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alhewitt
11-29-2017, 07:11 AM
I’m trying to understand the relationship between the cast raised date codes on the driver’s rear side of our engines to the stamped engine code on the passenger’s front pad to the actual date the car was made. How much time would have elapsed?

Engine blocks have a part number cast into them and located at the passenger’s rear side of the engine, this part number tells us the years and cars it was found in. Then there is then the cast date code as described above telling when the engine block was actually made (cast). I believe I know how to read the date codes with letters corresponding to months of the year followed by numbers relating to the day of month that the block was made or cast. My question is when was the stamping done? How much time would have elapsed from the date that the engine was made per the casting codes to when it was finally assembled and then how much time for the engine to get to the assembly plant and installed in a car? Was the stamping done on the day the engine was assembled or when the engine found its way into a car?

I don’t know enough about the stamping process, when and where it was done. My gut feeling says the stamping was done during engine assembly in some plant in Michigan. It then was sent to the car assembly plant. This had to be a logistics nightmare with so many different engines available with so many different stamping.

Thanks, Al

BamaNomad
11-29-2017, 07:40 AM
1. You seem to understand the 'casting dates' and Casting numbers. But there is also a 'shift' identified in the casting symbols which tells which part of the day (shift) it was cast.

2. The application code stamping was done in the engine plant after machining when the engine was assembled; it's the 'parts' in the engine that determine the application stamping code.

3. The timing between casting and machining/assembly varies depending on some variables, but generally they don't let the castings sit around unless there is an issue of some kind. Example: I've an original 57 BelAir with 283 engine that I've had since 1978. I rebuilt the engine in 1999 when it had just under 100K miles - no part of it had ever been disassembled, as every bolt/nut/fastener was factory correct! I was amazed to find that the engine was CAST and ASSEMBLED on the same day! I can only assume the casting took place in an early shift and the engine was machined/assembled much later in that same day! I've another original engine in a '69 Z28 that I've owned since 1976. The block was cast on 26Aug69 and assembled on 27Aug69, which seemed close until I found the dates for my '57 engine! :) Basically the plants operated on the basis that parts didn't 'sit around' as there was not enough space to store them; the parts moved in, got assembled, then moved out.

4. Re 'WHEN' was the engine put into the vehicles? I think I have all the data for the two cars identified above which I will list here. (Note that NCRS in their strict judging guidelines allows for up to 6 months between engine assembly and vehicle completion date, but that would be an extreme example and only due to some specific 'problem' encountered with that engine)

- 1957 '283' engine: Cast: 18Jan1957, Assembled: 18Jan1957, Car completed (in Atlanta, GA) on: 25 Jan 1957.
- 1969 '302' engine: Cast: 26Aug1969, Assembled: 27Aug1969, Car Completed (in Norwood OH) on 18 Sept 1969.

Both engines were cast/machined/assembled at the Flint Michigan engine plant, then shipped to the final GM assembly plant. There was a second engine plant used by Chevrolet at Tonawanda, NY which had responsibility for all 'big block engines' and some non-high performance small blocks. Flint had responsibility for all high performance small block engines, and also non-high performance small blocks.

PS. Even back during the 'tri five days' ('55-57) Chevy and most plants were building 'to order'; the various supply plants were provided orders for the parts they produced based on their estimated needs and dates (based on the orders). Typical time from 'Order' to delivery ranged from 1-2 months. note that *most orders' were orders from dealers for vehicles to go onto their lots and were made in groups.. Individual 'sold item' orders got precedence during the build process (and that's where the 1-2 months come from)...

PPS. For engines that also received VIN stampings (not in 1957 but true in 1969), the VIn stampings were made just as the engines/trans were going into the specific vehicle (when the VIN was known).

alhewitt
11-29-2017, 08:30 AM
Great info BamaNomad and thanks for responding with the tutorial. Al

LEE T
11-29-2017, 03:00 PM
I have bought and sold a lot of original California built 57s, and the stamped date on the engines were about 2 weeks ahead of production dates. Those engines came from Flint Mi. I don't think a railroad box car goes straight thru even today.