer to the above
drawing.
The wear in the above worn cylinder was caused by what
wearing on the cylinder walls?
a) piston rings
b) piston
c) wrist pin
d) oil
If the difference between A and B is greater than
.005", the
engine must be _______________ and oversized pistons and rings installed.
a) honed
b) bored
c) ground
d) re-surfaced
An engine with less than .005" difference between A and B can be
____________ and standard sized rings installed.
a) deglazed
b) bored
c) ground
d) re-surfaced
Rather than having to deal with
cracks, it is much better to prevent cracking by the use of
__________________.
a) Anti freeze
b) Bars leaks
c) Aluma seal
d) Water
Pistons
Place the correct letter from the above drawing by the
right name for each part:
Wrist pin hole: A
B C
D E
F G
Ring Land
A B
C D
E F
G
Ring section: A
B C
D E
F G
Piston Skirt A
B C
D E
F G
Dome or Crown A B
C D
E F
G
Ring groove A
B C
D E
F G
Oil return slot A
B C
D E
F G
What is the only part of the piston to contact the cylinder walls?
a) Ring
area
b) Dome
c) Pin
boss
d) Skirt
Piston to cylinder clearance should be approximately how
much?
a) .0015"
b) .004"
c)
.040"
d) .120"
Al
says that piston to wall clearance should be checked between the wrist
pin and wall. Bob says that piston to wall clearance should be checked
between the skirt and wall. Who is correct?
a) Al
b) Bob
c) Both
d) Neither
Piston expansion is controlled by putting a band of
what in the piston.
a)
Steel
b) Aluminum
b)
Magnesium
d) Chromium
What is the advantage of a forged piston
over a cast one?
a)
stronger
b) lighter
c)
quieter
d) cheaper
Crankshaft
The crankshaft converts the a) rotary b) reciprocating motion of the pistons, into
a) rotary b) reciprocating motion needed to turn the wheels.
A crankshaft from a vee or inline engine has ___________
opposite
the throws, to prevent vibration.
a)
counterweights
b) balancers
c) vibration
dampers
d) flanges
A crankshaft with scratches in the journals must be ground and
_____________ bearings installed.
a)
new
b) oversize
c)
undersize
d) Sealed Power
When an engine is disassembled or assembled,
what must be put on the connecting rod bolts to prevent damage to the crank
throws?
a) protective
boots
b) oil
c) Michigan Bearing
Guard d)
grease
Connecting Rod
The big end of the rod is called the _______________
The small end of the rod is called the _________________
Why does the center section of the rod has an "I" beam cross section?
a) high
strength
b) light weight
c) both of the
above
d) none of the above
How many bolts fasten the connecting rod cap to the rod
itself?
a)
one
b) two c)
three d)
four
When assembling an engine, it is important to measure
bearing oil clearance. Normal bearing oil clearance will be:
a) .0015"-
.0022"
b) .003" - .006"
c) 1/8"-
1/4"
d) very small
A light flywheel would be found in what type
of engine?
a) race
car
b) tractor
c)
truck
d) street car
A heavy flywheel would likely be found in
what type of engine?
a) race
car
b) tractor
c)
truck
d) street car
Piston Rings
Of the three rings the compression rings are the two ________
ones.
a) best b)
most
expensive
c) most
important
d) top
Compression rings use______________ pressure to seal the cylinders.
a)
compression gas
b)
spring
c)
oil
d) atmospheric
When re-ringing the engine, the cylinder walls must be ____________,
so the new rings will break in properly.
a)
polished
b) sanded
c) bored
d) de-glazed
Ring end gap should be at least .004"/inch of cylinder diameter. If the
gap is too small the rings will ____________ when the engine gets hot.
a) not
seal
b) break
c) wear out prematurely d) rub
If the ring end gap is
too large the rings will _______________.
a) not
seal
b) break
c) wear out prematurely d) rub
Oil returns through __________in the piston to return to the sump.
a) oil return holes or
slots
b) ring lands
c) oil
filters
d) drain plugs
The pistons, rings, pins, and cylinder walls are lubricated by oil which
leaks from and is thrown off of the _____________ .
a) rod
bearings
b) wrist pins
c) oil
pump
d) oil filter
Top
|
