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Cast crank pulley versus forged crank pulley

Posted By: dweller

Cast crank pulley versus forged crank pulley - 01/24/14 06:07 AM

Just wondering if anyone can say for sure whether the depth of the crank pulley differs between a mid 70s cast crank 440 and a forged crank 440? I pulled a 440 out of a W200 that was a cast crank motor and rebuilt it with a forged crank and the matching forged crank balancer. My research indicated that I would be able to reuse the four pulley crank unit from the original motor despite having swapped the crank. Now upon reassembly, it looks like the accessory pulleys are off by a small amount, and I'm not sure whether its due to bracket misalignment or a different pulley depth. Any help and/or pictures would be appreciated.
Posted By: Kern Dog

Re: Cast crank pulley versus forged crank pulley - 01/24/14 06:12 AM

Lots of stuff changed in the 70s.
The switch from forged to cast cranks, MORE engines equipped with A/C, smog pumps on some cars, etc.
I have a bunch of pullies here from cast crank engines. I have used them on both forged and cast crank engines and had some that fit and aligned better than others. I don't think that a 4 groove pulley is that much different from a cast to a forged application.
Posted By: m88mark

Re: Cast crank pulley versus forged crank pulley - 01/24/14 06:38 AM

Call Bouchillin, Helped me on my pulleys, spacers also available. Mark
Posted By: Commando1

Re: Cast crank pulley versus forged crank pulley - 01/24/14 03:31 PM

Quote:

My research indicated that I would be able to reuse the four pulley crank unit from the original motor despite having swapped the crank. Now upon reassembly, it looks like the accessory pulleys are off by a small amount, and I'm not sure whether its due to bracket misalignment or a different pulley depth.


I can say with some confidence it's due to a pulley or bracket reinstalled incorrectly.
I have done mix 'n match on these parts between steel and forged crak BB's many times and the spacing is the same and everything will line up.
That is, if everything is swapped as one set.

I will also ashamedly admit I once reversed the water pump pulley and....
well, you know the rest.

Cast crank engine now with steel crank:
All brackets and pulleys from the cast crank engine.
Posted By: dweller

Re: Cast crank pulley versus forged crank pulley - 01/25/14 06:05 AM

Thanks Commando1. The more I look at it, the more I realize that the OEM brackets are just not that "dialed in"! They're pretty close, but I'm just going to have to use some spacers here and there to get it perfect. I have the same crank pulley that you show in you picture. Thanks for the responses everyone.
Posted By: Commando1

Re: Cast crank pulley versus forged crank pulley - 01/25/14 03:50 PM

Yes, they are ugly as hell and will never win you show points but you can't beat the mid-seventies brackets. They are as rigid and secure as a girder bridge and they are also cheap and plentiful. Plus you get a hefty and super reliable 100A alternator out of it.
Ain't sexy but....
Posted By: NachoRT74

Re: Cast crank pulley versus forged crank pulley - 01/25/14 06:14 PM

I stroked my 400 ( cast assembly ) with 440 forged crank and correct dampener to forged crank with offset hole ( 70s setup ) to reuse my original stock pulley. Everything lined up perfect.
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