Remove all sharp edges created by machining Combustion chamber Engine assembly Before final cleaning Remove all sharp edges created by machining Combustion chamber Crankshaft oil holes Top & bottom of cylinders Oil pump gears Clean all internal & external threads Chamfer top of bolt holes Use tap or die for restoring threads Copyright 2003 Gary Lewis – Dave Capitolo

Engine assembly Before final cleaning Check lifter bores for rust & burrs Use glaze breaker if necessary Check cam bores for burrs 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 wear Bearing wear Valve 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 copper Good compressibility, low compression, 60AA Composite core steel Heat resistant, high compression, 60AA Coated gaskets Resin, polymer, better sealing of fluids MLS (Multi layer steel) For dissimilar metals, 15-20AA

Engine assembly Head gaskets Stainless steel face On one side for high cylinder head temps, GM diesels Embossed steel Improved heat transfer, ridges provide crush for sealing, high compression, 30-50AA No-retorque Polymer coated, printed with silicone for low clamping force areas

Engine assembly Gaskets Cork used on valve covers, lifter covers, oil pans Stretches & shrinks Synthetic rubber Compressible, does not wick, resists heat

Engine assembly Crankshaft seals Rope type seals must be fitted Lip type seals Lips 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 edge Oil on sealing surface Thin 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 gaps Oil grooves & check for rotation

Engine assembly Piston types Cast aluminum – OEM pistons Forged aluminum – Stronger & better heat dissipation Hypereutectic – High silicon content Lighter Good wear characteristics Tighter clearances due to low expansion rate Requires more ring end gap

Engine assembly Piston skirts Slipper skirts – Cam ground Clearance for counterweights Steel struts help piston expand with pin Full skirt– Used in longer stroke engines Barrel shaped skirt– Largest diameter is in the center

Engine assembly Before attaching heads to blocks Surfaces clean and flat Threads clean Sharp edges de-burred Alignment dowels installed Check gasket direction Do not use sealer on coated gaskets Look up torque specs & sequence

Engine assembly Attaching heads to blocks Threads lubricated with oil or sealer Torque in sequence in 3 steps TTY bolts may need to be replaced

Engine assembly Rocker arms Check for correct offset of rocker arms Check rocker shafts for correct direction

Engine assembly Valve adjustment Non-hydraulic valve trains Piston at TDC, compression Adjust valves that are closed & rotate engine Adjustable hydraulic valve trains Zero lash plus pre-load Collapse lifter and set clearance Non-adjustable hydraulic valve trains Torque to specs

Engine assembly Pre-oiling Push rod engine Install lifters Rotate oil pump with speed handle Crank driven oil pumps Pre-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