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Wanted to share this: a great bang for the buck imo:
Verified to be accurate. .8lbs total water and alternator aluminum pulleys
Oem water/alternator pulleys were twice the weight, 1.8lb's. So these are literally half the weight.
$89 shipped from asia on ebay took about 3 weeks very happy with these. These are supposed oem size will measure and follow up but quality and finish looks excellent.
Ebay aluminum water pump pulley
Last edited by F1TwoThousand; 07-23-2019 at 07:53 PM.
Nice, I've been thinking about getting these myself. Most seem to sell them as a set with crank pulley as well but definitely don't want to use that.
Looking forward to an update when you have installed them.
I've seen cheaper pulley sets crack(water pump pulleys). I went with Touge Factory water/alternator pulleys(made in the USA), as they are OEM sized. I use Fluidampr for the crank pulley. Toda Racing and other JDM brands are smaller/under driven sets.
Definitely dont reccomend using aluminum crank pulleys, i went with fluidampr myself. Taking out 1lb of accessory pulley weight can only help to lighten up the idle engine load. Every little bit counts. I had actually ordered a few months ago from this vendor and recieved the wrong parts. I recieved waterpump and alternator pulley for a 4g63 Evo. Funny enough the alternator pulley for that application was perfect for the S2K alternator. Vendor let me keep the mistaken pulley set and shipped a new set. When i got a new set the water pump pulley was perfect but as youll see below i measured the included alternator pulley to be 9% underdriven.
Long story short i ended up using the water pump pulley and the Evo 4g63 alluminum alternator pulley(was exact oem size and even ighter than the included s2k pulley (111g vs 76g)
Oem and aluminum waterpump pulley are basically same diameter. OEM steel pulley hub fits snugly on water pump hub. Aluminum pulley machined hub is .15mm too big which is ever so noticable and not a huge issue, i would think...
Last edited by F1TwoThousand; 07-24-2019 at 09:47 PM.
Has anyone who is supercharged and running a 6.5" crank pulley had to go for a smaller water pump pulley due to SC belt to water pump pulley collision?
I recently purchased the 4g63 pulley based on the information in this thread. While useful and extremely informative, it does not give the full story.
The inner barrel of the 4g63 is much deeper and does not allow the alternator nut to mount as far down the shaft thread of the alternator. You are lucky to get a 1/2 turn to full turn before torqueing.
I ruined the shaft on my alternator before realizing this. Even though the "oem sized" lightweight pulley is underdriven, I prefer the comfort of having the nut seated down as for on the alternator threads/shaft as possible.
The inner barrel of the 4g63 lightweight pulley is 17-18mm
The inner barrel of the s2k lightweight pulley is 11-12mm
On my OEM S2k alternator shaft, there are 9-10mm of threads. This is only the threads NOT the entire shaft.
From the base of the shaft, where the pulley seats, to the lowest portion of threads is 9-10mm.
That makes the base of the shaft to the tip of the treads 18-20mm
S2k lightweight pulley will leave you with 7-8mm of thread for the alternator nut to thread down
4g63 lightweight pulley will leave you with 1-2mm of thread for the alternator nut to thread down.
Forgive me on the approximations with measurements as my caliper digital screen is not currently working. The manual measurements work perfectly fine.
I hope this helps someone in the future as I wasted $40 on the 4g63 pulley, ruined the alternator shaft, and will now have to purchase another alternator or have this one rebuilt. Costly mistake on my part.
Godspeed
Last edited by 9KEVERYDAY; 01-13-2024 at 09:30 AM.
Reason: Correct math
07-23-2019, 07:51 PM
Ebay lightweight alternator/waterpump Pulley review
