© Restoration Guide

Appendix C - Part 1/Engine Assembly Process

The engine assembly process at both the Flint, MI. and Tonawanda, NY. engine plants varied slightly due to differences in their standard operating procedures. The assembly process shown here is general in nature and does ot go into great detail for each step at each engine assembly plant. One caveat here: today's engines built at the two plants are very different from those plants in the early 70s. Modern robotics and new technologies have emerged.

The following assembly for Flint and Tonawanda engine plants is general in nature as small variations were usually made from year to year.

Flint	Tonawanda
Raw castings enter plant	Raw castings received from other parts of Tonawanda engine plant
Block machining (boring/broaching) in 1 to 2 days and washed	Block machining (boring/broaching) and washed
Block begins upside down. Bore sizes on oil pan rail broadcast ahead to piston hook up area.	Oil galley plugs
Galley plugs	Transmission alignment pins
Camshaft	Camshaft
Main bearing caps removed, crank installed, caps reinstalled.	Main bearing caps removed, crank installed, caps reinstalled.
Flywheel & pressure plate or flex plate	Flywheel & pressure plate or flex plate
Cam & crankshaft gears, timing chain	Cam & crankshaft gears, timing chain
Piston installation	Piston installation
Front engine cover and seal	Front engine cover and seal
Harmonic balancer	Harmonic balancer
Oil pump shaft and oil pump	Oil pump shaft and oil pump
Windage tray bolts if applicable	Windage tray bolts if applicable
Oil pan and hardware	Oil pan and hardware
Clutch housing	TDC determined, timing pointer
Engine turned upright	Engine turned upright
TDC determined, timing pointer	Camshaft lifters
Camshaft lifters	Build date/suffix code stamped *
Cylinder heads installed	Cylinder heads installed
Rocker arms & balls installed	Rocker arms & balls installed (studs already installed)
Intake manifold installed (oil filler tube if applicable, water outlet, thermostat, and lifting brackets already affixed)	Valves adjusted
Valves adjusted	Intake manifold installed
rocker arm covers installed	Water outlet & thermostat installed
Miscellaneous brackets and switches installed	Water pump installed
Build date/suffix code stamped	Spark plugs installed
Water test with vacuum gauge	Distributor installed
Oil cavity test	Miscellaneous brackets installed
Paint assembly	Exhaust manifolds
Distributor installed	Vacuum test
Coil & plug wires	rocker arm covers
Spark plugs	Paint assembly
Temperature switches	Hot test
Water and oil drained	Water and oil drained
Exhaust manifolds installed	Racked & readied for shipment
Spark plug wire supports, heat shields, other miscellaneous brackets installed
Component verification
Racked & readied for shipment

* Early (1965) 396-cid big block engines date/suffix code were stamped further to the right on the engine pad due to the large plug in the end of the cylinder head after assembly at Tonawanda. This caused problems for the final assembly plants in stamping the partial VIN identification. Later the engine ID information was stamped on the left of the pad before the heads were installed allowing the right side of the engine pad to be used for the car's partial VIN to be stamped.

All small-block (283/307/350/400) V8 engines have the date and suffix code stamped on the right portion of the engine pad as you face it in the car. The final assembly plant partial VIN stamp would be stamped to the left side of the engine. All I6 engines have this data stamped on a machined pad by the distributor.

The broach cutter above on the left broaches the pan rail and the upper half of the main bearing bores. The block is flipped over, registered and clamped on the pan rail, and the one on the right broaches the deck surfaces and the top horizontal surface between the decks. Each lateral row of cutting blades in each broach is set about .001" deeper than the row ahead of it. The block is clamped solid on its pallet and the overhead broach has about a six-foot stroke longitudinally across the block surface; one pass for the pan rail and one pass for the decks and top and it is done. Fresh blades in the tool left hardly any broach marks at all; as the blades wore, the broach marks became more visible.

Early engines shown here are painted and prepped for shipment to GM's final assembly plants. Note the exhaust manifolds were not masked for painting; the paint was soon burnt off when the engines were fired for the first time. Note early small-block V8s were shipped with the distributor installed. Due to emission standards in the 70s, the distributor was installed at the final assembly plant for all engines. Also note the early-style bellhousing that bolted to the frame (1955-1957) and was not painted.

For engines assembled in the 70s, if it was to have an automatic transmission a flex plate was installed; if it was to have a manual transmission a pilot bushing or bearing was pressed into the end of the crankshaft and the bellhousing was installed.

On the engine dress line at the final assembly plant, all the necessary accessories were installed such as fan, various water connections, alternator, A/C compressor if applicable, carburetor, A.I.R. components if applicable, spark plugs, etc.

1970 Chevelle SS396/SS454 Build Sheet Decode Program

1964-1972 Ship Manuals & Parts Catalog

1953-1972 Chevrolet Production Numbers