How do you reduild a Chevy 350 engine?

Answer 1

# Strip it down; in the process, make sure the crankshaft is at #1TDC at the top of the compression stroke and note where the distributor rotor is pointing. # If you have worn through the babbit on any of the bearings (rods OR mains) you'll need to take the crankshaft to a machine shop to have it checked by a qualified machinist who will tell you if it's worn. # While you're at it, drop off the heads. You'll need to have the head planed and the valves and seats ground. You'll also need to have the guides checked and refurbished as necessary. # Drop off the block. The machinist will be able to determine if the cylinders are worn (tapered) If so, they will need to bore the cylinders and you'll need new pistons. # As you're taking it apart, keep track of which lifter went in which hole. If the lifters and/or the camshaft are pitted or worn, you'll need to replace them. If you're planning to improve performance you'll need to replace them anyway. # Using a NEW rebuild kit, replace the timing chain, oil pump and all gaskets. # The machine shop will also be able to clean the engine components far better than you could ever imagine. # You'll want them to replace the freeze plugs. Let them do that for you.

# Also have them press in the camshaft bearings. They're easy to mess up and the shop has the right tools. # Also, have them press the pistons back onto the rods. It's tricky.

Assembly:

# KEEP EVERYTHING CLEAN!!!!! Use compressed air to blow dust and any remaining debris out of the oil journals and off all other surfaces of the engine. # Make sure your torque wrench is properly calibrated.

# Use a good assembly lube on all moving parts. # Make certain that your engine stand can handle the weight.

# With the engine upside down, insert the bearings and TORQUE the crankshaft bearing caps into the specifications that you get from the machine shop. (Use the assembly lube) The crankshaft should turn freely and you should feel NO grit or resistance beyond the viscosity of the assembly lube. This is a good time to install front and rear seals.

# Insert the new pistons and rings following the recommendations of the machine shop or the guidelines of the rebuild kit providers. (The piston mark always goes to the front, and don't put the bearing caps on backward.) Torque the rods to the specifications that you get from the machine shop. Make certain that you have a good ring compressor, that you keep it clean and that you align the ring spaces according to the manufacturers recommendations. Rotate the engine on the stand so that the piston is UP while you're starting the piston into the cylinder, and make sure that the rod does not damage the crankshaft while you're sliding the piston into position.

# Insert the camshaft. # Align the camshaft and crankshaft to the #1TDC position. (see the alignment marks on them both. Put the timing chain on and use a drop of locktite or other thread locking liquid to secure the timing gear onto the camshaft. # Check the head bolts to make sure they turn freely into the block. If there are any burrs or debris that you cannot remove, purchase NEW head bolts.

# Replace the heads using the new head gaskets provided in the kit. Make sure that you follow the head bolt torquing sequence provided by the machine shop. DON'T USE GASKET SEALER ON THE HEADS. # Install the lifters, push rods and rockers. Make certain that you apply assembly lube on lifters and cam and lubricate the rockers. The lifters are hydraulic and should self-adjust. Once all of the rockers are in place, put the rocker covers on using the new gaskets. Apply gasket sealer to ONE side of the new rocker cover gaskets.

# Install the oil pump and sump, and make sure the pressure relief valve is installed properly. # Put on the oil pan using the gaskets provided, gasket sealer on one side of the cork gasket. # Install the flex plate or flywheel. Torque the bolts and use a drop of locktite on each. # Install the timing chain cover... gasket sealer on one side of the cork gasket.

# Install the intake manifold and pay particular attention to the angles. That's where you will most likely develop a leak. # Some people like to put sparkplugs in at this point, just to keep debris from getting into the engine during installation. You can install any other components that you want at this point, but recognize that some may be damaged during installation. It's all your decision. Some people like to put a little paint on the engine to prevent rust. Just make sure you have removed any of the assembly lube that may have dripped to the outside of the engine.

Talk to your machine shop about a good break-in oil. Don't use conventional oil at this point. Many of the shops can recommend a good non-detergent oil that has the best additives for break-in, it all depends on what's available in your area.