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Engine assembly
NAME=DEV KUMAR MAHATO
U.ROLL. NO.= 7626147
COLLEGE ROLL NO.=1240775
Engine assembly
Before final cleaning
• Remove all sharp edges created by machining
• Clean all internal & external threads
Combustion chamberCrankshaft oil holes Top & bottom of cylindersOil pump gears
Chamfer top of bolt holesUse tap or die for restoring threads
Copyright 2003 Gary Lewis – Dave Capitolo
Engine assembly
Before final cleaning
• Check lifter bores for rust & burrs
• Check cam bores for burrs
Use glaze breaker if necessary
Could distort cam bearings if not deburred
Engine assembly
Final cleaning
• Only after all machining is done
• Use detergent hot tank
• Insufficient cleaning results in . . . Piston ring wearBearing wearValve stem wear
Engine assembly
Final cleaning
• Coat cylinders & decks with clean oil to prevent rust
• Coat valves, seats, & decks with clean oil
Engine assembly
Assembling cylinder heads
• Guides must be clean & lubricated
• Install valves with oil• Protect seals with plastic sleeve on valve
• Check cam rotation on OHC heads
Engine assembly
Installing core plugs
• Measure bore diameter to assure correct plugs
• Use deep plugs where possible• Coat outer edges for sealing
• Drive plug in slightly below block surface
Engine assembly
Sealing coolant, lubricants, & combustion
• Typical cooling system is 15 PSI @ 230°F
• Typical oil pressure range is 20-80 PSI
• Gasket must not restrict flow• Fire rings protect gasket material & cyl pressure
Engine assembly
Chemical sealers
• Sometimes used in place of gaskets
• Silicone sealers (RTV) are flexible & temp resistant
• Anaerobic sealers – Absence of air
Engine assembly
Head gaskets
• Metal-asbestos replaced with ceramic laminate
• Composite core copperGood compressibility, low compression, 60AA
• Composite core steelHeat resistant, high compression, 60AA
• Coated gasketsResin, polymer, better sealing of fluids
• MLS (Multi layer steel)For dissimilar metals, 15-20AA
Engine assembly
Head gaskets
• Stainless steel faceOn one side for high cylinder head temps,GM diesels
• Embossed steelImproved heat transfer, ridges provide crush for sealing, high compression, 30-50AA
• No-retorquePolymer coated, printed with silicone for low clamping force areas
Engine assembly
Gaskets
• Cork used on valve covers, lifter covers, oil pansStretches & shrinks
• Synthetic rubberCompressible, does not wick, resists heat
Engine assembly
Crankshaft seals
• Rope type seals must be fitted
• Lip type sealsLips face the oil
• Nitril & neoprene are common• Viton withstands loads & heat
Engine assembly
OHV assembly
• Only after sub-assemblies have been inspected
• Install core plugs • Install chamfered cam bearings
Engine assembly
OHV assembly
• Check cam for straightness• Check cam fit in bearings & scrape as needed
Cam must rotate freely• Blow all passages clear
Engine assembly
OHV assembly
• Grease cam to protect lobes & install cam
• Install oil galley plugs with sealer on outer edges
Engine assembly
OHV assembly
• Install rear main seal (two piece seal)
• Install main bearings• Install crankshaft & check clearance
Engine assembly
OHV assembly
• Oil all bearings & position thrust main cap
• Torque all main caps• Check crankshaft endplay
Engine assembly
OHV assembly
• Install thrust plate & timing set
• Check camshaft endplay
Engine assembly
OHV assembly
• Install piston assemblies
• Loctite & torque rod nuts
• Check rod side clearance
Engine assembly
OHV assembly
• Install oil pump & drive shaft• Verify cam timing at split overlap
• Install timing cover
Engine assembly
OHV assembly
• Install oil pan• Torque heads onto block
• Install rocker arms & pushrods• Adjust valves & test
Engine assembly
OHC assembly differences
• Balance shaft bearings• Crank & cam must be set to TDC before installation• Some timing covers are installed before head or pan• Timing belts and covers are installed last
Engine assembly
Sealing crankshafts
• Bearing clearance must not be excessive• Seal surfaces must be concentric with journals
Engine assembly
Sealing crankshafts
• Seals should be within .005” TIR of crank centerline
• Poor seal concentricity with main caps not centered
Engine assembly
Sealing crankshafts
• Seal surfaces must not have grooves
Engine assembly
Sealing crankshafts
• Rope type rear main seals• Coated with dry lubricant• Do not oil • Fitted with round stock, same size as seal surface
on crankshaft
Engine assembly
Sealing crankshafts• Lip seal rear main
Sealer on outer edgeOil on sealing surfaceThin coat of sealer at rear of parting line
Engine assembly
Sealing crankshafts• Side seals on rear main
Installed with nail or soaked in oil
Engine assembly
Valve timing• Check service manual for timing marks• Confirm by checking split overlap• Dual pattern cams don’t have equal lift & duration
Engine assembly
Valve timing• Valve timing can be adjusted with keys & bushings
Engine assembly
Pistons & rings• End gap .003” per inch of cylinder bore• Hypereutectic pistons use twice as much• End gap is increased by filing• End gap increases .003” for each .001” bore increase
Engine assembly
Pistons & rings• Oil control expander, then rails
Stagger end gaps• Lower compression ring, then top
Stagger end gapsOil grooves & check for rotation
Engine assembly
Piston types• Cast aluminum – OEM pistons• Forged aluminum – Stronger & better heat dissipation • Hypereutectic – High silicon content
LighterGood wear characteristicsTighter clearances due to low expansion rateRequires more ring end gap
Engine assembly
Piston skirts• Slipper skirts – Cam ground
Clearance for counterweightsSteel struts help piston expand with pin
• Barrel shaped skirt– Largest diameter is in the center
• Full skirt– Used in longer stroke engines
Engine assembly
Before attaching heads to blocks• Surfaces clean and flat
• Alignment dowels installed
• Threads clean • Sharp edges de-burred
• Check gasket direction Do not use sealer on coated gaskets
• Look up torque specs & sequence
Engine assembly
Attaching heads to blocks
• Torque in sequence in 3 steps• Threads lubricated with oil or sealer
• TTY bolts may need to be replaced
Engine assembly
Rocker arms
• Check rocker shafts for correct direction• Check for correct offset of rocker arms
Engine assembly
Valve adjustment
Piston at TDC, compression• Non-hydraulic valve trains
Adjust valves that are closed & rotate engine
• Adjustable hydraulic valve trainsZero lash plus pre-loadCollapse lifter and set clearance
• Non-adjustable hydraulic valve trains
Torque to specs
Engine assembly
Pre-oiling
Install lifters• Push rod engine
Rotate oil pump with speed handle
• Crank driven oil pumpsPre-lubricator used to pre-oil engines
• Assemble oil pump with grease for priming
• Crank engine with no spark plugs, fuel, or ignition
Engine assembly
Run-in stand
• Oil pressure & circulation• Compression• Noises• Gaskets & seals • Lifter rotation
THANK YOU