« previous next »
Pages: [1]   Go Down

Author Topic: Painted Numbers Inside Block  (Read 1082 times)

Offline 1970 Snake

  • Sr. Member
  • ****
  • Posts: 424
Painted Numbers Inside Block
« on: December 02, 2019, 01:32:43 AM »
Can anyone advise why the painted numbers in the lifter valley and what they where needed for on my 1970 428 CJ motor.
Logged
Dearborn Built Sept 4, 1969
1970 Mach1 428 CJ R-Code C6
Calypso Coral, White Deluxe Interior
dash tach, front bumperettes
Marti report one of one with delay wipers

Offline RoyceP

  • Hero Member
  • *****
  • Posts: 1536
Re: Painted Numbers Inside Block
« Reply #1 on: December 02, 2019, 09:40:32 AM »
Those numbers are for piston matching at the engine assembly level. The number represents the last digit of the bore size in thousandths of an inch.
Logged
1968 W code 427 Cougar XR-7 GTE Feb 23 Dearborn C6 / 3.50 open
1968 R code 428CJ Cougar XR-7 May 13 Dearborn C6 / 3.91 T - Lock

Offline J_Speegle

  • Administrator
  • Hero Member
  • *****
  • Posts: 24623
Re: Painted Numbers Inside Block
« Reply #2 on: December 02, 2019, 06:58:40 PM »
Quote from: RoyceP on December 02, 2019, 09:40:32 AM
Those numbers are for piston matching at the engine assembly level. The number represents the last digit of the bore size in thousandths of an inch.

+1  And the workers assigned to that task (measuring and marking the bores) were quick!! Seen this demonstrated in a couple of movies made during the era. As expected. Do the same task over and over for days, months or years you get good and fast

Another example

Logged
Jeff Speegle

Anything worth doing is worth doing concours ;)
Pages: [1]   Go Up
« previous next »