Does this custom pulley rib spacing appear safe?
05-18-2015, 06:42 PM
#1
Does this custom pulley rib spacing appear safe? I had a problem with overcharging the stock alternator with the stock pulley last year while tuning VE in the upper RPM's, so I chose to go through AEICNC to cut a custom 2.75" pulley out of billet steel. I don't recall what the exact price was, but it was north of $100.
I have the custom pulley installed and within a couple of weeks I noticed my serpentine belt was starting to shred on the outer edge, and upon closer inspection the belt had slid over the outside edge of the ATI crank pulley by one rib. Long story short, the rib spacing on the new pulley was too far from the alternator.
After taking off the custom pulley and comparing it to the steel pulley I had been using successfully for years, this is what we see (custom on the left, steel on the right):
So I sent the stock pulley off my spare truck alternator with the custom pulley back, requested he safely minimize the mass, fix the rib spacing by comparing it to the sample pulley, and add a taller outside rib wall.
Below is what I received today, in addition to a 1/8" washer and my old pulley. The custom pulley is 141g heavier, and the outer lip diameters are 2.74"/2.80" compared to 2.28"/2.4" on the used pulley. I tried to get the camera level with the center ribs, but does it appear this spacing is close enough to not cause any problems? The custom pulley is on the right.
If it's not close enough to be reliable under all street/autocross/HPDE conditions, then I'm going to request to return it for a complete refund.
I have the custom pulley installed and within a couple of weeks I noticed my serpentine belt was starting to shred on the outer edge, and upon closer inspection the belt had slid over the outside edge of the ATI crank pulley by one rib. Long story short, the rib spacing on the new pulley was too far from the alternator.
After taking off the custom pulley and comparing it to the steel pulley I had been using successfully for years, this is what we see (custom on the left, steel on the right):
So I sent the stock pulley off my spare truck alternator with the custom pulley back, requested he safely minimize the mass, fix the rib spacing by comparing it to the sample pulley, and add a taller outside rib wall.
Below is what I received today, in addition to a 1/8" washer and my old pulley. The custom pulley is 141g heavier, and the outer lip diameters are 2.74"/2.80" compared to 2.28"/2.4" on the used pulley. I tried to get the camera level with the center ribs, but does it appear this spacing is close enough to not cause any problems? The custom pulley is on the right.
If it's not close enough to be reliable under all street/autocross/HPDE conditions, then I'm going to request to return it for a complete refund.
05-20-2015, 03:27 PM
#3
With the belt sitting in the grooves it was fine, a little less material on the back of the pulley. The owner said he wasn't having as good of luck using his equipment on steel when it was designed for aluminum. Without me asking he offered a full refund including shipping, and I can keep the pulley just in case I can make it work. I took him up on the offer and just ordered a March 208 pulley also just in case it doesn't.