WTB: 2000-2002 V8 LS Pulleys

mholhut

mholhut

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As the title says, just wondering if anyone has access to any pulleys off the first gen V8 LS. I have a friend who is going to machine me a series of aluminum and underdrive pulleys, beginning with the idler pulleys, working up to accessory pulleys and ending with the crank. I'm going to dyno the car after each series to see if there's a measureable gain before I go further.

Once he duplicates them, I'll be able to out-source the files to a company that would be able to produce them en-mass. I had a line on some from LLSOC, but that hasn't worked out. I'd take them off my own LS, but he says he'd need them for a while as he works on them in his spare time and wouldn't be able to get them back to me quickly.

Anyone got any leads for a future R&D project?
 
Mike,

You know I'm interested in this for sure. One question though, do the pulley's have the harmonic balancer on them?
 
Ken, I'm putting off the crank pulley for last. The LS uses a harmonic ballancer and there's always a risk of damaging the crank if you go with a solid pulley instead. The solution would be to piggy-back the ballancer onto the under-drive crank pulley. The engineering behind this has to be precise, so I'm going to leave the risky stuff to the end.

The easiest place to start would be to replace the idler pulleys. Since they just keep tension on the belt, reducing their weight would lighten the drain of power on the motor. This would be relatively cheap to do.

The next place to go would be accessories such as the water pump, alternator, and A/C unit. Lightening these would help to, but an added advantage would be to under-drive them to lighten the load more. The pulleys are actually larger than stock so they turn the accessories slower.

I have the engineer and the stock all lined up... just need something to replicate. The guy that is doing this for me is going to be starting his own milling operation, using a Bridgeport, lathe and eventually, a CNC machine.
 
Lightening these would help to, but an added advantage would be to under-drive them to lighten the load more. The pulleys are actually larger than stock so they turn the accessories slower.


Question, If the pulleys are larger dosen't that make them overdrive pulleys?
A smaller pulley would be an under drive pulley, right? I'm just confused I guess. :Bang
 
It's a misnomer. Underdriving a pulley makes it larger, but it's turning less frequently.... therefor under-driving it. If the pulley was smaller than stock, you'd be over-driving it since it would be turning faster. The only pulley I'd consider over-driving, would be the alternator; just to make sure the battery stays charged. Slightly over-driving it would just bring it back to stock if the other pulleys were under-driven.
 
mholhut said:
It's a misnomer. Underdriving a pulley makes it larger, but it's turning less frequently.... therefor under-driving it. If the pulley was smaller than stock, you'd be over-driving it since it would be turning faster. The only pulley I'd consider over-driving, would be the alternator; just to make sure the battery stays charged. Slightly over-driving it would just bring it back to stock if the other pulleys were under-driven.
Click to expand...

Thankx. I almost hurt myself trying to figure it out.
 
mholhut said:
It's a misnomer. Underdriving a pulley makes it larger, but it's turning less frequently.... therefor under-driving it. If the pulley was smaller than stock, you'd be over-driving it since it would be turning faster. The only pulley I'd consider over-driving, would be the alternator; just to make sure the battery stays charged. Slightly over-driving it would just bring it back to stock if the other pulleys were under-driven.
Click to expand...
Under/over...sheesh! :Bang
 
Sounds legit as a machine shop owner, I would agree that this process willnt take to long but you might want to have then checked on a balancing machine before install ,+-.0005 to much off of one side could it up throwing the whole motor out. Unless he has a CNC lathe that you can actually guarntee a true piece, sometimes is the only way I would trust it. Thats just my thoughts on machining these pieces. I personally dont own a CNC so I dont get into this type of work. I can make them but I would have them balanced.
Good luck and I would also be interested in a set once tested!

-Scott-
 
Lightening the Idler and Tensioner pullies is not going to make any noticeable difference. As long as the bearings are good and not binding, they don't create enough drag to be an issue.

The horsepower gain (or recovery) from underdrive pullies is mostly from the crank pulley/harmonic balancer. The use of a smaller and lighter pulley allows the crank to spin more freely by reducing the mass of it. I would not recomend eliminating the balancer or using a piggy-back setup, they will cause more problems (such as excessive wear or catostrophic failure) than they are worth. That's why FRPP and Steeda use a pulley-balancer just like stock, only smaller and lighter.

Yes, a smaller crank pulley will cause everything else to spin faster. That's where oversized acc. pulleys come in. They slow everything back down (or even slower than original) to reduce the drag caused by the accessories. Usually, the only pullies that will be replaced are the crank, the water pump, and the alt. I'm sure that the p/s pulley could be replaced, but overdriving it isn't really going to cause any problems. The a/c pulley isn't changed for a couple of reasons. First, because of the internal clutches it would be more trouble than it's worth. Second, underdriving it will make it work harder and longer to do the same job as before; it will be engaged more than it would be otherwise, causing more drag and a loss in fuel economy (taking a step backwards).

My suggestion is to work on the crank pulley and harmonic balancer issue first. The size of it is going to determine what size the rest of the pullies need to be.
 
Dead President said:
np
Click to expand...


Here was there long reply! HAHA

"Sorry, we do not offer anything for the 3.9L. It is different than the 3.8 and 4.6 motors. "

Next idea or company!

-Scott-
 
GrayGhost1 said:
Salvage yard. Get one and throw in a CAD file and pop them out by the hundreds!
Click to expand...

Well MR. Connections who do I email for those items? :N

-Scott-
 
I've been to many salvage yards when I was helping out a buddy of mine do a cobra motor swap into his GT. I can almost guarantee they will not sell just the pulleys alone because if a buyer comes across needing that complete motor they will be SOL. Plus, who would want to buy an uncomplete longblock. I wouldn't, mainly because I knew parts were being sold off of it and other parts could be missing. Atleast that's how I look at it, g/l finding a set
 
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