Coming in late on the crank dicussion. Milton, your right about the forged crank being the "best" due to the grain structure, but I think you explaination can use a little tweek: It is not linear in the hot billet (pre-forged) form, but becomes linear with the mechanical compression and forming in the actual forging part of the process. The linear structure is thus mechanically formed. And the increased strength results in the direction perpendicular to grain direction, which is just where we want it.
Actually, cranks *could* be cast in steel with higer strength than cast ductile (nodular) cranks, but if you're going to steel, you may as well forge them for even better strength. Kurt mailto:[EMAIL PROTECTED] http://wmachines.shubes.net '65 Jetstar 1 (4-speed) '66 442 Sports Coupe (Tri-Carb, 4-speed) '67 442 Convertible (4-speed) '69 442 Convertible (3-speed manual) '92 Achieva SCX W-41(5-speed) '04 Expedition (no-speed) > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Infinite Space > Systems, Inc. > Sent: Thursday, August 10, 2006 5:49 PM > To: [email protected] > Subject: Re: modified verses stock, was Re: opinions wanted on value of > 69 Cutlass ragtop > > > Joe, > > > Also, I started that conversation to see if I could get the list moving. > Not enough tech stuff for me lately. to much fluff and a lot of guys > were complaining off list. I think it helped a litle. > > > I can help with that, too. :-))) > > > > Now I am sick of the word Billet in the aftermarket. Half the > people out > > there don't even know what it means. > > > You are soooooooo right it simply can't be said enough. If I had > a choice, > right this minute, between a forged steel crank for a 455 Olds > and a billet > steel crank for a 455 Olds, I'd take the forged, unless the > billet crank was > a very high quality 4380 or better alloy steel that was made into > a billet > either in the USA or Western Europe. Even though the forged > steel crank is > only a 1000 series steel alloy, probably a 1050 or 1075 (which > isn't as near > as tough as a 4000 series chromoly steel alloy), the simple fact > the grain > structure of the steel in a forged steel crank flows through the > crank in an > uninterrupted pattern makes it far stronger than the machined cut through > and terminated flow in a crank machined out of an alloy steel billet. The > only time the billet crankshaft catches up to the OEM factory > forged steel > crank is when the steel alloy goes over the 4000 mark, at least > in the high > 4000s and preferably into the 5000s or 8000s. An 8340 alloy steel billet > crank might be totally indestructible. > > Now we can get a forged verses billet discussion going. :-))) > > On another note, there's something interesting to throw out there about > nodular iron cranks. Even though nodular iron *is* a form of cast > iron, what > is nodular iron, really? The receiver for the Browning Automatic Rifle in > the later half of WW2 was made from ArmaSteel. No matter what, they never > broke, even when repulsing 750 Chinese off of Pork Chop Hill (a > true story, > I met the man who did it) in Korea in the early summer of 1953. ArmaSteel > was developed by the Saginaw Division of General Motors to produce an > ordnance grade steel that was easier and quicker to machine than > the tough > alloy steels currently in use. ArmaSteel was a cast steel made with cast > iron mixed with scrap steel. The formula was patented by GM. The time to > machine a receiver for a BAR with traditional alloy steel dropped from 20 > hours to 2 hours with ArmaSteel, and the ArmaSteel was just as strong. I > wonder if an Olds nodular iron crank isn't actually an ArmaSteel > crank, cast > iron with steel thrown into the casting mix? A nodular iron crank > will make > a ring, similar but not quite as true, as a forged steel crank. Cast iron > cranks usually just go "thud." > > Anyone got any ideas? Discussion number 2. :-)))))) > > Milton Schick > 1964 442 Cutlass > [EMAIL PROTECTED] > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.405 / Virus Database: 268.10.8/415 - Release Date: 8/9/2006 > -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.405 / Virus Database: 268.11.6/427 - Release Date: 8/24/2006
