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3U crank??

March 12 2012 at 12:36 PM
  (Login 427kiwi)
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Can anyone tell me what a 3U crankshaft is? I have aquired one that seems in good order and is std/std. It may have come out of a marine 427?
Thanks,
Nigel.

1965 427 Cobra Replica.
1963 1/2 Q code XL Galaxie 4 speed project.
FE thunder downunder!

 
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HALowe
(Login Halowe)
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According to what I'm finding,...

March 12 2012, 12:42 PM 

it could either be a 391 FT crank, a '73 and later 390 truck crank, OR a 427 industrial crank.

Edit: and, it could be a 427 marine crank or a 1968 427 crank.

 
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(Login Halowe)
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More info here...

March 12 2012, 12:48 PM 


 
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(Login 427kiwi)
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3U ?

March 12 2012, 1:52 PM 

Is the 3U crank cast or forged steel?
Thanks,
Nigel.

1965 427 Cobra Replica.
1963 1/2 Q code XL Galaxie 4 speed project.
FE thunder downunder!

 
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Beoweolf
(Login beoweolf)
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there is a visually unique way to tell forged cranks.

March 12 2012, 3:39 PM 

 why not check it your self....

  1. Look at the counterweights on the crank. A large parting line with grinding marks on it is indicative of a forged steel crank. That is because it was forged and bent into shape. The cast iron crank will always have a very thin straight line on the counterweights. This shows where the crankshaft was separated from the mold. The thin line is the parting line between mold halves.

  2. Look closely at the surface of the crank. A forged crank has a relatively smooth surface, while a cast-iron crank has a pock-marked appearance and a rough surface.

By the way  FORDificatiion.com has has a tech page with info about FE cranks ... might be educational?

1U '68-'69 428 c.i.d. Police Interceptor & Cobra Jet
1UA '69-'70 428 c.i.d. Police Interceptor & Super Cobra Jet
1UB '69-'70 428 c.i.d. Police Interceptor & Cobra Jet
2T '68-'76 330MD, 360 c.i.d.  
'64-'78 330HD, 361 c.i.d. Heavy Duty Truck, 1 3/8" Pulley Snout Diameter, Forged Steel
2TA '64-'78 330HD, 361 c.i.d. Heavy Duty Truck, 1 3/8" Pulley Snout Diameter, Forged Steel
'68-'76 330MD, 360 c.i.d.  
2TAB '64-'78 330HD, 361 c.i.d. Heavy Duty Truck, 1 3/8" Pulley Snout Diameter, Forged Steel
2U '66-'73 390 c.i.d. Car & Truck Use
'64-'78 391 c.i.d. Heavy Duty Truck, 1 3/8" Pulley Snout Diameter, Forged Steel
2UA '73-'76 390 c.i.d. Truck
3U '73-'76 390 c.i.d. Truck
'64-'78 391 c.i.d. Heavy Duty Truck, 1 3/8" Pulley Snout Diameter, Forged Steel


http://www.fordification.com/tech/castingnumbers-FEcrank.htm
... Labor Omnia Vincit ..


 
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(Login twistedcrankcammer)
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Forged Steel Cranks

March 12 2012, 10:51 PM 

X2 on what Beoweolf said! That's why my signature is TwistedCrankCammer, all Cammers had forged steel cranks and the steel cranks were all twisted back in the day! Extremely easy to spot the difference between steel and cast this way!

Roger

 
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(Login DYNO427)
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I have a 3U.....

March 12 2012, 4:00 PM 

that's from a marine 427 [1967] and it is the reverse rotation crank----that has been giving me all the oil leaks at the rear main seal area! Most everyone here who is familiar with my oil leak problems,and have convinced me to replace the crank with one that is "normal" rotation.[car type] Oil seal "hash marks" face the wrong direction for use in a car engine---they promote oil seal leakage! We'll see soon! Repairs are about to take place! Dyno 427

 
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(Login RM428)
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Re: I have a 3U.....

March 12 2012, 9:04 PM 

Every 3U crank that I have ever seen has been cast iron.

428 powered Fairmont drag car, Best ET:10.03@132.11MPH, best 60 ft: 1.29
59 Meteor 2 dr. sedan 332, Ford O Matic
74 F350 ramp truck 390 4speed

 
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Eddie
(Login a70eliminator)
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Re: I have a 3U.....

March 13 2012, 2:15 PM 

I've never actually seen one but read about the steel crank with a $ cast in next to the part number, NASCAR crank maybe?

 
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