Block casting date vs. engine assy. data

[Steve Antonucci]

Hi everyone,

I have long been interested in the discrepancies found between a particular
engines assembly date and the casting date of its cylinder block. The years
of production I am mostly interested in here would be from 1967 to 1972.

I personally own an L/78 engine that I purchased from its original owner and
the spread between the blocks casting date and the engines assembly date is
nearly six (6) months. I know this is a stretch by most standards. Recently,
I learned of a fellow with a late production '68 Corvette that had a block with
a casting date nearly nine (9) months before the assembly of the engine. These
are just two examples of what I suspect are many.

So, my questions here concern the assembly process at Tonawanda, and possibly
other assembly plants, and why some engines have a few days between block
casting dates & assembly dates and others have many months respectively.

Based on the many informative discussions I have been involved in here, I truly
believe Corvette owners tend to be the keepers of such information. Few other
forums seem to be concerned about topics such as this. Now that I have buttered
your bread, I would like to open this topic up to dicusssion.

Can anyone tell me the process ( roughly ) involved with casting the cylinder
blocks and how that related to the assembly process? I have a fairly good idea
about how the blocks were machined, but I don't have much information about
the block casting process itself. Where exactly were the blocks cast? How
were raw blocks ( un-machined ) delivered to the assembly plant(s)? By train,
truck, etc.? How long did this "delivery" process take?

Did blocks just sit around in racks ( or pallets ) waiting to be assembled?
Could some blocks have been pushed to the back of the stack just based on
physical location? What else could possibly account for a date variance of 6
or 9 months in the engine assembly process?

As many of you well know, we "play" in a hobby that has a lot of popular wisdom
applied to it. Popular wisdom referes to commonly held beliefs. As one that
has been involved in production for many years, I know that nothing is ever cast
in stone and that most manufacturing facilities rarely throw usable items away.
Indeed, the saying, "The General didn't throw anything away" has been stated
many times to me. As a matter of fact, I first heard this from a long-time,
multiple Corvette owner.

Steve

[John H.]

Re: Block casting date vs. engine assy. data

Steve -

At Flint Engine, their blocks were cast at the Saginaw Foundry, and took a 45-minute ride in a dedicated fleet of special GM trucks that ran 24/7 from Saginaw to Flint and back. If you consider all the castings Saginaw supplied to Flint Engine (blocks, heads, intakes, water pumps, flywheels, camshafts, etc.), Flint handled over 50,000 iron castings every single day to build 5,500+ engines per day. Machining ran on three shifts, and assembly on two, producing one finished engine every twelve seconds on the assembly shifts.

The Tonawanda foundry was on the same piece of property as Tonawanda Engine; castings only had to move across the yard, and volume was the same as at Flint Engine.

Occasional long spans from casting date to assembly date were most likely due to in-plant repairs (taps or drills broken off in holes, etc.) that were set off to the side and got lost in the shuffle waiting for repair manpower to get to them, or they could also be assembly plant return engines that sat for the same reasons before they could be torn down and repaired/rebuilt.

[Steve Antonucci]

Re: Block casting date vs. engine assy. data

John,

The repair scenario you mentioned makes more sense than anything I've heard
thus far. Do you think the blocks in question could have sat around for that
many months prior to being addressed? Again, I have absolutely no reference
material on the engine manufacturing process from back in the day.

Steve

[Loren L.]

In addition to John's factors, another could be

the rarity of the motors - in '67, it would not be surprising to me to see a longer lead time on L88 & L89 motors, due to lack of demand and the possibility that these motors might have been built in batches. Another possibility would be extremely late motors - a car ordered with 365HP A/C & TI where they discover that there are NO SUCH motors in the engine room - solution? Grind off the reglar 365 suffix letters and insert the TI engine codes.

[Loren L.]

In addition to John's factors, another could be

the rarity of the motors - in '67, it would not be surprising to me to see a longer lead time on L88 & L89 motors, due to lack of demand and the possibility that these motors might have been built in batches. Another possibility would be extremely late motors - a car ordered with 365HP A/C & TI where they discover that there are NO SUCH motors in the engine room - solution? Grind off the reglar 365 suffix letters and insert the TI engine codes.

[Steve Antonucci]

Re: In addition to John's factors, another could b

Loren,

Has such a situation ever happened before?

Steve

[john daly]

Re: In addition to John's factors, another could b

Steve,
There was an excellent article in the restorer a few years ago written by Al Grenning about exactly the same situation Loren describes with base engine 67's late in the model year.

jd

[Tim G.]

Re: In addition to John's factors, another could b

Steve, mine was the '68 block with a nine month spread. Casting date of 10-17-67 and build date of 07-17-68. The fact that this is a very late car contributes to some of the reasons that they may have wanted to use up these blocks. The car was number 266XX built 7-24-68. The block may have been in a repair station for some time and they pushed it out to complete 1968 production. I never had a question about the engine, it was a one owner car from new until 1990 and I saw it many times in the original owners hands with its original engine.

[Steve Antonucci]

Re: In addition to John's factors, another could b

Tim,

I'd still like to know about the "repair station" scenario. How often were
such blocks repaired? Were they done in batches? I'd guess probably yes.

Steve

[Tim G.]

Re: In addition to John's factors, another could b

Nolan Adams often wrote about the repair stations. I believe that they were done in batches as time permitted. I'm sure that at the end of the year they were really trying to get the current inventory used up. I'll point out that this engine had all late dated components aside from the casting date of the block.
It was certainly near the end of '68 production and they may have been wanting to exhaust all of the '68 casting number blocks in inventory.