QK code 409?
- Thread starter Carl 1962
- Start date
Its usually the resistance to movement in the cylinder and deck area that causes those freeze cracks, the ice in the jackets is pushing against the outer wall of the block and the deck surface is trying to prevent that movement so the outer wall cracks at its weakest point which is usually just below the deck area, this is where the OP block cracked and was repaired. The danger of movement is most when the block is heated to repair it, so it is a good idea to check for it. If the engine was run after the repair with no isssues it would lead me to believe that there couldn't have been too much movement. I've got a 348 block that had a braze repair to a crack in the same spot and then was run for long enough to wear out the rebuild that was done when the crack was repaired.
My block started seeping a few years ago. It definitely DID NOT FREEZE. I lightly ground it out and fixed with JB weld. Still in the car, not seeping.
Anyone else have similar experience not due to freezing?
I would bet a lot of these blocks never froze. There is a weak spot along there in the casting.
Anyone else have similar experience not due to freezing?
I would bet a lot of these blocks never froze. There is a weak spot along there in the casting.
I would agree. I sonic checked one in that area and it was only .100. The rest of the side was thicker.
^^^^^^^^^^
That's exactly why I run low horsepower....
That's exactly why I run low horsepower....
Sounds similar to the Cummins 6BT 53 block, they would just develop a crack in a certain area of the block, it was so prevalent that lock n stitch developed a kit tailored specifically for that repair.
Tooth has a looong way to go to catch you, but you are making me nervous running this old junk!
Jeff
That block may be in someone's car on this site as it was in Gibbs Ca. shop at the time, somewhere around 14/15?
So that's the reason, I wondered.....^^^^^^^^^^
That's exactly why I run low horsepower....
Carl 1962
Well Known Member
To bring closure to this mystery, according to Chevrolet production information provided by Warren Leunig, apparently in very late 1962 production, the suffix code QB was replaced by QK for RPO587. At some point in late 62 production, the date code also changed from the usual month, day, year (eg D 3 2 meaning April 3rd 1962) to the Julien date code, and this block has Julien date code 182, meaning July 1st 1962.
This applies to late 1962 409/409 only because in 1963 production, the QB code was re-introduced.
This applies to late 1962 409/409 only because in 1963 production, the QB code was re-introduced.
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Good work Carl.
What does the LD and EXP mean in the 409" listing?
What does the LD and EXP mean in the 409" listing?
What document is that? I don't have that in my Tonawanda. Collection.
Carl 1962
Well Known Member
I got a couple of computer screen shots of what looks like a scanned PDF from Warren Leunig, but I'm not sure what the pages were from. I'll ask him what they're from and ask for a copy. They didn't mean much to me because they're just a long list of part numbers and beyond my research focus so I cannot confirm what LD and EXP mean, but your guess sounds right.
