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Old 12-21-2015, 12:36 PM   #1
Mrturner1
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Aftermarket crank pulley smaller than OE?

I got a couple pulleys to dress up the front of the engine a little, and the crank pulley is smaller than the original. Is this going to cause a problem?
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Old 12-21-2015, 07:07 PM   #2
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Re: Aftermarket crank pulley smaller than OE?

Anybody?
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Old 12-21-2015, 07:43 PM   #3
midniteblues
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Re: Aftermarket crank pulley smaller than OE?

They should work fine as long as all the grooves line up with the old pulleys.

A smaller diameter crank pulley might speed up the other pulleys depending on there size. But you'll never notice the differnce.
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Old 12-21-2015, 07:44 PM   #4
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Re: Aftermarket crank pulley smaller than OE?

Your accessories will run slower than with the stock crankshaft pulley. The rule is larger accessory puller the slower the accessory will run, conversely the smaller the crankshaft pulley the slower. You can do the math if you want, it is a matter of ratios between the drive pulley and driven pulleys.
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Old 12-21-2015, 07:47 PM   #5
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Re: Aftermarket crank pulley smaller than OE?

I gave wrong advice........................
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Last edited by hamjet; 12-21-2015 at 09:48 PM.
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Old 12-21-2015, 09:33 PM   #6
swamp rat
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Re: Aftermarket crank pulley smaller than OE?

Nope, a smaller pulley equals less surface on the diameter of the pulley, less surface means a slower belt and accesorys turn slower
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Old 12-21-2015, 09:46 PM   #7
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Re: Aftermarket crank pulley smaller than OE?

Quote:
Originally Posted by swamp rat View Post
Nope, a smaller pulley equals less surface on the diameter of the pulley, less surface means a slower belt and accesorys turn slower
You are correct, where is my brain tonite....
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Old 12-21-2015, 09:46 PM   #8
trac209
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Re: Aftermarket crank pulley smaller than OE?

Quote:
Originally Posted by swamp rat View Post
Nope, a smaller pulley equals less surface on the diameter of the pulley, less surface means a slower belt and accesorys turn slower
reread that you're correct,but only if you're talking main pulley diameter. If the accessories pulleys are larger it slows them down
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Old 12-22-2015, 08:42 AM   #9
midniteblues
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Re: Aftermarket crank pulley smaller than OE?

Thinkin an typing don't work sometimes.
it will slow it down the belt.
But like I said you won't notice it.
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Old 12-22-2015, 08:49 AM   #10
hamjet
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Re: Aftermarket crank pulley smaller than OE?

Worst case is if the RPMs are low at idle and some accesories like heater fan or head lites on you might see the alternator light flicker if you have idiat lite or the needle might show discharge on a gauge..
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