Editing How to rebuild an engine (section)
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==Disassembly== Disassembly is usually broken down into two parts. One is removal of external parts and accessories and the other is the actual disassembling of the engine block and its internal parts. ===External parts and accessories=== The first items that come off of an engine that will be rebuilt are the exhaust manifolds. Then, take off all the brackets holding the A/C compressor, alternator, power steering pump, and smog pump. Then take the distributor out. Wrap a clean rag around the bottom end of the distributor, and then put it into a zip-lock plastic bag. This can be cleaned later. Now for the carburetor or fuel injection or throttle body. Put the injectors into plastic bags. Again, when it comes time to put new O-rings on the injectors you can work on each, one at a time, without getting them dinged up by being knocked around in one of the fastener cans you will be using to hold nuts and bolts. If the engine has a carburetor, do not turn it upside down unless you plan on installing a rebuild kit on it also. Any "crud" that has settled to the bottom of the carburetor fuel bowl will become lodged in places you do not want dirt or rust, so keep it right-side up and again wrap a clean rag around it and then pop it into a plastic bag. Store the carb, distributor and any other fragile parts carefully to avoid damage. If you are working on an engine with a throttle body just put the unit in a plastic bag for now. At a later time you can put in new O-rings. You just don't need all these parts in your way until you start to reassemble the engine. For an engine with a carburetor now is the time for the fuel pump to be taken off. On the Small Block Chevy (SBC), there is a mounting plate that needs to be removed that has a fuel pump push rod behind it that needs to be removed as well. You can put this rod and the spacer plate in with the fasteners. ===Engine block and internal part disassembly=== Disassembly of the engine starts with the removal of the valve covers. The rocker arms should then be removed and placed in number sequence so that they can easily be identified from where they came. Pushrods can be pulled and placed in a shallow pan for cleaning and possible reuse. Head bolts should be removed and inserted in a cardboard template to make note of their location. Prying up with a pry bar in the intake ports to cause separation of the head from the block, watch for coolant spills. Use a wide blade screwdriver to leverage the heads up off the block and dowel pins. Remove the heads to a solid work bench for inspection. Before the cam can be removed, the damper and timing cover have to be removed. Use a puller to remove the damper and remove the oil pan before removing the timing cover to avoid bending it, if this is a SBC engine. The SBC engines from the factory sometimes had a nylon covered cam gear. This nylon can- and did- come off when the gear wore out. The plastic pieces then fell into the oil pan to be sucked up in the oil pump screen. This has caused many failures in the past. If you see a gear missing the plastic on ANY engine, you know the pan and pump need to be inspected and cleaned of any plastic. Remove lifters from their bores; use a hook or removal tool and carb cleaner spray to remove the hard ones. Keep the lifters in order if they are to be reused. Drain the oil then pull the crank pulley, timing cover and the oil pan. Remove the timing gears and chain. Pull the camshaft. Remove the oil pump and drive rod. Before loosening the rod caps, use an engraving tool to ID the rods and caps with the cylinder number they go to. This is preferred to using a number set or center punch, but if done carefully this is still OK to do. Be sure to use only as much force as needed to get a legible number or marking and no more. Mark the caps in the same order as the firing order with a vibratory etcher. If you use a center punch or numbebered punch set, use a light touch so as to not distort anything. Pull off the cap on ONE rod and using a hardwood block, tap out the piston, then return the cap to that rod. Then remove the rest of the rods. Pull the flywheel or flex plate. After marking the main caps for location if needed (some will be marked for position from the factory), undo the main bearing bolts, pull the bearing shells, and with care lift the crank out of the bearing shells and place on the work bench. Make sure that you block the crank so it won't roll off the bench. Nothing worse than damaging a crank when it hits the floor. Wash down all the parts and block. Lightly coat the bearing surfaces with clean oil and coat the engine bores, etc. with ATF, etc. to keep rust to a minimum. Depending on your budget, experience, and preferences, take block and crank to the machine shop for inspection for cracks/defects and for measurements of the bores, main saddles and decks, or inspect and mic the engine yourself using the proper specs. Reasonable care should be taken when moving the block and crank so that they do not become damaged in transportation. If moving them over a long distance it may be better to put the crank back in the engine and bolt it in for the ride, also put the pan on for extra protection. Heads should be secured safely.
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