Block crayon marks

[BillOhio]

Anyone want to take a guess what this was?
Drivers side front cylinder. Pan rail is at bottom

[Mark]

CK?

[BillOhio]

I thought OK but weird its there

[firstgenaddict]

I have seen DZ and 302 on the block sides in the past.

[rszmjt]

I have a 6,000 mile 70 Z28 engine and CTB can clearly be seen both sides of the block . I too have seen DZ on 302.

[Mark]

Well theres no CK engine suffix for a chevy engine, could be a CR which is a 1958 Corvette 283, or maybe it is an OK.

[Mike S]

 My vote is with 'OK'
It's good to see these marking were done while the engine was assembled and prior to painting over them and surviving today.

Mike

[JohnZ]

All engines had what would ultimately become the stamp pad suffix scrawled on the side of the block in grease pencil; that was done in the first operation on the engine assembly line, where the block was upside-down and the bores were air-gaged. That marking told everyone on the line what innards and external parts to install in the block (cam, crank, rods, pistons, oil pump and pickup, pan, balancer, lifters, heads, intake, water pump, valve covers, distributor, etc.). The pad didn't get stamped until the engine was turned right-side-up and the heads went on.

[Mike S]

Hi John,

 I thought the engine prefix stamp was applied before the heads were mounted which explained why some of the stampings were close to the head to deck edge or under the water plug protrusion as with BB's. Or was it different between BB and SB in regards to when the pad was stamped in relation to the head mountings?

Mike

[BillOhio]

This was on head. Same cylinder

[firstgenaddict]

Here is the engine out of the blue 69 Z I recently restored.

Hi John,

  I thought the engine prefix stamp was applied before the heads were mounted which explained why some of the stampings were close to the head to deck edge or under the water plug protrusion as with BB's. Or was it different between BB and SB in regards to when the pad was stamped in relation to the head mountings?

Mike

Yes, BB were stamped without heads installed, SB with the heads installed

[ZLP955]

Interesting! I was cleaning up a Flint CE block recently and noticed yellow grease pencil marks on one side (which I have left undisturbed); Would the same process as JohnZ described have applied equally to a CE assembly as a production engine?

[BillOhio]

Mine looked to be yellow but I do wonder if they were white that aged?

[JohnZ]

Hi John,

  I thought the engine prefix stamp was applied before the heads were mounted which explained why some of the stampings were close to the head to deck edge or under the water plug protrusion as with BB's. Or was it different between BB and SB in regards to when the pad was stamped in relation to the head mountings?

Mike

On small-blocks, the machine code stamp was done after the heads went on; on big-blocks, the machine code stamp was done BEFORE the heads went on so the stamp could be done on the outboard end of the pad without having the big threaded plug in the head in the way of the gang-holder. Big-blocks had to be done that way so the car assembly plants could stamp the VIN derivative on the INBOARD end of the pad, where there was no plug in the way of the stamp.

[JohnZ]

Interesting! I was cleaning up a Flint CE block recently and noticed yellow grease pencil marks on one side (which I have left undisturbed); Would the same process as JohnZ described have applied equally to a CE assembly as a production engine?

Yes - the only difference was that a "CE" engine was a short-block, so it didn't get heads, an intake, a water pump, distributor, or an oil pan. This made them difficult to handle (had to be done manually with hi-lo's and wooden pallets when they got to the end of the line), so they were usually run on weekends.