Identifying forged vs cast ?
Thread Starter
Melting Slicks
Joined: Aug 2003
Posts: 2,135
Likes: 2
From: Dayton Oh
Identifying forged vs cast ?
I have what I believe to be a cherry numbers matching engine for my 79 L82. Now that I've got the engine disassembled, is there a way to ensure that the rods and crank are OEM forged? I've inspected the crank and no numbers can be found.
Can forged be identified from cast by simply looking at it? If so, does anyone have pics that show the difference.
TIA
Can forged be identified from cast by simply looking at it? If so, does anyone have pics that show the difference.
TIA
Racer
Joined: Feb 2009
Posts: 343
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From: San Diego CA
If I remember, you can tell the crank by looking at the nose. If there's a rift or a line down the centerline of the crank nose then it's a cast crank. No pics but I remember reading that years ago when I was learning to build motors.
Safety Car
Joined: Aug 2000
Posts: 3,711
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From: San Antonio TX
All smallblock Chevy rods are forged. For the crank, look at an unmachined part of the crank, like along one of the counterweights. If the parting line is small, about the width of a toothpick, the crank is cast. If the line is wide, > 1/4" of an inch, this is the forging flash line where the metal was forced out of the dies when it was forged.
Le Mans Master
Joined: Dec 2003
Posts: 5,727
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From: Fremont CA
Real L-82 motor code will be in VIN of Vette, motor should have a oil pan with side baffles and a windage tray bolted to extended main cap bolts. Crank will have a wide forging lines and rods may have paint marks on the beam (nothing really special about the rods, they are like Pink rods and I wouldn't re-use them myself), pistons should be forged. Heads will have pushrod guide plates and 2.02/1.60 valves but, being late light weight castings, unless your going NCRS, throw them into the dumpster as they are prone to cracking. Block is also not as desirable as a 75 or earlier block and should not be used for more than 450HP build-up.
Le Mans Master
Joined: Apr 2007
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From: Graceland in a Not Correctly Restored Stingray
Real L-82 motor code will be in VIN of Vette, motor should have a oil pan with side baffles and a windage tray bolted to extended main cap bolts. Crank will have a wide forging lines and rods may have paint marks on the beam (nothing really special about the rods, they are like Pink rods and I wouldn't re-use them myself), pistons should be forged. Heads will have pushrod guide plates and 2.02/1.60 valves but, being late light weight castings, unless your going NCRS, throw them into the dumpster as they are prone to cracking. Block is also not as desirable as a 75 or earlier block and should not be used for more than 450HP build-up.
They were also known as "crack-o-matics", but if you happen to find you need it, I've got one good 462624 head casting left, bare, dated May 31, 1978 (E 31 8).
TSW
Race Director
Joined: Apr 2000
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Stand it on it's end and rap it with a wrench, if it makes a nice ringing sound it's forged if it doesn't it's cast, or forged and cracked or cast and cracked 
Race Director
Joined: Apr 2000
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
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Team Owner
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From: Crossville TN
Cast surfaces look porous, kind of like sand on the surface, because, well...there was a sand mold that the liquid metal got poured into. Forged surfaces are smooth; they are not 'machined' but there is little surface texture, because a smooth-surfaced die pounded the he!! out of it.
Melting Slicks
Joined: Mar 2008
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From: Meriden CT
All smallblock Chevy rods are forged. For the crank, look at an unmachined part of the crank, like along one of the counterweights. If the parting line is small, about the width of a toothpick, the crank is cast. If the line is wide, > 1/4" of an inch, this is the forging flash line where the metal was forced out of the dies when it was forged.
Look at a ballpeen hammer to get an example of a forging.
Le Mans Master
Joined: Oct 2006
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From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
Look at the front of the crank- right behind the #1 bearing out to the 1st rod journal - if the line is wide it's forged. Narrow is cast. The line runs from the machined bearing surface to the journal.
Burning Brakes
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Burning Brakes
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Drifting
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From: Lubbock TX
