Information needed on this block

he explained it in the add, when blocks are cast the molten metal can shift locations in the casting mold slightly, the machinery that machines the block is all indexed off
specific locations as its held in place, this results in some variation in the resulting casting thickness if the core mass has shifted marginally , thus most machine shops vastly prefer to work with ,
castings that maximize all casting metal thickness, in all directions from machined surfaces.

http://www.project33.com/Categoryarticle.cfm?ID=13&Category=Engine

cores2.jpg


cam bore machined off center on casting ,like the picture linked below , unlike the one centered above, is a good indicator bore wall thickness is not consistent
cores32.jpg

cores4.jpg

cores3.jpg

core shift results in one side of the cylinder bore walls tending to be noticeably thinner than ideal, this results in un-equal stress and more failures
cores1.jpg

cores1.jpg

torqueplt1.jpg
 
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Interesting. I learned something new today.


I just noticed the casting numbers are the same as those on a block I sold last year, that was out of a 92 Iroc Z/28.
 
Price is right.
It's from a 1 Ton Truck because it has 4-bolt mains.
Actually Rare.
Won't lose money on it.
Flip it easy.

Callaway used the same 4-bolt block in all Twin Turbo C4 Covettes.
All had 600-700 ft/lbs boost torque at the flywheel.
 
Is this “core shift” something that happens on other motor castingsor just GM small blocks? If there is a shift to the left or right wouldn’t that screw up measurements upon assembly? Is it an accurate assumption that There could be some core shifting even worse than the photos above and those castings were used anyway?
 
chromebumpers said:
Is this “core shift” something that happens on other motor castingsor just GM small blocks? If there is a shift to the left or right wouldn’t that screw up measurements upon assembly? Is it an accurate assumption that There could be some core shifting even worse than the photos above and those castings were used anyway?
Click to expand...
More prevalent on Chevy engines core shift.
See it alot on China made casted parts too.
Seen it a bunch on China intakes made for Pontiac V8.

Factory blocks and heads wise it goes like this.
Cadillac 500 V8 ultra high quality.
Olds V8 425 Top notch like Caddy.
Muscle era Olds V8 330-455 to 1971 excellent.
Pontiac V8 1955-1974 Excellent.

Chevy can be all over.
Deemed to be low scale car new.
Except for Corvette.
World Class car.
Blocks from Corvette original should be the very Best Chevy had.

Big Block Chevy made all to be top notch.
 
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