Author Topic: Crankshaft interchange question???  (Read 2898 times)

Offline nosrettaw

  • Jr. Member
  • **
  • Posts: 95
  • 1974 'Cuda
Crankshaft interchange question???
« on: October 17, 2002 - 04:10:30 PM »
 ???   I need a crankshaft for my 440 and the guy at the parts store did nothing but confuse me. My question was that I have a cast crank now with the external weight on the balancer, can I go to the steel crank and change balancers? I am tring to build a blower motor and they recommend a steel crank. I would have just used this cast one but then it requires a speacial made pully for that balancer and plus they recommend a standard grind shaft mine is 10/10. So I figured I would ask you guys because most of those parts guys are Chevy guys and most of us know if it is not in the book they don't know...So if someone can tell me please let me know..
Thanks Steve
Fried Fish Smells Like Burning Rubber !!




Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re:Crankshaft interchange question???
« Reply #1 on: October 18, 2002 - 01:11:36 PM »
The steel crank is a drop in  ;)

Challenger - You`ll wish You Hadn`t

Offline nosrettaw

  • Jr. Member
  • **
  • Posts: 95
  • 1974 'Cuda
Re:Crankshaft interchange question???
« Reply #2 on: October 18, 2002 - 03:44:03 PM »
 ;D  that is what I thought and that is what my Dad told me. He is a huge Mopar nut. But the guy at the parts store confused me. That would be the last thing I wanted to do is spend $10,000 on a viberating blown 440. Thanks Again Fella's

If it is not a 350 chevy don't go to Advanced Auto Parts.... :P ;D
Fried Fish Smells Like Burning Rubber !!

Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re:Crankshaft interchange question???
« Reply #3 on: October 19, 2002 - 06:27:50 AM »
 What the parts guy was concerned about is the weight of the rod/piston assemblies being the same as the cranks are balanced for a specific weight but the non hp 440s use the same rod / pistons & if you are going to supercharge the engine you will need to replace the pistons & use a stronger & lower compression piston which will require having the rotating assembly balanced anyway  ;)

Challenger - You`ll wish You Hadn`t

Offline nosrettaw

  • Jr. Member
  • **
  • Posts: 95
  • 1974 'Cuda
Re:Crankshaft interchange question???
« Reply #4 on: October 22, 2002 - 06:09:03 AM »
 :D Yes I know, I have got a new set of Aries that are 7.4 to 1 Ratio. they say they are good.? A guy my Dad works with has just supercharged his '71 Cuda and those are the same pistons he bought. $585.00 bucks (ouch!!). And he is trying to sell me a set of Six Pack Rods that he has. He said they are heavier and that I will need them. But can I even use them? He just told me that you would have to balance them with the piston's anyway. But will that mess things up? I don't think he know's exactly what I have got for a engine / rotating assembly, he don't have them in his Engine, he bought the fancy H-Beam rods for his. If I used them would they still need the Six Pack balancer?? What do I got going on?? I want to use a steel crank because they recommend it, But what do I do about the rods? Can I use the 6-Pack rods? Or will the stock rods do fine? It will be a driver so the boost will not be that high. For a daily driver they recommend 5psi boost. Can they swing that?? ??? ;D

Thanks  Steve
Fried Fish Smells Like Burning Rubber !!

Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re:Crankshaft interchange question???
« Reply #5 on: October 22, 2002 - 12:40:02 PM »
 Good rods are a good idea , I used six pack rods & had the rotating assy balanced by lightening the rod & adding metal to the crank & then you can use the neutral balance damper, if can afford them I would use the Eagle rods  though  

Challenger - You`ll wish You Hadn`t

Offline nosrettaw

  • Jr. Member
  • **
  • Posts: 95
  • 1974 'Cuda
Re:Crankshaft interchange question???
« Reply #6 on: October 23, 2002 - 02:16:11 AM »
Thanks You are the Man !!! ;D
Fried Fish Smells Like Burning Rubber !!

Offline BIG MIKE

  • Sr. Member
  • ****
  • Posts: 1270
Re:Crankshaft interchange question???
« Reply #7 on: October 23, 2002 - 03:24:22 AM »
don't they balance separate the rods pistons and crank?
i though they took the lightest  then removed metal till all is the same ???

Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re:Crankshaft interchange question???
« Reply #8 on: October 23, 2002 - 04:13:18 AM »
 You are correct, you take the lightest of each component & match the weights of each to the lightest , that gives you a consistant "bob" weight, which is the total weight of the piston , rod brgs & rings,  then the crank is balanced for that "bob" weight , also the rods are balanced at each end not toal weight as the weight 7" from the crank has more effect than weight attached to the crank

Challenger - You`ll wish You Hadn`t