Terry,
Thank you for your kind words…I appreciate it.
“I wrote a story for The Restorer about that tour, but I would have to rely on Vinnie to pull it from the old files.”
Your article is in Vol. 18 #3 Winter 1992…excellent read with excellent photos BTW.
The 1980 “Casting a Cylinder Block” link below provides a good sequential overview of how a block is cast, including a good discussion of the cope and drag molds – as well as what follows. It’s 20 minutes long, but well worth watching IMO.
Some highlights marked by time into the video follow:
around 2” or so starts the core making process
~5” mixer/muller for sand composition and preparation is followed by the cope and drag loading discussions
@ 7” to 8” you can see the voids between the cores and the sand where the metal will flow and solidify for the case
~12” mold pouring. This is much less automated than what I saw (hand pouring vs machine-operated), but the concepts of how the metal gets into the mold are the same
~12:35 cope and drag separation
~13:28 shakeout table – LOUD; hot; and dirty !
~14” runner knockout
~14:30 Fettling station
~15” Shot blasting
~17” head facing milling
~19” registration holes for down-line machining operations
Also, re-thinking about the Roll-Test 1st then to Toe-in 2nd sequence, I suppose one advantage of doing it that way might be various front-end suspension components could "settle-in" (get jounced ?) as the wheels were first rotated up to 60 mph. Here’s what John H. had in his C2 Assembly Process Presentation (available in the Database of Restoration Documents [DoRD] Sticky Post)…
Thank you for your kind words…I appreciate it.
“I wrote a story for The Restorer about that tour, but I would have to rely on Vinnie to pull it from the old files.”
Your article is in Vol. 18 #3 Winter 1992…excellent read with excellent photos BTW.
The 1980 “Casting a Cylinder Block” link below provides a good sequential overview of how a block is cast, including a good discussion of the cope and drag molds – as well as what follows. It’s 20 minutes long, but well worth watching IMO.
Some highlights marked by time into the video follow:
around 2” or so starts the core making process
~5” mixer/muller for sand composition and preparation is followed by the cope and drag loading discussions
@ 7” to 8” you can see the voids between the cores and the sand where the metal will flow and solidify for the case
~12” mold pouring. This is much less automated than what I saw (hand pouring vs machine-operated), but the concepts of how the metal gets into the mold are the same
~12:35 cope and drag separation
~13:28 shakeout table – LOUD; hot; and dirty !
~14” runner knockout
~14:30 Fettling station
~15” Shot blasting
~17” head facing milling
~19” registration holes for down-line machining operations
Also, re-thinking about the Roll-Test 1st then to Toe-in 2nd sequence, I suppose one advantage of doing it that way might be various front-end suspension components could "settle-in" (get jounced ?) as the wheels were first rotated up to 60 mph. Here’s what John H. had in his C2 Assembly Process Presentation (available in the Database of Restoration Documents [DoRD] Sticky Post)…
| RTTI | Roll Test (RT) and Toe-In (TI): |
| RT-1 | Driver locates car in the roll-test machine and pushes button on pedestal to start machine cycle; front and rear car-width rollers rise up so all four wheels are on the rollers, and driver accelerates. Rear wheels drive the rear roller, which in turn drives the front roller so all four wheels turn at the same speed. The left side of the rollers are smooth, and the right sides have raised sections to simulate a bumpy road. |
| RT-2 | Driver accelerates through the gears to 60 mph, listening for any unusual noises, and compares speedo reading to the machine’s overhead speedo dial to ensure correct speedo gear is installed. Driver slows to 30 mph and exercises lights, wipers and washers, radio, turn signals, horn, hazards, and moves over to the “rough road” side of the rollers to check for vibration, squeaks and rattles. |
| RT-3 | Driver moves back to the smooth-road side of the rollers, accelerates to 60 mph, and applies parking brake several times to “burnish” the shoes prior to final cable adjustment. Driver then slows to a stop on the rollers and pushes the button on the pedestal; the rollers retract and the driver proceeds into the toe-in machine. |
| TI-1 | Car is driven into the Toe-In machine and driver attaches steering wheel lock/level tool to wheel and top of door. Pit operator cycles machine, which moves locating rollers on floating heads against inside and outside of tires and machine spins the front wheels. |
| TI-2 | Watching dials on his control panels, pit operator turns tie rod adjusting sleeves until dials indicate that toe-in is within specifications while steering wheel is held level and straight-ahead; he then positions tie rod clamps correctly and tightens clamp bolts with an air tool and a wrench. Driver removes steering wheel tool, hangs it on pedestal, and proceeds into Final Process Repair for any needed adjustments. |
I recall the Tonawanda people told me that due to the necessity of keeping the furnaces heated and in operation, if the casting orders were minimal their operation continued at a minimal pace and those castings were stored in the Pearce Arrow Warehouse for later machining as the Assembly Plant orders increased. This practice lead my contact to dismiss our reliance on rigid date progression. This was only one of his negative comments about our judging practices.
I saw John Hinckley's description of the roll test in the referenced product. My only explanation for my different recollection is that we are talking about different times in Corvette production. My description might have been during either earlier C2 or even C1 production.
John does state that the toe setting operation followed the roll test, confirming the statement of the former employee.
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