Chapter 10
Nanoslide Technology
A Plasma Spray welding technique developed by Mercedes-Benz to coat cylinder walls with a tool-grade hardness iron alloy.
Cross-bolted Blocks
A Variation of the deep-Skirt block that uses additional horizontally placed bolts to connect the crankcase walls of the block to the main bearing caps; also known as a tie-bolted or bolster-bolted block.
Warp Anchor
A block design that has the cylinder head and cylinder block bolted together by tie bolts; sliding steel sleeves, which are locked into the block, accept the cylinder head bolt from one side and the tie bolt from the other.
Ladder-Frame Blocks
A block design with sides that extend exactly to the centerline of the crankshaft bearings and a separate, additional section that attaches to crankcase and the oil Pan and incorporates the main bearing caps into one unit.
Wet Sleeve Block
A block designed with a number of large holes into which the cylinder sleeves are inserted; coolant has direct contact with the outside of the sleeve and there is no supporting cylinder bore structure.
Compacted Graphite Iron (CGI)
A material produced from powdered iron alloys squeezed into molds at high pressures and then treated to bond the metal particles together; also known as Sintered Graphite.
Dual Mass Flywheel
A number of medium-duty engines incorporate specialized torsional vibration dampening springs in the flywheel construction. When connected to a manual transmission, DMFs enable the use of lighter transmissions and drivelines by minimizing torque spikes produced by torsional vibration. Transmissions shift easier and transmission gear rattle is virtually eliminated with DMFs
120 degree of spacing
A six cylinder engine will have how much spacing between each Rod Journal. (720 degrees over six Cylinders)
Harmonic Vibration
A vibration that sends pressure Waves moving back and forth along the crankshaft.
Aluminum cylinder blocks use
A warp anchor Principle
Season
After rough casting blocks tend to warp. to prevent this, diesel blocks are often stored at high temperatures for a day or two to heat treat.
Spray welding
Also called Plasma welding, applies an alloyed iron coating over the cylinder wall.
Parent-Bore Block
Also commonly called a no-sleeve block, has holes cast and bored into block, and the pistons are inserted directly into these holes.
77lbs
Aluminum can eliminate more than how much weight compared to similar engine blocks made from cast iron.
The Upper Shell of A Main Bearing
Always has a hole to receive lubrication and a circumferential groove to channel oil from the oil supply hole to the bearing. Rod bearings are used on the crankpin journals or connecting rod journal surfaces.
Cylinder pressure
Applied against the piston and connecting rod can assembly is intense enough to also deflect and twist the crankshaft while it rotates.
Paired cylinders
Are 1 and 6, 2 and 5, 3 and 4.
Cylinder Walls and bearing bores
Are fabricated from casting iron liners into the aluminum block structure to provide durable, low-friction wear surfaces.
Main Bearing Caps Are help
Are held in place with two or four vertically placed bolts.
Flywheels
Are like large plates bolted the rear of the engine And they serve several purposes. their primary purpose is to provide some inertia between power impulses to keep the engine rotating. Storing energy in the heavy flywheel produced during each power impulses helps smooth out engine speed.
Tunnel-Bore blocks
Are one of the smoothest operating and strongest block designs. Intergrating the main bearing bores into a single solid block structure makes this block the strongest and most rigid.
Balance Shafts
Are used dampen secondary engine vibrations made by piston movement. When Two Balance shafts are used they rotate in opposition to one another at twice the engine speed, countering secondary imbalance forces. Balance shafts help eliminate vibrations that drivers feel transmitted through the engine movement to the Steering wheel, seats, floor pan, or instrument panel.
Secondary Balance
Balanced achieved when the movement of one piston counterbalances the movement of another, result in smoother running engines.
Disadvantage of Dry sleeves
Because the coolant is not in direct contact with the dry sleeve, heat transfer from the combustion chamber to the coolant water is not as rapid as it would be with a Wet-Sleeve. This slow heat transfer may potentially result in limitations on power output per cylinder, engine life. and cylinder damage.
Camshaft and Crankshaft Speed Variation
Between 3% and 6% during each crank rotation, which affect gear train durability and noise emissions.
Cylinder Block
Can be described as the largest single part and backbone of the diesel engine.
The weight of an engine block made from (CGI)
Can be reduced by 22% through a 15% reduction in the thickness of the block walls.
Higher Vibrational Energy
Can lead to over heating and shorten an elastomer dampers life.
Severe torsional Vibration
Can result in damaged or broken crankshafts, camshafts ,and severe wear of gear trains mechanisms. taming torsional vibration is nessacry to avoid not only engine damage but also unpleasant driveline noise, vibration, and harshness (NVH) in a Vehicle.
Disadvantage of cast iron
Cast iron does not transfer heat as readily as aluminum. Cast iron cannot be as easily repaired as steel or other metals.
high cylinder pressure combined with a rapid combustion phase
Create usual vibration and torsional twisting forces in diesel blocks.
Removing a Dampener
Dampeners should never be removed with a puller applied to the outer ring. Most dampeners are designed to be removed with hand force only. Pulling on the outer ring or the case of a Viscous Dampener destroys the component because distortion of the case or twisting the inertia ring will prevent proper mechanical functioning of the damper.
Deep-Skirt Block
Design refers to a block configurations in which the bottom edge of the block extends well below the Camshaft outline. The sides of the crankcase are separated from the Main bearing caps to minimize transmission of noise produced by vibrations from the main bearing caps.
Cavitation erosion
Diesel engines have a unique problem known as.
Main block structure
Encloses the cylinder components
Lengthening The Block Walls
Enhances structural rigidity and operating smoothness, and allows for a larger mating surface with the transmission. A reinforcing bedplate may also be attached to the oil pan rails and main bearing caps to enhance the rigidity and strength of the blocks crankcase.
Elastomer Dampers, Viscous or fluid dampers, combination dampers, Rotating pendulum vibration absorber, Balance Shafts.
Five types of dampener construction are used on diesel engines.
Cavitation
Greater Attention to maintenance of the cooling system is required in wet sleeve engines to prevent. Cavitation can cause pinholes to perforate the sleeve, allowing coolant to enter the cylinder or combustion gases to enter and pressurize the cooling system.
Heating the Block
Hardens them, making them resistant to stress and minimizing future distortion.
Detroit S60 Series Engines
Have Weep holes to drain coolant that may leak past the damaged liner O-Rings to the outside of the block. This prevents coolant from entering the oil pan.
Magnetic induction
Heat is produced in the metal, which is then quenched with water to produce a hard, wear- resistance metal surface
0.03
Induction hardening is no more effective than.
The cylinders can be arranged
Inline, V Banked, or horizontally opposed.
1-2-7-3-4-5-6-8
International V8 firing order
Primary Balance
Is Achieved when the crankshaft counterweights offset the weight of the piston and connecting rod assembly.
Induction Hardening
Is a heat treatment process that involves passing alternating electrical current through coils of heavy-gauge wire surrounding the material to be hardened
Scissor gear
Is actually two separate gears incorporated into a single unit.
Inline six Cylinder Engine
Is among the best balanced configurations for the internal combustion engine, possessing excellent primary and secondary balance characteristics.
Aluminum
Is being used more commonly as a bock material in high-performance diesel engines, while improving performance, it also saves on weight.
Inline Block
Is better to Handle higher cylinder pressure with greater durability than V-Block configurations.
Dry Sleeve-Block
Is designed with a bored or honed hole in the block that allows no coolant contact with the cylinder sleeve. The sleeve is inserted into the bored hole as either a slip or press fit.
The Engine Block
Is the Main structure of the engine and encloses the cylinders and crankshaft. The block has two main sections: The Cylinder Block which contains the Cylinders, and the Crankcase which contains the crankshaft.
Cylinder Block Primary function
Is to support liners (if equipped) as well as major engine componets such as the crankshaft and camshaft.
Moving the Gear train to the rear of the engine
Is where torsional vibrations are reduced due to the heavier flywheel mass can dramatically reduce Gear train Noise . Gear life and valve timing accuracy are also improved.
Cross Bolting
Limits Crankshaft flexing, stiffens the engine structure, and reduces overall vibration. This type of block reinforcement technique permits further weight reductions.
The Gear Train
May be located in Front or Rear of the engine.
Direction of Movement for a V-block
Movement may be 60, 72, or 90 apart.
0.012
Nitriding, this hard finish does not extend more than (0.305 mm) deep, but is one of the hardest journal surface finishing techniques.
Compacted Graphite Iron Can also improve
Noise transmission through the block by dramatically reduced as well because the Vermicular (wormlike) grain structure of CGI has sound sound-absorbing properties.
Cavitation Erosion
Pinholes produced in cylinder block walls heads and liner sleeves result of the collapse of tiny water vapor bubbles formed when coolant vaporizes on hot cylinder wall surfaces. Pressure exerted by the force of the bubble collapse is reported to be as high as 60,000 PSI (413,685 KPA).
Many cylinder blocks are also produced in
Single, Two, and three
Cast Iron is not as strong as steel?
So machine threads usually have a coarse thread pitch to minimize the problem of stripping threads
Core Plugs
Sometimes called frost plugs because they are pushed out by frozen coolant, are used to cover holes made in the block to flush sand out of small passageways during casting.
40% more rigid and 100% more fatigue resistant
The Ford 6.7 (409 Cubic Inch) Powerstroke uses a patented SinterCast CGI material That helps with
The Ladder-frame block Incorporates
The Main bearing caps into a single structural component resembling the rungs of the ladder. the frame supports the crankshaft and adds structural rigidity and strength to the block, reducing noise and vibration.
Major Disadvantage Of a Parent-Bore Block
The Major Disadvantage is that during rebuild or repair of the engine, a worn cylinder must be rebored or honed.
Reinstalling a Flywheel
The housing centerline often does not match the centerline of the crankshaft, even if alignment dowels are used. If the center lines are not correctly aligned, a number of significant problems can occur First the rear main seal may leak. Also on a manual Transmission the input shaft bearing and seal will quickly fail because the input shaft is operating at an angle.
In a Viscous Dampener.
The inertia ring rotates inside a sealed case connected to the crankshaft. A thin film of highly viscous silicone fluid fills the small gaps between the inner inertia ring and the outer case.
Sputter Bearings
The latest technology in bearing overlay material, Which deposits a metal overlay surface onto a bearing backing that is three times harder than convention overlay. This complex process involves spray welding in a vacuum and is used to make a bearing that has the highest ability to carry a load over any other bearing.
Advantage Of a Parent-Bore Block
The most notable advantage is that it cost less to construct, because matching and fitting of cylinder sleeves is not required.
50%
The result is a low-friction surface that reduces mechanical losses due to friction of up to, in comparison to cast- iron cylinder liners.
Torsional Vibration
The speeding up and slowing down of the crankshaft caused by alternating compression and power strokes of the engine cylinder.
0.004-0.006
The technique first melts wire of iron-carbon in an electric Arc pressurized gas deposits the material onto the cylinder walls to only.
Induction Harding and Nitriding
The two most common processes used to harden bearing surfaces of the crankshaft.
Combination Dampeners
These Dampeners combine the advantages of both Viscous and Elastomeric Dampeners. Elastomeric dampeners provide good low speed harmonic dampening in comparison to viscous dampeners. However, at higher speeds the Reverse is true, and Viscous Dampeners provide better harmonic vibration dampening.
What do Main bearing caps have and use to improve block strength?
They are Hardened or use special alloys.
V-Block Advantage
They are a more compact design, which permits lower hood profiles.
Weep Holes
To drain the leaked coolant and prevent it from entering the oil pan.
Nickel, Molybdenum, and Chromium alloys
To improve strength, hardness, and Corrosion resistance, Manufacturers added these materials.
What causes Torsional Vibration
Twisting action produced by power impulses in the engine and resistance to crankshaft movement by the driveline and compression strokes.
Pendulum Vibration Absorbers
Unlike regular balancers, they provide torsional control by producing forces that directly cancel the forces that produce torsional vibrations
Alternators, A/C compressors, And other accessories
Will loosen and fall off due to excessive torsional twisting of the crankshaft.
Compacted graphite iron (CGI) Construction Technique
Yields blocks with at least 80% higher tensile strength, 45% greater Stiffness and approximately double the fatigue strength of conventional cast iron and aluminum.
Tensioned Set of Springs
Zero lash between the gears teeth is maintained.
Specific RPM
accessory drive belts can be spontaneously thrown and driveline vibration can occur due to torsional vibration.
four to seven times the rate of iron
aluminum has an expansion rate coefficient.
Firing Impulses
applied to the crankshaft cause variations to its rotational velocity.
Reduce Torsional Twisting
at the opposite end of the crank, a vibration damper is located at the front of the crank where it is needed to reduce both torsional and harmonic vibrations.
Cast Iron Cylinder blocks, or other iron components such as cylinder heads.
cannot be easily repaired by welding. broken or cracked parts most often require replacement. some block porosity problems causing oil leaks can be repaired with special epoxies.
60%, 72% , OR 90%
cylinder Bank leaned result in an engine with less overall height.
The Number of cylinders in a block can be configured in
four, five , six, eight, and even ten and twelve cylinder bores.
What can cause Intense Torsional Vibration
high compression ratios and even higher cylinder pressures of a diesel engine can produce what?
Cylinder Component assemblies
include pistons, rings , wrist pins, and connecting rods.
Gear Train Rattle
is an issue in diesel engines, affecting not only noise but also durability.
Using Scissor Gears
minimize gear rattle, a common problem in the long gear trains of overhead camshaft engines.
Cast Iron
refers to metal made from iron ore with carbon content of 3-5%
Crankcase
the area below the cylinder enclosing the crankshaft and its bearings.
The dynamic forces of piston weight can be canceled out
the forces of pistons moving in the opposite directions.
How is Torsional Vibration observed
watching the Back-and forth oscillation of belt tensioners. the change of speed of the crankshaft causes drive belts to alternately stretch and shorten, thus causing tensioner movement and belt vibration
Coolant has Direct Contact
with the outside of the sleeve and there is no supporting cylinder bore structure like a dry sleeve around the wet sleeve. O-Rings prevent coolant from leaking out of the water jackets and into the oil pan.
