Engine Assembly

[Ray C.]

Could someone please describe the engine process from casting to install in a Corvette? Were the engines for different horse powers assembled, pads stamped with the assembly date and suffix, and then drawn from inventory for a particular car that required that engine, or would the engine be built from scratch as the car proceeded down the assemble line. Would the vin number then be stamped on engine pads after mid to late 1960 .

Thanks for any information.

Ray #36314

[John H.]

Re: Engine Assembly

Ray -

That's more typing than I want to do here, but you'll find my complete photo-illustrated article on engine build at Flint V-8 in the May '05 issue of "Corvette Enthusiast" magazine, and another article on the St. Louis engine dress line in the June '05 issue. Send me your e-mail address and I can send you the text of both articles.

In short, the engine was built at Flint V-8 (or Tonawanda for BB's) for a given suffix application, pad-stamped with the date and suffix, shipped to St. Louis, and pulled from the rack and hung on the dress line when that suffix was called for. After the transmission was attached, the car's VIN derivative was stamped on the pad and the trans, and engine dress proceeded.

The engine was "bare-naked" when it left the engine plant - everything you don't see in the 1955 photo below was added at St. Louis.

[John H.]

Re: Engine Assembly

Ray -

That's more typing than I want to do here, but you'll find my complete photo-illustrated article on engine build at Flint V-8 in the May '05 issue of "Corvette Enthusiast" magazine, and another article on the St. Louis engine dress line in the June '05 issue. Send me your e-mail address and I can send you the text of both articles.

In short, the engine was built at Flint V-8 (or Tonawanda for BB's) for a given suffix application, pad-stamped with the date and suffix, shipped to St. Louis, and pulled from the rack and hung on the dress line when that suffix was called for. After the transmission was attached, the car's VIN derivative was stamped on the pad and the trans, and engine dress proceeded.

The engine was "bare-naked" when it left the engine plant - everything you don't see in the 1955 photo below was added at St. Louis.

[Ray C.]

Re: Engine Assembly

Thanks! John

ray63@rochester.rr.com

Ray

[Ray C.]

Re: Engine Assembly

Thanks! John

ray63@rochester.rr.com

Ray

[Duke W.]

Re: Engine Assembly

One could probably write a book on the subject.

The St. Louis plant had about one month's visibility based on their order book, so they ordered engine configurations from Flint based on their order book and historical demand data. The engines were shipped to St. Louis ASAP. Flint did not maintain a finished engine inventory - St. Louis did.

But the bigger problem was how many forged pistons did Flint need from TRW for SHP/FI engines. Such individual parts planning has to be done much further forward in order to build tooling for anticipated production volume.

It's the same game today, but modern computer information systems provide better, more timely order/production data to allow less inventory investment. However, if customer demand for some option exceeds anticipated levels, "production constraints" have to be applied, so if you order a new Corvette with a constained option, it will take longer to get into the production schedule, or it might not even be built.

Back to the fifties and sixties - popular engines such as base and popular options typically have Flint production dates from less than a week to a couple of weeks before the vehicle production date, but low volume engine options such as the 283-250/275 typically have more dispersion because they spent more time in inventory until they were consumed by a production order.

Based on prior annual demand for the 283/250 St. Louis might have ordered ten of these engines from Flint for the next month, but that month might have seen only 5 built and the next month could have been 15, so some second month production could have used "left over" engines from the previous month and the engine-car build date dispersion could be 2-6 weeks.

The new ZR-1 will be constrained to about 2000 per year - not due to engine production limitations, but due to the carbon fibre top panel. More than 2000 per year would require significant additional tooling expense. They could make the investment and build/sell, say 4000, but then the next year demand might dry up because there are a limited number of people with $100K+ to spend on a sports car.

I think it was Ed Cole who was once quoted as saying something along the lines of: "Sports cars, yeah, I love 'em. The only trouble is I have to sell 'em all the first day."

GM tooled up and ran two shifts at Bowling Green to build over 50,000 1984 Corvettes, and they sold quickly. There was a lot of pent up demand for a new Corvette, but it was satisfied over the next few years and demand/production dropped off to less than 25,000 in 1988. Monthly production didn't drop that much because the 1984 model year lasted for about 18 months, but GM still eventually laid off the second shift, and IIRC the UAW contract required that they pay the laid off workers a full year of wages and benefits.

GM did not make the same mistake with the C5.

Duke

[Duke W.]

Re: Engine Assembly

One could probably write a book on the subject.

The St. Louis plant had about one month's visibility based on their order book, so they ordered engine configurations from Flint based on their order book and historical demand data. The engines were shipped to St. Louis ASAP. Flint did not maintain a finished engine inventory - St. Louis did.

But the bigger problem was how many forged pistons did Flint need from TRW for SHP/FI engines. Such individual parts planning has to be done much further forward in order to build tooling for anticipated production volume.

It's the same game today, but modern computer information systems provide better, more timely order/production data to allow less inventory investment. However, if customer demand for some option exceeds anticipated levels, "production constraints" have to be applied, so if you order a new Corvette with a constained option, it will take longer to get into the production schedule, or it might not even be built.

Back to the fifties and sixties - popular engines such as base and popular options typically have Flint production dates from less than a week to a couple of weeks before the vehicle production date, but low volume engine options such as the 283-250/275 typically have more dispersion because they spent more time in inventory until they were consumed by a production order.

Based on prior annual demand for the 283/250 St. Louis might have ordered ten of these engines from Flint for the next month, but that month might have seen only 5 built and the next month could have been 15, so some second month production could have used "left over" engines from the previous month and the engine-car build date dispersion could be 2-6 weeks.

The new ZR-1 will be constrained to about 2000 per year - not due to engine production limitations, but due to the carbon fibre top panel. More than 2000 per year would require significant additional tooling expense. They could make the investment and build/sell, say 4000, but then the next year demand might dry up because there are a limited number of people with $100K+ to spend on a sports car.

I think it was Ed Cole who was once quoted as saying something along the lines of: "Sports cars, yeah, I love 'em. The only trouble is I have to sell 'em all the first day."

GM tooled up and ran two shifts at Bowling Green to build over 50,000 1984 Corvettes, and they sold quickly. There was a lot of pent up demand for a new Corvette, but it was satisfied over the next few years and demand/production dropped off to less than 25,000 in 1988. Monthly production didn't drop that much because the 1984 model year lasted for about 18 months, but GM still eventually laid off the second shift, and IIRC the UAW contract required that they pay the laid off workers a full year of wages and benefits.

GM did not make the same mistake with the C5.

Duke

[Ray C.]

Re: Engine Assembly

Thanks! Duke & John

Let see if I understand the above posts correctly. A small block engine would be cast in Saginaw and then shipped to Flint for machining and assembly. (from one to ? days after casting) The engine assembly date, "F" for Flint and suffix code would be stamped into the pad after the engine was built (heads on engine) and prior to shipping to St. Louis. The engine was designated for a particular application. Base, 2X4 with hydraulic lifters or high horse power engines. The quantity of engines types ordered was determined by past order history and projections, with an engine inventory at St. Louis. By viewing the picture provided by John, it looks to be a LIFO (last in first out) inventory system. A high horse engine, or for that mater any engine could set in inventory for days or weeks, or could be placed in a car right after entering inventory. The vin number would be stamped on the block (late 1960) when it was mated to the transmission and allocated to a particular Corvette on the assembly line.

Thanks again for the information!

Ray #36314

[Ray C.]

Re: Engine Assembly

Thanks! Duke & John

Let see if I understand the above posts correctly. A small block engine would be cast in Saginaw and then shipped to Flint for machining and assembly. (from one to ? days after casting) The engine assembly date, "F" for Flint and suffix code would be stamped into the pad after the engine was built (heads on engine) and prior to shipping to St. Louis. The engine was designated for a particular application. Base, 2X4 with hydraulic lifters or high horse power engines. The quantity of engines types ordered was determined by past order history and projections, with an engine inventory at St. Louis. By viewing the picture provided by John, it looks to be a LIFO (last in first out) inventory system. A high horse engine, or for that mater any engine could set in inventory for days or weeks, or could be placed in a car right after entering inventory. The vin number would be stamped on the block (late 1960) when it was mated to the transmission and allocated to a particular Corvette on the assembly line.

Thanks again for the information!

Ray #36314

[Jack H.]

Re: Engine Assembly

(1) The trip from Saginaw to Flint is about 40 miles and GM inter-plant trucks made constant cartage trips. Engines have been known to have been cast on one shift, transported to Flint the next and actually gone down the assy line that same day!

(2) GM had NO specific inventory control system (FIFO, LIFO)... Sometimes fresh incoming parts went directly to the line. Other times they'd go to inventory and be pulled rather randomly. Plus, there WAS that rare instance where this/that failed/broke, was set aside, and then re-worked at a later date and returned to inventory....

(3) Yes, VIN derivative stamping was done at St. Louis when the engine was 'dressed' to be installed in a given car. That's when other 'bolt on' components (fuel pump, carb, starter, alternator/generator, Etc.) came out of inventory for that particular engine.

Basically, (trust this +98% of the time) if you see the component called out in your copy of the AIM for assy, then it wasn't part of the engine sub-assy that was manufacturered by Flint/Tonawanda... It the component is shown in the AIM, but there's no PN for it on the drawing, then it came with the engine sub-assy.

[Jack H.]

Re: Engine Assembly

(1) The trip from Saginaw to Flint is about 40 miles and GM inter-plant trucks made constant cartage trips. Engines have been known to have been cast on one shift, transported to Flint the next and actually gone down the assy line that same day!

(2) GM had NO specific inventory control system (FIFO, LIFO)... Sometimes fresh incoming parts went directly to the line. Other times they'd go to inventory and be pulled rather randomly. Plus, there WAS that rare instance where this/that failed/broke, was set aside, and then re-worked at a later date and returned to inventory....

(3) Yes, VIN derivative stamping was done at St. Louis when the engine was 'dressed' to be installed in a given car. That's when other 'bolt on' components (fuel pump, carb, starter, alternator/generator, Etc.) came out of inventory for that particular engine.

Basically, (trust this +98% of the time) if you see the component called out in your copy of the AIM for assy, then it wasn't part of the engine sub-assy that was manufacturered by Flint/Tonawanda... It the component is shown in the AIM, but there's no PN for it on the drawing, then it came with the engine sub-assy.