6. Bore Size
• The diameter of the
cylinder
• Measured in inches
or millimeters
7. Stroke
• How far the piston
moves from TDC to
BDC
• Equal to twice the
crank radius
8. Compression Ratio
• Ratio between the cylinder
volume with the piston at
BDC and the volume with
the piston at TDC
• Compression ratio of our
engines are approximately
a 16:1 (non-ACERT) and
18:1 (ACERT)
9. Displacement
• Engine size is
expressed in liters
or cubic inches
Displacement = (3.14 X B 2 ) X Stroke X No. of Cyls.
4
10. Horsepower
• Horsepower is the rate of doing work (how quickly a force is
applied through a distance)
• Horsepower can be expressed in pound feet per second
• 1 horsepower = 550 lb/ft per second
= 33,000 lb/ft per minute
11. Engine Model Numbers
• 3208 Engine:
3200 = Engine Family & Relative Size
• (3000, 3200, 3300, 3400, 3500, 3600)
• 08 = number of Cylinders
• Depending on engine family, could
be 04, 06, 08, 12, 16, 18, or 24
12. Engine Model Numbers
• 3116 Engine
3100 = Engine Family
• 11 = 1.1 liters per cylinder, so:
• 3126 has 1.2 liters per cylinder
• 3176 has 1.7 liters per cylinder
• 6 = number of cylinders (4 or 6)
13. Engine Model Numbers
• C-10, 10 liter truck engine
3176C is used in all other applications
• C-12, 12 liter truck engine
3196C is used in all other applications
• C7 replaced the 3126 engine
• C-9 replaced the 3306 engine
On-Highway & D6
14. Engine Model Numbers
3406 Engine
• 3406E was a 14.6 liter engine until 1998
• In 1998, 3406E was 14.6 or 15.8 liter for truck
• 3456 was the 15.8 liter in any non-truck application
• In 2000, 14.6 liter and 15.8 liter became C-15 and
C-16 for truck, industrial applications
• In 2003, 15.2 liter truck is ACERT C15
15. 3000/3100 Series Features
• Dry Sleeve/Parent Bore
Parent Bore – 3116/26, C7,3208
Dry Sleeve - 3054 3054
• One piece block assembly
• Light weight with high
horsepower to weight ratios
3126B
16. 3000 Series - Service Strategy
• Current Serviceability
Components only - 3003, 3013, 3024, 3034
Piece Parts - 3046, 3054, 3056, 3066
Reman as volume/need dictates
• Rebuild Strategy
3003 - 3034, expected engine life equals machine life
3046 - 3066, limited rebuild opportunity
3003 3013 3024 3034
17. C6.6 Series Features
using ACERT™ Technology
C6.6 Replaces the 3056E
• 1.1 Liter per Cylinder, Inline 6
• 4 valves per cylinder
• Cross Flow heads
• Fully Electronically Controlled
• Common Rail Fuel system
C6.6
• Sculpted Block design reduced noise
18. Cross Flow Cylinder Heads
• Cross flow design and
refined port geometry
Improved breathing
Reduced pumping loss
Better combustion
19. C7 Series Features
using ACERT™ Technology
C7 Replaces the 3116, 3126
• ADEM A4 Electronic Control Module
• Cylinder block – increased tensile strength
• HEUI fuel system
• Cross Flow heads
• Turbocharged and Air to Air aftercooling
C7
20. 3100 & C7 Series - Service Strategy
• Current Serviceability
Piece Parts For All
• Rebuild Strategy
Cost effective rebuild for all
models
Reman components and
limited short blocks, bare
blocks, and piston packs
available
3100
21. 3300/3400 Series Features
• One piece block
• One piece cylinder head
• Replaceable valve guides and seats
• Caterpillar fuel system
• Replaceable wet cylinder liners
• Roller cam followers and steel camshaft
• Totally hardened forged steel crankshaft
3400 HEUI
22. C9 Series Features
using ACERT™ Technology
C9 Replaces the 3300
• ADEM A4 Electronic Control Module
• 8.8 liter (537 cu in)
• HEUI fuel system C9
• Cross Flow heads ( 4 valves per cylinder)
• Turbocharged and Air to Air aftercooling
• Improved block and head material strength
• Mid-supported liner
• Integral oil cooler
• Reduced weight, leaks and engine width
23. C11/C13 Series Features
using ACERT™ Technology
C11 Replaces the 3176, C-10
C13 Replaces the 3196, C-12
C11
• ADEM A4 Electronic Control Module
• MEUI fuel system
• Cross Flow heads
• Turbocharged and Air to Air aftercooling
C13
24. C15/C18 Series Features
using ACERT™ Technology
C15 Replaces the 3406E, C-15
• ADEM A4 Electronic Control Module
•Variable injection timing
•Controls quantity of fuel
•Optimizes fuel pressure
•Transient control for both speeds and loads C15
• MEUI fuel system
• Cross Flow heads
• Turbocharged and Air to Air aftercooling
25. C27 Series Features using ACERT™ Technology
• C27 replaces 3412
• Two single overhead cams
• Gear-train for cams moved to back
Reduces noise & vibration
• Tight system tolerances - pistons & liners
More complete fuel combustion
Reduced blow-by
Fewer emissions
• New block eliminates bends/turns
to improve airflow
• Proven MEUI fuel system
• ADEM™A4 Controller
• Engine oil & filter changes
increased to 500 hours under
most operating conditions
Used on D10T, 773F, 775F
26. C32 Series Features using ACERT™ Technology
• C32 replaces 3508B
• Newly designed block adds
structural strength
• Cross flow cylinder head delivers
improved air flow
• Increased compression ratio
of 16.5:1
• Proven MEUI fuel system
• ADEM™A4 Controller
• Engine oil & filter changes
increased to 500 hours under Used on 777F & D11T (fall 07)
most operating conditions
27. 3300/3400 C7- C32 Series - Service
Strategy
• Current Serviceability
Piece parts and sub-
components for all models.
• Rebuild Strategy
Cost effective rebuild for all
models
Reman components, short
blocks, long blocks and
engines available
3406
28. 3500 Series Features
• One piece high strength cast engine block
• Individual cylinder heads
• Four valves per cylinder.
• Self aligning roller cam followers.
• Oil cooled pistons
• Unit injectors at 20,000 psi
3500B
• Caterpillar fuel system
29. 3500 Series - Service Strategy
• Current Serviceability
Piece parts for all
• Rebuild Strategy
Cost effective rebuild for all models
Reman components, short blocks,
long blocks and engines available
3500 Machine
31. Engine Build Locations
Build Location Engine Models
Peterborough, England 3011 3013 3024 3034 3054 3056 C1.5 C2.2 C6.6
Sagami, Japan 3044 3046 3064 3066 3304 3306
Gosselies, Belgium 3116 3126 C7 C9
Greenville, South Carolina 3126 C7 C9
Griffen, Georgia 3408 3412 C27 C30 C32
Mossville, Illinois 3406 3456 C-10 C11 C-12 C13 C15 C-16 C18
Lafayette, Indiana 3508 3512 3516 3520 3524 C175-12 C175-16 C175-20 3606 3608 3612 3616
Keil, Germany CM20 CM25 CM32 CM43 GCM34 M20 M25 M32 M43
All Gas engines Produced in Lafayette Indiana
Electric Power Modules Packaged @ FG Wilson or Griffen Georgia
32. Agenda
• Engine Families
• Engine Works & Wears
Engine Wear
Combustion Process
Internal Components
External Components
Cooling System
Lube System
Fuel System
Air System
Electronics
• Parts Differentiation
• REMAN
• Resources
33. Engine Wear
• Definition of Wear
Contact
Pressure
Relative Motion
• Normal & Abnormal wear
• Major wear items
Cylinder liners
Seals & gaskets
Piston rings
Turbo bearings and seals
Valves, guides, and seats
Main and rod bearings
34. Engine Works & Wears
• Engine Wear
• Combustion Process
• Internal Components
• External Components
• Cooling System
• Lubrication System
• Fuel System
• Air System
• Electronics
40. Engine Works & Wears
• Engine Wear
• Combustion Process
• Internal Components
• External Components
• Cooling System
• Lubrication System
• Fuel System
• Air System
• Electronics
46. Cylinder Head & Cam Shaft
C15
• A cylinder head is
installed on top of the
block
• The camshaft turns at ½
the speed of the
crankshaft to control
intake & exhaust
operation
48. Crankshaft
Rod Bearing Journals
Front Rear
Web
Main Bearing Journals
Counterweights
There are 2 rotations of the crankshaft for each 4 stroke cycle!
49. Cylinder Block
• The cylinder block is the
central component of
any engine
• It houses the
components that make
up the “Serious Nucleus”
of the engine
50. Engine Works & Wears
• Engine Wear
• Combustion Process
• Internal Components
• External Components
• Cooling System
• Lubrication System
• Fuel System
• Air System
• Electronics
51. Turbocharger
• An exhaust driven air compressor
• Impeller on the left
• Turbine on the right
• Connecting shaft, free floating
bearings, oil lubricated center housing
Causes of Premature Wear or Failure
• Poor oil quality
• Dirt ingestion
• Hot engine shut down
52. Waste Gate Turbocharger • The wastegate is opened by the
high pressure boost in the compressor
side of the turbo.
• Some of the exhaust gas then
Wastegate bypasses the turbine and escapes or
‘wastes’ to the exhaust stack.
Small turbo,
No wastegate
Boost
Small turbo,
with wastegate
Wastegate Actuator Large turbo
No wastegate
• Spins up quicker for good engine response
• Regulates turbo speed & prevents over-speeding Engine Load
53. • Heat exchanger for inlet air
Aftercooling
• Series of metal tubes through which hot
inlet air flows
• Heat from the air flowing from the tubes is
absorbed through the tube walls and carried
away
• 2 types
Air to air (ATAAC)
Jacket water (JWAC)
54. Causes of Premature Wearout &
Failure of Aftercoolers
• Most common cause -- failure of the
turbocharger compressor wheel
Damages aftercooler tubes
Coolant leakage into inlet air stream
• Poor coolant maintenance may cause
pitting/corrosion of the aftercooler tubes
Results in water to air leakage
Hydraulic lock on the engine
55. Water Pump
• Flow of the coolant begins at the
water pump
• Pump impeller creates the flow
• Water pumps are gear or belt
driven
• Water pump seals
Separates engine oil from coolant
56. Oil Cooler
Engine coolant flows from the
water pump directly into the oil
cooler
Oil carries heat away from critical
engine parts
Heat is transferred from the oil to
the engine coolant
57. Oil Cooler
Coolant flows through copper
tubes in the oil cooler housing
Oil flows around the outside of
the tubes
Scale build-up caused by
improper cooling system
maintenance can be cleaned out
of tubes
59. Engine Works & Wears
• Engine Wear
• Combustion Process
• Internal Components
• External Components
• Cooling System
• Lubrication System
• Fuel System
• Air System
• Electronics
60. Importance of Cooling System
40-60% Of All Engine Downtime Is Associated With
Cooling System Problems
Important Customer Reminders:
• Use proper start up procedures
• Clean debris from the radiator and fan
• Check radiator cap seal
• Inspect the water pump for leaks
• Select the right coolant
61. Function of Cooling System
• Maintain proper engine temperature
for optimum performance
• Dissipates excess heat from other
machine systems:
Engine
Transmission
Hydraulic
• Cools compressed inlet
air to optimize combustion
62. Cooling System Components
1 Water Pump
2 Oil Cooler
3 Passages through
block and head
4 Temp. Regulator &
Regulator Housing
5 Radiator
6 Pressure Cap
7 Hoses & Pipes
63. Causes of Cooling System Wear & Failure
• Single most common problem – poor coolant quality
Due to…
Not maintaining adequate levels of coolant additives
Using coolant that does not meet Cat’s specifications
Not keeping the cooling system topped off
Using coolant past its useful life
• Other problems include:
Coolant to air leaks in the aftercooler
• Causes hydraulic lock
Radiator or hose failures
• From reusing old radiators and hosing
• Failure to service the coolant relief valve
… most cooling system problems can be avoided
with proper maintenance practices!
64. Cooling Systems
Coolant flows around
cylinder liners
Absorbs heat from the
combustion chamber
Prevents breakdown of
oil film between pistons
and liners
65. Cooling Systems
Coolant flows through
passages in the cylinder block
into the cylinder head
Water seals between the head
and block prevent coolant
leaks
Some engines have water
ferrules to direct coolant to
critical areas
66. Engine Works & Wears
• Engine Wear
• Combustion Process
• Internal Components
• External Components
• Cooling System
• Lubrication System
• Fuel System
• Air System
• Electronics
71. Causes of Lube System Wear & Failure
• Single largest problem is short engine life due to
excessive soot in the oil
• Poor quality/low performance engine oil
• Extended oil change intervals
• Poor maintenance practices
• Fuel dilution
• Wear (Lube System Caused)
Seals/Bearings
• Turbo
• Crank - Main/Rod
• Valve, Guide
72. Methods to control soot levels in engine oil:
• High quality engine oils contain
effective soot dispersant additives
• High performance, full flow, lube filter
options
Standard, Advanced, & Ultra High
• Bypass filtration devices: centrifugal
or barrier filters
Soot particles
• Oil renewal systems (for large mining agglomerating together
machines)
Barrier Filter
Centrifugal Filter
Notes de l'éditeur
January 15, 2013
January 15, 2013
January 15, 2013 Let’s briefly review the agenda for the presentation. First, I will briefly go over the Caterpillar engine families, features of each family, their service strategies, and machine usage of the engines. Second, we will cover the works and wears of Caterpillar engines. Specifically, I will describe the works and wears of main parts of the engines starting with (1) internal components, then (2) the cooling system, then (3) the lubrication system, then (4) the fuel system, then (5) the air system, and finally (6) electronics on Caterpillar engines. Thirdly, I will briefly explain how Caterpillar engine parts are differentiated from competitive parts in design, quality, and life. Next, we will cover how Cat Reman Products supplies a viable repair option by offering quality remanufactured parts at a fraction of the price of new parts.
January 15, 2013 This chart shows that Caterpillar has a very broad range of power ratings (11 - 13,600 hp) for it’s diesel engine product line. Acquisitions of Perkins and MaK make this range the broadest in the world. Although shown on this chart, this presentation will not cover the Caterpillar 3600 Series Engine family or the C-M (Caterpillar-MaK) engine products.
January 15, 2013
January 15, 2013
January 15, 2013
January 15, 2013 An engine’s compression ratio is the ratio of the maximum volume of a cylinder (cylinder volume when piston is at bottom dead center) to the minimum volume (cylinder volume when piston is at top dead center). This ratio is usually expressed as a value-to-1. For example, if the maximum cylinder volume is 160 in. 3 and the minimum cylinder volume is 10 in. 3 , then according to the formula: 160/10 = 16 Therefore the compression ratio is 16:1 (16-to-1)
January 15, 2013
January 15, 2013 All engine manufacturers have to use a set of values given by the Society of Automotive Engineers to measure the horsepower of their engines. This is to guarantee that everyone is comparing the same set of values for their customers to compare with other manufacturers.
January 15, 2013
January 15, 2013
January 15, 2013 For 2002 and after, no dash between the letter and number means an ACERT engine
January 15, 2013 4 represents bore size like 4” bore size on the 3406
January 15, 2013 These are some of the features of the 3000 Series Engines. Dry Sleeve Engine One piece block assembly -- provides increased structural integrity and durability to the engine block, the core structure for the whole engine. Improved fuel economy Lightweight w/ high horsepower to weight ratios -- Since most of these smaller engines are used in vehicular applications, weight is important. When an engine’s power is used for vehicle movement, having a high horsepower to weight ratio is beneficial because not only is the engine moving the vehicle, but it’s also moving itself. So, if higher horsepower can be achieved with lower weight, power to move the vehicle is supplied more efficiently. How many work with these machines. How are you product supporting? Special Rates? They will be very popular We are working on product support. Some are supported at the component level, some at piece part. There are various fuel systems from suppliers.
January 15, 2013 We will now discuss the service strategy for the 3000 series engines, first reviewing the current serviceability for the engines, then going over the rebuild strategies for the engines. The current serviceability of 3000 series engines can differ depending on the engine model. For example, the 3003, 3013, 3024, and the 3034 are supported only at component level. This means that only whole components (like water pumps, oil pumps, turbochargers, etc.) can be purchased for these engines. Also, for these smaller 3000 series engines, reman offerings will be offered only as volume or the need dictates the creation of reman parts. On the other hand, the 3046, 3054, 3056, 3066 are supported at the piece part level. This means that individual piece parts for the components (such as seals, gaskets, o-rings, pump gears, etc.) can be purchased. Rebuild strategies for the 3000 series family also differ depending on the engine model. The 3003 - 3034 have and expected engine life equal to that of the machine life, and therefore will not be rebuilt. Conversely, the 3046 - 3066 have limited rebuild opportunities; the machine life is longer than that of the engine, so engine rebuild is one option to help extend the life of the machine. There are various fuel systems from suppliers.
January 15, 2013 C6.6The injectors are fully electronically controlled and located under the rocker cover. In the 3056E the injectors were fully mechanical and located outside the rocker cover. Quite a difference! 4 valves per cylinder The bottom end of the C6.6 ACERT is all new as well. With a sculpted block design, stiffness has increased and noise has decreased. In fact, the C6.6 ACERT is noticeably quieter than it’s predecessor. That’s the first thing most people notice about this engine… how quiet it is! A new heavy duty crankshaft handles the increased power output of the C6.6 ACERT, while new connecting rods and pistons do their part to increase power and lower emissions and noise. For the first time, 100% of the engine power can be taken off the front of the crankshaft . The C6.6 is currently used in industrial and generator set applications. Future machines that will use this engine include: WL 924,928,938; TTL 953,763; TTT D5N; WTS 613C; Wheel Skidder 525C
January 15, 2013 Crossflow cylinder heads help make air flow through the engine and combustion chamber more efficiently, adding to the overall effectiveness of ACERT. Cross-flow cylinder head design is an air system enhancement. It means that the air intake is on one one side of the head and the exhaust is on the other or opposite side. Intake air flows into one side and the spent exhaust gases flows out the other side of the head. The results are that the engine breathes better and will performs better and produces more power.
January 15, 2013 The ADEM A4 Electronic Control module manages fuel delivery, valve timing and airflow to get the most performance per gallon of fuel used. The control module also monitors engine and machine conditions while keeping the engine at peak efficiency. C& engine sound reduction features include composite valve covers with a fully isolated base, a steel oil pan and a cat iron front cover The turbocharged ATAAC system provides high horsepower with increased response time while keeping exhaust temperatures low for long hours of continuous operation. ATAAC keeps air intake temperatures down, maximizing fuel efficiency and minimizing emissions
January 15, 2013 Unlike 3000 series engines, all 3100 series engines basically have the same service strategy. In terms of current serviceability, all 3100 series engines are supported at the piece part level. Also, as one repair option, cost-effective rebuilds can be performed on each 3100 series engine. Another repair option for the 3100 series engines is reman. Reman components and piston packs are available for these engines along with limited availability of reman short blocks. Currently, a 3116 reman bare block is also available. Could press in dry sleeve into block for block repair.
January 15, 2013 Following are the features of 3300 and 3400 series engines: One piece block -- This engine block is a very rigid and durable cast block. One piece cylinder head -- is a one piece high strength gray iron casting that is designed for rigidity. The cylinder head is cast using an encapsulated core process, which improves core cleanliness and maintains closer casting tolerances resulting in a higher quality casting. Caterpillar fuel system -- Since a Caterpillar system is used, the engine components are designed to work as a system, therefore resulting in a systematic and predictable manner. Using will-fit parts is using parts that don’t incorporate “designed-in” qualities that may result in poor engine operation and failure. Replaceable wet cylinder liners -- are used so that worn liners can be replaced easily without having to bore the block (as done with parent bore engines). “wet” cylinder liners allow cooling of the liners to reduce friction and overheating which could cause early-hour failure. Roller cam followers and steel camshaft -- Roller cam followers help the push rods follow the camshaft geometry in a more controlled manner while reducing wear on the camshaft and on traditional cam followers. A steel camshaft provides increased strength and wear resistance which results in longer life and reliability. Totally hardened forged steel crankshaft -- Forging the crankshaft produces a high strength, rigid, durable crankshaft. Because it is totally hardened (through hardened), the crankshaft has a higher resistance to impact throughout the cross-section of the crankshaft. Together, forging and hardening contributes to a reliable crankshaft with a longer life.
January 15, 2013 Compression ratio 17:1
January 15, 2013
January 15, 2013 C15 ACERT is based off the C-15 platform Displacement changes from 14.6 to 15.2 ltr. Bore remains 137mm Stroke increases to 171mm from 165mm Compression ratio is constant across the various HP ratings. Major differences between ratings is seen in the turbocharger boost setting, fuel injector changes (e.g. nozzle orifice size) and camshaft configuration (fuel injector lobe). The increase to 18:1 compression ratio has beneficial effects on cold start and white smoke. One of the key features of ACERT technology is increased sophistication in the fuel injection system. A more powerful ECM is able to more precisely control the fuel injection event. C18 – Bore increased from137mm to 145mm Stroke increased from 171mm to 183mm
January 15, 2013 The C27 engine with ACERT™ Technology uses advanced engine technology to meet worldwide emissions regulations. The electronic engine delivers improved performance, serviceability, and reliability. The twelve cylinder engine is twin turbocharged and aftercooled with a high displacement to horsepower ratio. The large engine displacement produces better lugging capability, lower internal stresses, and longer component life. Two, single (one per head) overhead cams are driven by gears on the flywheel side of the engine (instead of a single camshaft in the engine block as found on the 3412E in the D10R). Placing cam gears at the flywheel significantly reduces noise and vibration. Vibration and noise add tremendous load to an engine and contribute to premature wear. The C27 features unprecedented tight system tolerances between the pistons and the wet cylinder liners. These tight tolerances support the significantly higher cylinder pressures and compression ratios in the engine, resulting in more complete combustion of fuel, reduced blow-by and fewer emissions. The C27 engine block eliminates internal bends and turns within the engine resulting in improved air flow. The block features a design that adds structural strength through compaction and thicker walls. The MEUI fuel system is a highly evolved fuel system with a proven track record of reliability in the field. It is a system that combines the technical advancement of electronic controls with the simplicity of direct mechanically controlled unit fuel injection. The ADEM™A4 electronic control module manages the fuel delivery and airflow to get the best performance per gallon/liter of fuel used. It provides flexible fuel mapping, allowing the engine to respond quickly to varying application needs. Increased compression ratio of 18:1.
January 15, 2013 3300 and 3400 series engine models are all serviced at the piece part level in addition to the sub-component level. Cost-effective rebuilds can be performed on all 3300 and 3400 series engine models. Also, Reman components, short blocks, long blocks, and complete engines are offered through Cat Reman.
January 15, 2013 Following are the features of 3500 series engines: One piece high strength cast engine block -- one piece block offers rigidity and durability, while casting the block offers high strength all resulting in a very reliable engine block with a very long life. Except for 3524 which has 2 blocks. Individual cylinder heads Four valves per cylinder -- to increase the flow in and out of the combustion chamber. Increased amounts of air allows more fuel to be burned and creates higher engine horsepower output. Self-aligning roller cam followers -- roller cam followers that follow the curvature of the camshaft lobes precisely so that valves open and close at precisely the right time to increase overall performance and efficiency of the engine. Oil cooled pistons -- oil reservoirs in the pistons allow cooling of the not only the piston skirt, but also the stainless steel upper part of the piston that is exposed to combustion. Keeping the pistons cool prevents out of round and fiction and other damage due to elevated temperatures of the piston. Unit injectors at 20,000 psi -- Increase injection pressures allows the fuel to burn more efficiently and effectively, providing increased horsepower and less emissions. NOTE: For elevated injection pressures in the injectors, fuel must be filtered very well or contamination particles will cause injection failure. Caterpillar fuel system -- Since a Caterpillar system is used, the engine components are designed to work as a system, therefore resulting in a systematic and predictable manner. Using will-fit parts is using parts that don’t incorporate “designed-in” qualities that may result in poor engine operation and failure.
January 15, 2013
January 15, 2013 This chart shows the engine usage in 4 selected vehicular applications; Track Type Tractors (TTT), Off-Highway Trucks (OHT), Hydraulic Excavators (HEX), Wheel Loaders (WL). The chart also shows how many other vehicular applications the engines are used in other than the 4 selected.
January 15, 2013
January 15, 2013 Hand in hand with the discussion of how engines work is how they wear. No matter the quality, every engine experiences wear, there is no denying it. (Yes even Caterpillar engines!) Wear is the result of three things; contact, pressure, and relative motion. All three must be present in a component or on a part in order for wear to take place. For our purpose, we will classify engine wear into two categories; normal and abnormal engine wear. Normal wear occurs in all engines. As parts push, slide and work against each other, wear occurs. Normal wear is that which we expect during engine operation. The normal wear items in a diesel engine include the piston rings, cylinder liners, valves and valve guides, main and rod bearings and if equipped, turbocharger bearings and seals. Abnormal wear is any wear other than that from normal engine operation. Generally, abnormal wear results from incorrect maintenance or operating technique. Using the wrong oil, extending oil changes interval, not maintaining the coolant conditioner concentration, and inadequate machine warm-up are typical practices that cause abnormal wear and premature engine failure. It is important to understand the major wear items in a diesel engine, and they’re worth repeating: Cylinder liners Piston rings Seals & gaskets Turbocharger bearings and seals Valves, guides, and seats Main and rod bearings Other parts which usually require reconditioning at overhaul but have a war life of two or more engine overhaul cycles are: Cylinder block Pistons Crankshaft Cylinder heads & valves Connecting rods Camshafts & valve train
January 15, 2013 We’ll start off talking about engine works and wears by first understanding some basic engine terms and the combustion process.
January 15, 2013 On the intake stroke, as the piston moves from top dead center to bottom dead center, air is pulled into the cylinder through the open intake valve(s). As the piston moves up, both the intake and exhaust valves are closed. Air trapped in the combustion chamber is compressed by the upward travel of the piston to around 1/15 th its original volume. As the air is compressed, the cylinder pressures increase up to 600 – 1000 psi Compressing the air to such a small volume causes it to reach a temperature of about 1,000 degrees F. This extreme temperature increase caused by the increase in pressure is called the “Heat of Compression”
January 15, 2013 On the power stroke, the piston reaches the top of its stroke, atomized diesel fuel is injected into the combustion chamber. The 1,000 degree F temperature of the compressed air causes the fuel to ignite immediately. The burning fuel raises the temperature in the combustion chamber to 3500 degrees F, producing rapidly expanding combustion gases, which increase pressure in the combustion chamber to over 1,800 psi. This high pressure combustion gas drives the piston downward. The downward force of the expanding combustion gas is transferred through the piston and connecting rod to the crankshaft, and converted to rotating power at the flywheel. By the time the piston reaches the bottom of its stroke, the combustion process has ended and no more power is transferred to the piston. The rotating momentum of the crankshaft and flywheel force the piston upward as the exhaust valve opens. Burned combustion gas is forced out of the combustion chamber and into the exhaust system. When the piston reached the top of its stroke, the exhaust valve closes, and the intake valve opens. The continuing momentum of the crankshaft and flywheel pulls the piston downward as pressurized air enters the combustion chamber through the open intake valve. This starts the intake cycle and repeats the combustion process.
January 15, 2013 This animation shows how the combustion process of a diesel engine creates reciprocating motion of the piston inside the cylinder.
January 15, 2013 This animation shows how the connecting rod and crankshaft convert the reciprocating motion of the piston inside the cylinder to rotational motion at the flywheel.
January 15, 2013 Most engine overhauls are due to normal long term wear of the piston rings. When the rings reach the end of their usable wear life, they begin to lose the ability to effectively seal combustion gas and control oil on the cylinder wall. Symptoms which indicate ring wear are: low power, excessive blow-by, and excessive oil consumption. Oil consumption occurs when lubricating oil on the cylinder liner walls is allowed past the piston rings into the combustion chamber or when oil passes into the combustion chamber due to excessive clearance between the valves and valve guides. Normally the rings control the amount and thickness of the oil on the liner wall, but if worn, the increased clearance between the ring and liner allows excessive amounts of oil in the combustion chamber. The oil then burns along with the fuel. As the engine operates, additional amounts of oil are consumed creating the need to continually add oil to the engine. Blowby occurs when combustion gases travel past the rings and/or valves and valve guides from the combustion chamber into the crankcase. This allows carbon, soot and other contaminants to mix with the oil increasing engine wear. Other causes of increased oil consumption and blowby include: worn turbocharger bearings and seals worn crankshaft seals worn oil-lubricated governor seals oil leaking into the fuel or cooling systems The terms oil consumption and blowby are often used interchangeably. To assist in diagnosing engine problems, blowby is a more specific term and is easier to measure than increased oil consumption. Blowby can be checked by measuring crankcase pressure with a pressure gauge or by checking blowby volume with a blowby meter. Oil consumption is harder to measure since it depends on good consistent maintenance records - something many customers don’t have. Also blowby can be measured at any time. Whereas oil consumption has to be measured over several days or weeks. The important point is oil consumption and blowby both result from engine wear, the most common type being piston ring and liner wear.
January 15, 2013 There have been many design improvements to the basic engine components and combustion development over the years. Improvements to the block, heads, pistons, rods, and bearings, and crankshaft have permitted much higher cylinder pressures to be converted to flywheel horsepower. We’ll start off talking about engine works and wears with internal components.
January 15, 2013 The internal components of an engine (here, the components that are required for the engine to supply usable horsepower) are: pistons, rings, and liners valves and valve guides connecting rods crankshaft, main bearings, and connecting rod bearings cylinder head gaskets The most critical wear parts (parts that need replacement most often) in the Internal Components category are: Rings Valve Guides Bearings
January 15, 2013 The C11/C13 engines have the cam lobe in the block itself as in this diagram; therefore, they use pushrods to operate the rocker arms whereas the C15 has its cam in the head as illustrated in a later slide. Intake and exhaust valves must withstand high heat and operating stresses of opening and closing. They are considered normal wear items and are replaced at each engine overhaul
January 15, 2013 The piston, piston rings, and cylinder liner work together to seal expanding combustion gas in the combustion chamber. Cyl. Liner: The cylinder liner forms the walls of the combustion chamber. It houses the piston and provides a path and dynamic sealing surface during piston movement. Part of engine block coolant passage that removes heat from the combustion chamber. The o-ring seals are used to contain the coolant circulating the coolant. Piston: The piston is the component which transfers the energy thru the connecting rod and into the crankshaft. The piston will act as a pump during, the intake, the compression and exhaust strokes, it’ll draw air into the cylinder, compress it and force exhaust out of the cylinder. Piston rings perform two critical functions: Provides a positive seal between the moving piston and stationary cylinder liner to prevent high pressure combustion gas from leaking past the piston. Scrape all but a very thin film of lube oil of the cylinder wall during the downward movement of the piston to prevent the oil from burning as the cylinder wall is exposed to hot combustion gas. There are 2 basic types of piston rings: Pistons usually contain 3 or 4 piston rings. All but the bottom ring are single piece compression rings. Top and middle rings are specially designed for their respective position on the piston. Their primary function is to provide a positive seal to prevent combustion gas from leaking past the piston. Oil control rings are typically a three piece design, with two narrow scraper rings and a spring expander to separate the scraper rings and force the against the cylinder wall. Oil control rings are always on the bottom of the piston so they can scrape excess oil off the cylinder wall during the downward stroke of the piston.
January 15, 2013 C15 uses a one piece steel piston. Connecting rod has four cap bolts and a oil hole through the beam to lubricate the wrist pin. Since a main part of ACERT technology is increased cylinder pressure, the piston and connecting rod have been beefed up to withstand the greater forces placed on them.
January 15, 2013 Connecting rods are one of the most robust parts of the engine. Rods rarely suffer physical failure unless they are subjected to extreme forces, such as an engine hydraulic lock or overspeed. Connecting rods may be reused for multiple life cycles, as long as they are not distorted, or do not display fretting at the rod cap from excessive use. Connecting Rod: Combustion forces are transmitted from the piston to the crankshaft by a connecting rod. It is connected to the piston with a pin at the top end It saddles the crankshaft connecting rod journal at the bottom end It is fastened in place with a connecting rod cap. Both top and bottom ends of the rod are free to rotate so that the up & down or reciprocating motion of the piston can be converted to rotary motion Combustion force loads are carried by the rod eye bushing & pin at the top. At the bottom end of the connecting rod, a bearing on the crankshaft pin journal supports combustion force loading.
January 15, 2013 The cylinder head is a structurally robust casting which has no inherent failure modes and typically lasts through multiple engine life cycles. Cracking of the cylinder head is a fairly rare occurrence, and is caused by severe engine overheating. Depending on the size and location of the crack, modern salvage methods often allow heads to be repaired. Pictured is a C15 cylinder head. Cylinder heads cover & seal to contain the combustion forces Also provides the air flow passages that route fresh air into and exhaust gas out of the combustion chamber. This entry and exit flow is controlled by the timed actuation of the valve train assembly controlled by the cam shaft. flow passages that route air/fuel/coolant/lubricant flow through and out of the head. AND KEEP THEM SEPRATE Cylinder Head: The cylinder head assembly is the cover that seals & contains the combustion forces. The head also provides the air flow passages that route fresh air into and exhaust gas out of the combustion chamber. This entry and exit flow is controlled by the timed actuation of the valve train assembly. The operation of the valve train assembly is controlled by the cam shaft. The intake & exhaust valves act as doors of the chamber. When the engine is running, the chamber & components are subjected to constant high temperature heat pulses generated by combustion. This heat must be removed to prevent damage to the engine. The cylinder head performs this function with flow passages that route coolant flow through and out of the head.
January 15, 2013 One piece unit on C11/C13 on highway truck engines and a option for C15. Works as an engine brake and controls inlet valve timing during the compression stroke. The CAT compression brake will be on some applications. This is a new component that has been developed and manufactured by CAT. Functionally it is similar to previous (Jake) compression brakes. The Cat compression braking system provides engine braking by opening the exhaust valves during the compression stroke of the engine. Using a conventional master/salve brake actuation system, the retarder opens the exhaust valves to release compressed air. The ECM contols the actuator valves through a data link that supplies and receives information from vehicle sub systems, automatically activating and deactivating the system as needed. Drivers can slow vehicle speeds on down grades without using the service brakes, making brake fade much less likely. The brake also helps the driver slow the vehicle without using the service brake when adjusting to ever changing traffic speeds on the highway.
January 15, 2013 The crankshaft is a very durable, forged and hardened component which lasts through multiple engine life cycles. The only wear parts on the crankshaft are the precision ground rod and main bearing journals. If moderate wear damage to the journal does occur, they can be re-ground within specified limits of material removal. Care should be taken during handling and assembly of the crankshaft to assure that no physical damage occurs to any part of the crankshaft, especially the machined surfaces. Physical damage could create a stress riser and increase the probability of a fracture and catastrophic failure. Crankshaft: Converts the up & down movement (reciprocating motion) of the pistons into a rotary motion to perform work. There are 2 rotations of the crankshaft for each 4-stroke cycle It is the power source of the engine and transmits energy to the flywheel and to the front gear train . The oil passages allow for oil to reach the journals to provide lubrication Describe & explain the parts of a crankshaft; front and rear, main brg journals, conn. rod journals, webs and counter weights. Crankshaft: The crankshaft converts the up and down movement (reciprocating motion) of the pistons into a rotary (horizontally spinning) motion that can be used to perform work. It is the power source of the engine. It transmits energy to the flywheel and the front gear train. The shape of the crankshaft determines the pistons timed movement though a stroke, the length of the stroke and the engines’ firing order. The crankshaft also smoothes out the operation of the engine by maintaining crankshaft inertia and greatly reducing the speed variation between timing pulses (power strokes).
January 15, 2013 The cyl. block is the structure that: The internal components mounted into The external components are bolted or fastened to. It is the cast iron foundation or supporting structure of the engine. The block when assembled has drilled and formed passages that allow coolant and lubrication oil to circulate through it.
January 15, 2013 We’ll start off talking about engine works and wears with internal components.
January 15, 2013 A key customer expectation is for increased power density; more horsepower from the smaller and lighter engines. This requires smaller engines burning more fuel to produce more horsepower. The turbo charger is basically an air pump that uses the energy of the escaping exhaust gases to compress and pump inlet air into the cylinders. Otherwise wasted exhaust energy is recovered and used to compress the inlet air. Exhaust gases flow from the cylinders, through the exhaust manifolds to the inlet, or turbine side of the turbocharger. The exhaust gases then travel from the turbine to the mufflers and exit the exhaust system. The energy from the moving exhaust gases passing through the turbine section of the turbocharger causes the blades of the turbine wheel to spin at very high speeds. The turbine wheel is mounted on a shaft that has a compressor wheel on the other end. The spinning turbine wheel drives the shaft, and causes the compressor wheel on the other end to turn at high speeds. The rapidly spinning compressor wheel draws clean air from the air filters and inlet piping, and pressurizes from atmospheric pressure to as much as 42 psi. The pressure of the compressed inlet air is known as “boost pressure”. The most common reason for turbocharger replacement is that it has reached the end of its expected wear life. If clean lube oil and inlet air is maintained, turbochargers usually run to engine overhaul. A common cause of premature failure of the turbocharger bearings is poor oil quality. These bearings spin at speeds up to 100,000 rpm and must withstand temperatures as high as 450 degrees F. Lube oil which is depleted or contaminated is not capable of providing adequate protection to the bearings. Dirt ingestion through the inlet air system causes erosion of the vanes on the compressor wheel. This erosion causes an out-of-balance condition which results in bearing failure. Turbos carry a tremendous heat load during normal operation. The bearings are protected by lube oil flowing through them, which provides lubrication and carries heat away. Shutting down a hot engine does not allow adequate time for the turbo to cool. When the engine is shut down, lube oil flow stops. The excessive heat in the turbo causes the oil in the bearings to cook into a hard carbon-like substance. This substance restricts oil flow through the bearings and results in bearing failures when the engine is restarted.
January 15, 2013 On a wastegate turbocharger, the wastegate is a governing system that kicks in at higher power levels. It vents excess exhaust gases to keep the turbine from spinning too fast. Wastegate turbochargers are a feature of ACERT Technology used in both on-highway and off-road applications. Using a smaller turbocharger with a wastegate the turbo spins up quicker giving good engine response. The wastegate regulates turbo speed and prevents overspeed.
January 15, 2013 The act of compressing the inlet air causes it to reach temperatures of up to 350 degrees F. This high temperature air is unsuitable for combustion. Peak combustion efficiency requires the cylinder be filled with the maximum amount of cool dense inlet air. Excess heat is removed from the compressed inlet air by passing it through a heat exchanger. The aftercooler is a heat exchanger that is simply comprised of a series of metal tubes through which the hot air flows. Heat from the inlet air flowing inside the tubes is absorbed through the tube walls and carried away. There are two types of aftercoolers. In an air-to-air aftercooler, air is pumped through the aftercooler housing and absorbs heat dissipated through the tube walls. This action transfers heat from the boost air within the tube to the cooler air in the housing. Jacket water aftercooler systems or separate circuit aftercooler systems use coolant pumped through the aftercooler housing to absorb heat. The heat is carried by the coolant to the radiator where it is dissipated through the radiator. The temperature of the compressed inlet air entering the aftercooler is about 335 degrees F. Upon leaving the aftercooler, the temperature has been reduced to about 190 degrees F which then travels through the intake manifolds on the engine and into the cylinders for combustion.
January 15, 2013 One of the most common causes of damage to the aftercooler is failure of the turbocharger compressor wheel. Catastrophic failure of the compressor wheel can cause physical damage to the aftercooler tubes resulting in coolant leakage into the inlet air stream on jacket water systems. Poor coolant maintenance may cause pitting and corrosion of the aftercooler tubes resulting in water to air leakage. Water leaking into the cylinders after the engine is shut down usually causes hydraulic lock and major engine damage.
January 15, 2013 Water pumps on Cat engines are generally gear driven, except on the 3208, 3114, and 3116 Engines which have belt driven water pumps.
January 15, 2013
January 15, 2013
January 15, 2013 Air compressor are mostly used for brake systems on trucks, but are sometimes used for air starting systems
January 15, 2013 The cooling system performs several function which are critical to proper machine operation: a) Maintains proper engine temperature for optimum performance b) Cools compressed inlet air to optimize combustion c) Dissipates excess heat from other machine systems and components such as engine lube oil, powertrain, turbochargers, brakes and steering and fan.
January 15, 2013 Why be concerned about radiators and cooling systems? 40 - 60% of all engine downtime is associated with cooling system problems. Cooling system components include the radiator, fan, coolant, water pump, oil coolers and water temperature regulators. It is important to remind our customers to use proper start-up procedures. For example, never start operating the machine until the engine has reached the correct temperature. Clean debris from the radiator and fan. Check the radiator cap seal to ensure the rubber seal is in good condition. Inspect the water pump daily for dripping coolant or oil. Select the right coolant Cat Extended Life Coolant helps prevent overheating, overcooling and other cooling system problems and at least twice as long as traditional coolant.
January 15, 2013 Diesel engines operate by converting the heat energy from diesel fuel into usable mechanical energy. Ideally, 100% of the heat produced could be converted into mechanical energy. In reality, a four stroke diesel engine is only about 33% efficient. Roughly 67% of the heat produced is dissipated by the following means: 30% cooling system 30% exhaust system 7% radiated by the engine The primary function of the cooling system is to maintain correct engine temperature by taking away unwanted heat generated by combustion and friction. The temperature of burning fuel in Caterpillar Engines can reach 3,500°F (1,927°C). Coolant circulates through passages in the engine called water or coolant jackets. The coolant absorbs heat from the hot engine surfaces and carries it to the radiator where it is dissipated into the atmosphere. The cooling system also helps maintain the correct temperature of engine oil, transmission oil, and hydraulic oil through the use of oil coolers. Finally, the cooling system also provides the means for the aftercooler to cool the compressed air leaving from the turbocharger upon intake.
January 15, 2013 Water Pump -- The water pump provides continuous circulation of coolant whenever the engine is turning. Water pumps on Cat engines are generally gear driven, except on the 3208, 3114, and 3116 Engines which have belt driven water pumps. Radiator -- The radiator transfers heat away from the coolant, lowering coolant temperature. Coolant flows through the radiator tubes while air circulates around the fins providing a transfer of heat to the atmosphere. Coolant is a mixture of water, antifreeze (glycol), and coolant conditioner (inhibitor). For proper cooling, each must be maintained in the correct proportion. Temperature Regulator -- Also called thermostat, the temperature regulator assists in engine warm-up and helps maintain coolant and engine temperature during operation. When the engine is cold the thermostat allows coolant circulation just through the engine, bypassing the radiator (to help the engine warm-up). When the engine is at proper operating temperature the thermostat opens to allow coolant flow through the radiator (so cooling takes place). The thermostat continually opens and closes as the coolant temperature changes. Water Temperature Gauge -- The temperature gauge indicates the temperature of the coolant. The recommended operating range is generally between 190°-210°F (88-99°C). Fan - The fan forces air through the radiator to transfer heat out of the coolant and decrease coolant temperature. Fans are usually belt driven off a crankshaft pulley, but sometimes are hydraulically driven. Oil Coolers -- Oil coolers function to maintain the correct temperature of engine, transmission, and hydraulic oils. The two basic types are oil-to-coolant and oil-to-air. 1. Coolant flow is initiated by the water pump that starts and continues pumping as soon as the engine is started. 2. Coolant circulates through the engine oil cooler to cool the engine oil. 3. From the oil cooler, coolant travels into the engine block and around the hot cylinder liners picking up heat and cooling engine parts. 4. Then it travels through intricate passages in the cylinder head(s) picking up more heat around the critical valve areas. 5. From the cylinder head(s) the coolant goes to the thermostat and on to the radiator for cooling unless the regulator forces the coolant to bypass the radiator at engine warm-up. Engines with turbochargers and aftercoolers circulate partial flow of coolant from the water pump directly to the aftercooler. Here the coolant is used to lower the temperature of the air coming from the compressor side of the turbo. In addition, some machines have torque converter and transmission oil coolers which are also cooled by engine coolant.
January 15, 2013 Problems in the cooling system can cause accelerated erosion or catastrophic damage to the core engine components. The single most common problem is poor coolant quality. Which causes accelerated cavitation erosion of cylinder liners, corrosion, and failure of waste pump seals. Poor coolant quality is due to: Not maintaining adequate levels of coolant additives Using coolant that does not meet Cat’s specifications Not keeping the cooling system topped off Using coolant past it’s useful life Other cooling system problems which can damage core engine components include: Coolant to air leaks in the aftercooler which can cause hydraulic lock Radiator or hose failures from reusing old radiators and hosing when a new engine is installed or failure to service the coolant relief valve. Hose failures can result in a sudden coolant loss causing a very rapid increase in temperature and cracked cylinder heads. With the exception of aftercooler leaks caused by excessive vibration, most cooling system problems can be avoided with proper maintenance practices. The most critical wear parts (parts that need replacement most often) in the Cooling System are: Water Pump Regulator Connecting Hoses & Pipes
January 15, 2013
January 15, 2013
January 15, 2013 We’ll start off talking about engine works and wears with internal components.
January 15, 2013 The lube system is the simplest, but most critical system of all to avoid damage to core engine components. Providing adequate lube pressure and keeping lube oil clean, cool and in good condition is essential to prevent accelerated wear or failure of piston rings and liners, main and rod bearings, and valve train components. The condition of the oil in the system is critical, 70-80% crankshaft bearing failures are due to oil contamination.
January 15, 2013 The engine Lubrication System has three main functions: Cleans Cools Seals & Lubricates Cleaning : Oil cleans parts by carrying away damaging metal particles that materialize during normal engine operations. Oil also cleans the cylinder walls and carries away carbon and lacquer deposits produced during combustion. Cooling : The second function of oil is to cool and seal parts by absorbing and carrying heat away. Sealing & Lubricating : Thirdly, oil forms a thin film or layer between the surfaces of moving parts to support and separate them. This prevents metal-to-metal contact that causes excessive wear. Synethic oil is not required for Cat engines. Customers can use it but we ship with petroleum based oil.
January 15, 2013 1. Oil travels from the oil pan (sump), at the bottom of the engine, up through the oil pump and 2. Then to the oil cooler. Here the oil is cooled by engine coolant. 3. Then the oil goes through the oil filter(s) where debris and contaminants are removed. 4. Clean oil then moves into the oil manifold where it takes two path: A. Into the engine to lubricate components, such as the bearings, gears, pistons, liners, valves, etc. B. And a smaller flow directly to the turbocharger. The oil then returns to the engine oil sump (pan) to start the cycle again. A bypass valve in the filter base allows unfiltered oil to bypass a plugged filter so the engine will always have some oil. When the oil is cold an oil cooler bypass valve bypasses oil around the oil cooler during start-up Components include: Oil Pump -- The oil pump operates whenever the engine is turning to provide continuous circulation of oil through the engine. Relief Valve -- If the flow of oil is restricted in the system, the relief valve will open at a certain pressure to discontinue flow of oil through the system so that pressure doesn’t build up and cause even more damage. Oil Cooler -- Coolant circulates through the oil cooler providing a heat transfer, from the oil to the coolant. This lowers the oil temperature and protects the oil properties. Oil Filter -- The oil filter cleans the oil by collecting metal particles and other debris that can damage engine parts. Oil Level Gauge (dipstick) -- The dipstick provides a method to check the amount of oil in the engine. Bypass Valves -- Bypass valves allow the flow of oil to be redirected to bypass or skip flow through a certain component. (1. Oil filter; 2. Oil cooler) Oil Pressure Gauge -- The oil pressure gauge indicates the pressure in the engine lubrications system during engine operation. Oil Pan -- The oil pan (sump) bolts to the bottom of the engine and is the reservoir for the engine oil.
January 15, 2013 Problems in the lube system can cause accelerate abrasive wear or catastrophic failure of core engine components. By far, the single largest problem is: Short engine life due to excessive soot in the oil. Microscopic soot particles accumulate in the oil very quickly due to more complete combustion on many newer emission controlled engines. Soot particles are highly abrasive and cause accelerated wear of piston rings, cylinder liners, and valvetrain components. At high altitudes soot levels may increase too fast to control by changing oil. Soot particles are too small to be effectively trapped with oil fiters or centrifuges. Poor quality/low performance engine oil. Inexpensive oils often have poor quality/low performance additive packages that cannot provide adequate performance or protection. Extended oil change intervals. Extending oil change intervals past the usable life of the oil results in increased soot levels, additive depletion and degraded lubricity and oil performance. Poor maintenance practices. Contamination of new oil due to poor handling or lack of filtration. Adding contamination to the lube system by pre-filling oil filters. Extending oil change intervals past the oils’ useful life. Fuel dilution – Contamination of oil due to fuel dilution reduces the oil viscosity and promotes premature wear. The maximum amount of fuel dilution allowed is 4%. By far, bearings and seals are the most sensitive engine parts to oil related problems, especially in the turbocharger. If a lubrication problem exists, the first sign will be worn turbocharger bearings and seals. Main and rod bearings and seals are the next most susceptible parts. But because they are bigger and thicker, they can often survive marginal lubrication longer than the smaller, thinner, faster moving turbocharger bearings and seals. The point to remember is; if bearing or seal wear is a problem, the cause will most likely be found in the lubrication system. Even though these seals and bearing are not “part of” the lubrication system, a problem in the lubrication system could cause wear here.
January 15, 2013 Modern engines with electronic fuel systems and controls burn fuel more completely and produce far less visible smoke from the exhaust stack. However, a byproduct of the improved combustion is a large increase in the number of very small soot particles in the combustion gases. Some of the combustion gases leak past the piston rings and into the engine crankcase. These soot particles and other combustion products are mixed with the oil in the sump and build up in the oil over time. Individual soot particles are smaller than a micron in diameter. Although many soot particles are only ½ micron in diameter, they are highly abrasive, and have a natural chemical attraction to bond together into larger abrasive particles. These large soot particles can cause accelerated wear and failure of core engine components. Modern oils have a very effective soot dispersant additive that overcomes the chemical attraction and keep soot particles suspended in the oil. But this presents a different problem; large numbers of small soot particles can still cause accelerated wear. Improvements in filtration have occurred that increase the filtration efficiency to better protect engine components from wear while still maintaining change intervals and without causes system restriction. A barrier filter is an additional filter added to the engine lube system that is much more efficient at removing small particles than the full flow filters. Two types: centrifugal and barrier. A barrier filter is a more efficient method of removing soot from oil since it is able to function better under different engine RPM cycles and on slopes and grades. A centrifuge filter must maintain peak speeds to remove soot. In large diesel engines, the most effective method of controlling soot levels in the crankcase is to consume it by mixing a controlled amount of oil with fuel and burning it. The consumed oil is then replaced with new oil. This is the oil renewal systems primarily used in the mining industry.
