Difference beteen 89 crank and 94-95?

C_More

Registered User
The reason I'm asking this is because recently I purchase a rebuilt motor and my 89 BHJ balancer won't fit onto the crank.The crank shaft seems to be to big and the balancer goes on tell just past the timing covers front seal,then stops and wont go any further.I tested to see if the balancer would fit my 91 motor and it slipped right on.This rules out the balancer so could I have a 94-95 crank or possibly a 3.8 N/A crank?I'm interseted on what you guys think so please leave me any advise because I need to contact to motor company but want to be well informed before I do so.

Thanks,
Chris
 
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No difference in cranks. Did you loose the installation instructions for the BHJ??? Did you measure the crank and dampner to make sure there was only .001 interferance??? Some BHJ dampners need to be honed to fit the crank.
 
I wonder if there is a difference between the Duracast and forged cranks. Some 89's came with the Duracast cranks.

-Rod
 
racecougar said:
I wonder if there is a difference between the Duracast and forged cranks. Some 89's came with the Duracast cranks.

-Rod


yes i believe there is... the duracast i believe are externally balanced.. and the forged are internally balanced. thats why duracast cranks have those special 5 speed flywheels that are externally balanced.
 
Thanks for the feedback I will be calling the motor company tommarow and ask them if its a duracast or forged crank this my give me better answers,I still dont want to rule out a N/A 3.8 crank though. Didn't the N/A 3.8 come with the cast crank?I'm just trying to find out why the crank is too large.So could I have a N/A 3.8 crank?

Chris
 
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The 3.8L N/A did come with a cast crank. IIRC, a 3.8L N/A crank would have to be machined to be installed into a SC block. I believe that was intentionally done by Ford so that a N/A crank wouldn't accidentally be installed in a SC engine.

Since you have a 89, I'd bet that the issue is that you have a Duracast crank.

-Rod
 
I dont think there are any duracast around anymore. Most failed while the SC was under warrenty and replaced with forged shortblocks. In my many years here on SCCOA i never even seen a duracast crank. You are not special stop thinking there is something wrong with the crank honing a BHJ dampner to fit is normal.
 
Special?When the balancer fits my 91 motor just fine but won't fit the 89 rebuilt motor this raises a red flag,I would refer it as being curious.When you spend lots of $ and countless hours on this car it would be stupid not to ask questions.I have completed 2 motor swaps and never ran into this problem so I hope you can realize why this threw me.


Thanks for the info on the cranks.Honing the balancer seems to be the only solution.


Chris
 
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C_More said:
The reason I'm asking this is because recently I purchase a rebuilt motor and my 89 BHJ balancer won't fit onto the crank.The crank shaft seems to be to big and the balancer goes on tell just past the timing covers front seal,then stops and wont go any further.I tested to see if the balancer would fit my 91 motor and it slipped right on.This rules out the balancer so could I have a 94-95 crank or possibly a 3.8 N/A crank?I'm interseted on what you guys think so please leave me any advise because I need to contact to motor company but want to be well informed before I do so.

Thanks,
Chris
A BHJ balancer comes with the hole a little small and either needs to be honed to match a certain range of the size of the crank (or vise-versa). I don't remember the specs, but you can get them from BHJ. Also, the balancers are different because of the crank sensing ring. But for your situation, I don't think that will matter.

Of course, I would still try to verify if you have a duracast crank before proceeding.
 
If the motor is not in the car, then pull the pan and check. Otherwise I don't know of any way to make sure. You'd hate to hone out the balancer and then find out that the crank is wrong. Then you'd be buying a new balancer as well.
 
Forged crank has a huge over 1'' forging line that you can see. Cast cranks have a very thin casting line. If im wrong someone please correct me, its been awhile since i saw a cast 3.8 crank. You can also do a search this issue has been covered a million times.
 
BKB said:
Forged crank has a huge over 1'' forging line that you can see. Cast cranks have a very thin casting line. If im wrong someone please correct me, its been awhile since i saw a cast 3.8 crank. You can also do a search this issue has been covered a million times.

The forging line isn't quite that large, but that is right. Cast crank = thin line, forged crank = thick line.

-Rod
 
C_More said:
getmsg
[/IMG] Let me know if you can tell from this picture!
Link doesn't work for me.
 
Kurt K said:
Link doesn't work for me.
I tried to upload the picture but I'm having problems because of the size!When I make it 200 KB then its to small to see the crank clearly!I sent you an email of the picture!

Chris
 
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C_More said:
I tried to upload the picture but I'm having problems because of the size!When I make it 200 KB then its to small to see the crank clearly!I sent you an email of the picture!

Chris

Here you go.
 

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  • crank_pic.jpg
    crank_pic.jpg
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I can't spot a forging/casting line in that picture. Can you rotate the crank until the line is showing, and just take a picture of the line?

-Rod
 
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