Is there anyone that makes a larger crank pulley for the SOHC 4.6L?

Gearbanger 101

Straight Outta Locash
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Aug 10, 2002
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I was curious, since my supercharged set up will be running between 9psi or so. To do that with my Eaton, it’s going to require about a 2.5” pulley. I was thinking that rather than go with the small blower pulley to spin the blower harder (that will most definitely result some in belt slippage), wouldn’t it be more practical for me to go with a larger crank pulley, that would spin the system faster and allow me to use a larger diameter pulley for the blower? Doing this would still allow for the proper ratio in order to make the required boost, while increasing the available surface area in which to contact the belt face and would lessen slippage?

Not only that, but it would also spin the water pump faster at low RPM, to improve cooling in the city. True the Alternator would spin faster at high RPM as well, but it’s easy to just swap out to a large pulley to bring things down to safe speeds again.

I figure doing it this would have to be cheaper than converting to an 8-rib set up to achieve the same results?

Any opinions? :shrug:

*EDIT*
….sorry, tried to post this in the “Power Adder” section, but this site is going banana’s today and it kept rejecting the thread?
 
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I'm not sure on the crank pulley, but you could try to pick up a used set of underdrive pulleys cheap and just use the waterpump and alternator pulley to slow them back down.

Personally, I'm using the SFI approved dampner from Jegs with the underdrive alt & w/p pulley's with no problem - just had to get a 96.5" belt to fit. I wanted to use a higher quality crank pulley on the new motor so I dumped the u/d crank pulley.

Jay
 
GT2000JAY said:
I'm not sure on the crank pulley, but you could try to pick up a used set of underdrive pulleys cheap and just use the waterpump and alternator pulley to slow them back down.

Personally, I'm using the SFI approved dampner from Jegs with the underdrive alt & w/p pulley's with no problem - just had to get a 96.5" belt to fit. I wanted to use a higher quality crank pulley on the new motor so I dumped the u/d crank pulley.

Jay
Yeah, but keep in mind though, I'm blown. Under drive pulleys consist of a small crank, with large alt and water pump. Going with under drive pulleys will slow the blower down not speed it up, which does the opposite of what I want. I need to go with a larger crank pulley, in order to increase the belt speed. Only then would I need to slow down the water pump and alternator.

Do ya kinda see what I'm saying? :shrug:
 
jstreet0204 said:
Would a lightning pulley work or is it 8 rib. I know kenne bell sells them for the lightning.
http://www.kennebell.net/accessories/LightningCrankPulley/CrankPulley.htm
That's a good question; I'll have to look into that. Stepping up from the stock 6.8” to the 7.5” might be what I’m looking for? Another problem that arises is will doing so create any unwanted crankshaft harmonics. I realize that the modular engines are internally balanced and that the stock crank pulley is a dampener, not a balancer, but regardless do the 5.4 and 4.6 use the same dampener?
 
Some of the passenger car 4.6 SOHC's might have a larger crank pulley. Lincoln might have had it on the town car to increase accessory speed for A/C and alt. In some of those cars, performance is sacrificed for comfort
 
Gearbanger 101 said:
Yeah, but keep in mind though, I'm blown. Under drive pulleys consist of a small crank, with large alt and water pump. Going with under drive pulleys will slow the blower down not speed it up, which does the opposite of what I want. I need to go with a larger crank pulley, in order to increase the belt speed. Only then would I need to slow down the water pump and alternator.

Do ya kinda see what I'm saying? :shrug:

Yep, saw what you were saying in the original post. I was recommending using an oversized crank pulley with the oversized alt & w/p pulleys from an underdrive kit. This would help to keep you from overdriving the alternator and water pump.

GT2000JAY said:
I'm not sure on the crank pulley, but you could try to pick up a used set of underdrive pulleys cheap and just use the waterpump and alternator pulley to slow them back down.

Jay
 
The 5.4 balancer is slightly bigger than the stock sohc balancer..It also allows you to go 8 rib for better belt "traction"..Kenne bell sell a 7.5 and a 8.5 balancer kit BUT its for a 8 rib setup and you have to use their balancer (its machined for their pullies).

But The other companies mentioned have over sized bakancers also..
 
What about a piggy back pulley that bolts directly to the stock dampner? :shrug:, I don't want to sound like a total cheap skate about this, but I don't want to drop a pile of money on a custom dampner, if I can achieve the same result with just an add on pulley.