ConcoursMustang Forums

1st Generation 1964 1/2 - 1973 - Questions & general discussions that apply to a specific year => 1968 Mustang => Topic started by: bullitt68 on March 13, 2019, 10:06:43 PM

Title: 1968 GT 390 (San Jose) Odd Engine block markings inside block
Post by: bullitt68 on March 13, 2019, 10:06:43 PM

Has anyone seen these markings inside the block before. My engine builder says they were drawn on at the factory to tell the line what pistons to put in the block. FYI this is an original bore block never messed with until now. Any help would be appreciated thanks

Title: Re: 1968 GT 390 (San Jose) Odd Engine block markings inside block
Post by: carlite65 on March 13, 2019, 10:07:54 PM

pics would be nice....

Title: Re: 1968 GT 390 (San Jose) Odd Engine block markings inside block
Post by: bullitt68 on March 13, 2019, 10:11:30 PM

Sorry. Not sure why, but for some reason I am not able to upload the photos. Have been trying for a while on different devices and no luck so far

Title: Re: 1968 GT 390 (San Jose) Odd Engine block markings inside block
Post by: bullitt68 on March 13, 2019, 10:15:12 PM

Quote from: carlite65 on March 13, 2019, 10:07:54 PM

pics would be nice....

Looks like the photo just showed up mysteriously!

Title: Re: 1968 GT 390 (San Jose) Odd Engine block markings inside block
Post by: 70cj428 on March 13, 2019, 10:33:37 PM

Not uncommon, I'm pretty certain the numbers correspond to bore size so they could select fit the pistons ....

John

Title: Re: 1968 GT 390 (San Jose) Odd Engine block markings inside block
Post by: bullitt68 on March 13, 2019, 10:42:31 PM

Thanks John

Title: Re: 1968 GT 390 (San Jose) Odd Engine block markings inside block
Post by: RoyceP on March 14, 2019, 09:56:49 AM

Correct. The pistons were select fitted by the assembler. The bores were inspected after machining and marked so that all the assembler had to do was select the proper size piston / rod assembly to go in each hole.
 

Quote from: 70cj428 on March 13, 2019, 10:33:37 PM

Not uncommon, I'm pretty certain the numbers correspond to bore size so they could select fit the pistons ....

John

Title: Re: 1968 GT 390 (San Jose) Odd Engine block markings inside block
Post by: bullitt68 on March 14, 2019, 10:14:26 AM

Quote from: RoyceP on March 14, 2019, 09:56:49 AM

Correct. The pistons were select fitted by the assembler. The bores were inspected after machining and marked so that all the assembler had to do was select the proper size piston / rod assembly to go in each hole.

Thanks for confirming Royce