A mate of mine has 69 440 HP motor that is supposed to have a forged crank it that is internally balanced but he believes it has an external balancer on it (it's running not in a car). My question is can you correctly identify a forged crank over a cast crank by the size of the flexplate bolts, ie forged uses 7/16" bolts and cast uses 5/16" bolts? If not any advise on how to tell the difference without droping the crank out of the motor? Cheers Gotzy
I dont know how to tell without pulling the pan and looking at it....see this thread for some pics of cast and forged http://www.jalopyjournal.com/forum/showthread.php?t=118441 They all have the same size bolts, although the Hemi cranks and some very early B and RB motors used 8 bolt crank flanges.
I'm pretty sure cast and forged cranks use the same bolts, one way to ID them is by the look of them, cast cranks look pretty clean with even sharp or round edges, while the forged cranks are kind of crude looking, almost like they're made of bone or something. But if the motor is in fact a '69, (ID pad on top of the motor should say "E 440" it is a forged crank motor...Cast cranks didn't start until late '72. Check here to ID your balancer..http://www.440source.com/dampers.htm It could have the "6 pack" rods in it, which required a different balancer which kind if looks like the later cast crank ones.
No 440 cast cranks do not use 5/16 bolts, cast cranks are ext balance and you can use a cast crank motor up to 500 hp without any fear nothing wrong with them up to that point
Easiest way to identify is to post a picture of the vibration damper. I'd like to add some to what was posted earlier: Forged steel crank engines are internally balanced, thus they have a zero balance damper and torque converter (or flywheel). The outer rim of the damper is approximately one inch thick. Cast crank engines are externally balanced, so they have an eccentric weight built into the damper as well as two weights welded to the front of the torque converter. The damper usually has cast into it "use with 440 cast crank only". The outer rim of the damper is approximately two inches thick and has a chamfer on the front as well. The exception to the above is the 440 six pack engine. It has a forged steel crank but is externally balanced due to the heavier "six pack" connecting rods. The damper is different than those used on the cast crank engines. Even if the block is a 1969 engine ("E440" stamped into the ID pad), the crank could have been changed to a cast crank by someone. Engines that had a cast crankshaft from the factory had an "E" suffix after the displacement (i.e. 4T440E) As also stated earlier, the cast crank engines are not inferior for street use. In fact some people prefer them and claim that the cast crank weighs less (so the engine revs faster).
Thanks Guys, I'll get him to drp the pan and check the carnk casting marks. Also found these to links which will help him out. Forged vs. Cast crank - http://www.moparts.com/Tech/Archive/bb/50.html Dampers difference - http://www.moparts.com/Tech/Archive/bb/22.html
Not much wrong with a cast bigblock Mopar-crank. A friend of mine runs 10.9 in the quarter in a manual 4-speed '70 Plymouth with a castcrank-440.
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