Steps
Engine Block Inspection
- Perform a visual inspection of engine. Inspect fluid sweeping out of core plugs. Inspect the water pump for leakage. Inspect the Harmonic Balancer for cracked rubber. Check for any signs of overheating. Check for any excessive gasket sealer left behind from previous work.
- Check the ID and casting numbers. This is to ensure that the engine you think you are working on is actually the engine you are working on. Engine swaps are semi-common now a days and each engine has different specifications.
- Inspect the external components on the engine. Inspect the distributor for wobble & looseness. Inspect the alternator belt, spin the pulley and listen for any unusual noise. Inspect the clutch assembly for wear.
- Remove the oil pan. If the engine is in the vehicle the frame cross-members and the frame and the transmission my obstruct removing the oil pan. Often the engine needs to be out of the vehicle.
- Remove valve heads. If the manifolds and the many vacuum hoses and wiring have not been removed yet, first make drawings and take photos and label hoses and wires with tape with permanent ink. Do not depend on memory. Some wires and hoses will only plug into place in one way, but some are not obvious; so you still need a chart, diagram/drawing and pictures to ease reassembly.
- Remove the ridge on the cylinders near the top of the bore with a cylinder reamer (rimmer). The ridge is defined as the point where metal of the cylinder did not wear because the rings do not rise that high in the bore. The cylinder wear is below this point, but the ridge must be reamed out before removal to allow pistons to be removed and without damage and to make re-installation of the pistons with new rings possible.
- Remove piston and rod assemblies. After removing the rod caps from the rods, place rod journal protectors (protective covers) on the rod ends and protect bolts to prevent them from striking, scraping and scoring the engine block or from bolt threads being damaged during removal and handling. Once removed replace the same rod cap back on the matching rod, keep them as numbered paired/matched sets. Keep the parts marked or in order for return to the same cylinder from which they were removed. This to assure balance and fit; and consistent "break" in.
- Remove and inspect the crankshaft. Once removed store in a safe place, preferably use crank mounting plates so that you can accurately measure the crankshaft. Keep old main bearings in order, inspect them for wear and excess dirt. With the crank removed and stored correctly place the main caps back on the engine block and torque to specification.
Crankshaft Inspection
- Perform a visual inspection of the crankshaft. Inspect for cracks and any signs of overheating.
- Measure different crankshaft dimensions. These dimensions include journal diameter, out of round, taper, and run out. If the crank is out of spec mark it for identification and have it sent to the machine shop. Once the machine shop has reground the crank use a rifle brush to remove the excess debris from the oil passages. Then measure the crankshaft again so that you can replace the bearings to get the crank to bearing clearance within specification.
- Replace the pilot bearing
Engine Block Inspection 2
- Remove the camshaft, balancer shafts, and auxiliary drives. Pay attention to end play shims and spacers, keep these organized you will need to put these back in the correct order. Remove bearings, pay attention to their position.
- Remove the core plugs, brackets, guide pins, and everything else still attached to the outside of the engine block.
- Perform a visual inspection of the engine block for any cracks.
- Magnaflux the engine block. Magnaflux should only be used to find leaks on cast iron and steel only. Use dye penetrant to find cracks on aluminum blocks.
- Using a straight edge and a set of feeler gauges check the deck surface for flatness. Measure the both diagonally and horizontally. If the deck surface exceeds the specification for flatness resurface the block. Use caution when resurfacing not to remove too much material. If too much material is removed you risk having the pistons collide with valves.
- Using a dial bore gauge measure each cylinder bore’s taper and for out of round.
- Inspect each cylinder for discoloration and washboard. Use a rigid stone hone to identify washboard.
- Check alignment and out of round of the main bearing bores with a dial bore gauge.
Valve Head Disassembly
- Use a valve spring compressor to compress the valve spring.
- With the valve spring still compressed remove the valve keepers.
- Slowly release the valve spring out of compression. Once you can remove the compression tool, remove the valve springs and shims. Keep these components in order.
- Remove the valve from the head, do not force it out as it may score the guides. Repeat these steps until all valves have been removed from the valve head.
- Remove any carbon buildup or dirt from valves and valve head. If possible have the head shot peened or glass beaded.
Valve Head Inspection
- Use magnaflux or dye penetrant to find any cracks.
- Check the valve head for flatness. Note any flatness which is out of specification so that it can be corrected after inspection.
- Inspect the guides for excess wear using a dial indicator.
- Check for recession of the valve seats
- Check for worn valve stems is a micrometer. Replace any valves whose stems exceed specification
- Check for worn keeper grooves. Replace any worn keepers.
- Check the thin margins on the valves. Margins are thinner on intake valves than exhaust valves. Replace valves with excessively thin margins.
- Measure the valve springs free length, tension, and squareness. Replace any springs which are worn beyond specification.
Valve Head Reconditioning
- Recondition the worn valve guides
- Replace the recessed valve seats
- Reface all valves which are not going to be replaced.
- Machine the valve seats.
- Lubricate the valve stems with engine oil.
- Install valve seals. The valve seals come in 3 different types: band, umbrella, or PC type. Pay attention to the order of assembly.
- Assemble valve heads.
- Check for leaks using either a liquid test or a vacuum test.
Block reassembly
- Clean block using soapy water, then air dry.
- If the block was machined, recheck all the dimensions. Machine shops do make mistakes, its your job to double check their work. Check that the oil channels and openings of the oiling system of the block are free and clear of all metal shavings, dirt and debris.
- Wash block again using hot soapy water, then blow dry.
- Blow out all bolt holes using compressed air to remove any debris prior to installing fasteners.
- Install oil gallery plugs and core plugs using hardening sealer. Never use silicone sealer in these areas (it can dissolve and also could form into rubbery debris in the oiling system).
- Grease the camshaft bearings with high pressure grease, then install camshaft.
- Prepare to lubricate main bearings by cleaning and drying the main bearings bores and backs of bearings. Lubricate the inside of all the main bearings and the lip on rear main seal with the recommended OEM oil/grease. Then install main bearings and rear main seal, be sure install in the correct position, they are position sensitive.
- Install crankshaft and main caps. The caps are sensitive to position and direction. Snug the caps and then begin to torque the caps onto the block from center out in 3 stages.
- Rotate crank to ensure it is not binding. If the crank rotates smoothly, then next check end play.
- Install the timing chain to specification being sure to align the timing marks correctly.
- Degree the cam. Aligning timing marks sets the cam degrees correctly with the crankshaft/piston timing and proper valve timing sequences for intake, compression, power, and exhaust strokes of the engine.
- Check piston ring end gaps for OEM clearances. You may need oversize rings: they come in various oversizes. If rings were too small in diameter they would have excessive end gap, but if they were too large then they would be too tight and can bind and could break when the engine heats up--when the engine is running.
- Stagger ring end gaps on pistons (This means that the tiny gap at the ends of each ring are turned 180 degrees apart around the piston, compared to the next ring so this will reduce blowby. Be sure oil expander ring is fitted/butted properly.
- Using rod journal protectors, install the piston and rod assemblies. Lubricate rod inserts, install and torque rod caps and while you are installing the rods, first barely snug and then torque these gradually in 3 stages to ensure that they all seat evenly and properly.
- Rotate crankshaft after installing each piston and torquing the rod caps to make sure it still rotates freely so that:
- Install head gasket (the gasket may be directional, be sure to install in the correct direction. Do no forget to put in the head to block bolt FERRULES or the OHC belt will never run true and then shread.
Never use gasket cement unless the gasket maker say so.
- Install the valve heads. Lube the bolt threads and washers with OEM lubricant or sealer, then torque the bolts down in 3 stages using OEM specified pattern: Pay attention to length and location of bolts.
- Install valve train, be sure to lubricate the parts as you install them.
- Adjust valves as necessary (minimum up/down movement, then torque 3/4 turn)
- Install the rest of pans, covers, pulleys, ect...
- Paint as required
- Double-check everything
Warnings
Things You'll Need
- Dial bore gauge
- Rifle brush
- Magnaflux
- Dye penetrant
- Straight edge
- Feeler gauge
- Dial bore gauge
- Rigid stone hone
- Round straight edge
- Valve spring compression tool
- Solvent
- Dial indicator
- Micrometer
- Spring compressor
- 90 degree straight edge
- Stones or cutters
- Engine oil
- Scrub brush
- Hardening sealer
- Pry bar
- Piston ring compressor
- Rod protectors
