Forged crank question..............
Thread Starter
Le Mans Master
Joined: Sep 2001
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From: State of Confusion.
Forged crank question..............
Why does a forged crank for an LS1/LS6 motor cost $2k+, when you can buy a small block Chevy (forged in your choice of strokes) for around $500. Aren't they made the same way. I mean, a crank for a Big block Chevy is probably in the 700-800 buck range, and that's a bunch more iron than our LSx stuff. I could only think that they sell a bunch more of the standard small block cranks, so they would make their money in volume, but if prices were cheaper on our cranks I'd bet that there would be a whole bunch more strokers out there. Just food for thought. Thanks for listening.
Le Mans Master
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Re: Forged crank question.............. (LuvmyC5)
Well there is a lot more to crankshafts than just saying it is "forged". The biggest difference is the type of steel that is used when machining it. The best would be 4340, then followed by 4130, and then there are some lower quality steels as well.
Also, crankshafts can have all sorts of machining done to them to make them lighter, stronger and cause less resistance as they swoop through the oil in the pan.
A $500 SBC "Forged" crankshaft is not on the same level as the $2000+ 4340 Lunati or Callies LS1 crankshafts out there. Mind you, SBC and BBS crankshafts usually are less expensive than LS1s, but that is mainly due to the fact that they have sold way more of those crankshafts and have less R&D dollars to recoop. I am sure over time LS1 crankshaft prices will keep going down and down.
Just make sure you are comparing apples to apples on all aspects of a crankshaft when shopping for one.
Also, crankshafts can have all sorts of machining done to them to make them lighter, stronger and cause less resistance as they swoop through the oil in the pan.
A $500 SBC "Forged" crankshaft is not on the same level as the $2000+ 4340 Lunati or Callies LS1 crankshafts out there. Mind you, SBC and BBS crankshafts usually are less expensive than LS1s, but that is mainly due to the fact that they have sold way more of those crankshafts and have less R&D dollars to recoop. I am sure over time LS1 crankshaft prices will keep going down and down.
Just make sure you are comparing apples to apples on all aspects of a crankshaft when shopping for one.
Thread Starter
Le Mans Master
Joined: Sep 2001
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From: State of Confusion.
Re: Forged crank question.............. (MattG)
Thanks Matt. I was just wondering about this, as about 10 years ago, I bought a 4340 Crower crank to make a 540 cube BBC, and the crank was $750. It was knife-edged, nitirded, balanced, and pretty big. Granted, like I said, it was about 10 years ago, and prices have gone up, but it just shocks me. Maybe I should get out of the stone-age. I forgot about R&D costs too, which probably makes up a pretty good size chunk of the cost.
[Modified by LuvmyC5, 11:43 AM 6/3/2003]
[Modified by LuvmyC5, 11:43 AM 6/3/2003]
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From: Austin Tx
Re: Forged crank question.............. (MattG)
There are several kinds of forged cranks, Single forging, double forging, and billet.
Once there is sufficient demand (which there is for SBCs) single or double forged dies are constructed and then cranks can be machined at (ahem) reasonable costs. The difference between single and double forgins in the number of times the forging block is struck and whether the carnk is rotated between strikes. Choice of steels 4130 and 4340 and some others.
Prior to the point where it is cost effective to make a forging die, a big block of forged steel is machined down to specs. This wastes a lot of expensive steel, tooling, and is basically hard--leading to being expensive. A carnk for a Ferrari F355 is machined out of billet (4340) and will run upwards of $4000!!!
Once there is sufficient demand (which there is for SBCs) single or double forged dies are constructed and then cranks can be machined at (ahem) reasonable costs. The difference between single and double forgins in the number of times the forging block is struck and whether the carnk is rotated between strikes. Choice of steels 4130 and 4340 and some others.
Prior to the point where it is cost effective to make a forging die, a big block of forged steel is machined down to specs. This wastes a lot of expensive steel, tooling, and is basically hard--leading to being expensive. A carnk for a Ferrari F355 is machined out of billet (4340) and will run upwards of $4000!!!
Thread Starter
Le Mans Master
Joined: Sep 2001
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From: State of Confusion.
Re: Forged crank question.............. (Mitch Alsup)
Thanks for the info, but a $4k Ferrari cranks sounds like a bargain when I read in Motor Trend (or Road and Track) that this gentleman had just bought an Enzo Ferrari paid $24k for brake rotors (carbon fiber), and oil is $60 a quart (it requires 12 of them). I was amazed because him and his son raced it on a track. I guess if you can afford the car, $24k for rotors isn't that bad. :eek:
