Thread: Crank Pulley Separation

Recently, I swapped my SR20 USDM for a JDM due to rod knock.
The swap went fine with the help of alot of the Maryland Forum Crew and one Texas dude named Tekkie that was visiting the area . After successfully starting the car completing the swap, I couldnt set the timing b/c the timing light at the shop was broken. So I just set the dizzy in the middle of the slots (about 13-14deg) and drove the car home.

Well once home, I tried to set the timing. Using Datascan, set the car in timing mode. Connected the Timing light and was shocked to not see any timing ticks...
Searching for the Timing ticks, I found them waaaaay left, super advanced, 80+deg. Knowing that was impossible, I moved the dizzy around far left & right. The idle was changing but the timing ticks stayed way left. Suspect: Crank Pulley Separation!! Tested everything else to validate spec condition: TPS, MAF & ground, Dizzy, etc. Nothing corrected the problem.

So, we swapped the Crank Pulley. And Voila ! ! The old pulley was starting to separate on one side.. Problem fixed.
Thats the 2nd bad Crank Pulley found in a month, here in Maryland. The other one had tick marks going round & round (complete separation).

Moral: If your Timing tick marks are waaaay off from the timing pointer OR tick marks spinning round & round:
Its probably your Crank Pulley beginning or completely separating.

Wow didn't think that was possible, that sucks and something I'll keep in mind.

I have UR crank pulley, so hopefully they are one piece, but never know...

Not sure about aftermarket pulleys. This one was a OEM pulley.
During the swap, we pulled the valve cover to check everything. Turned the crank to TDC and the sprocket pins were in the correct position & 20 links between them. The timing chain was tight and looked in excellent condition.

Before changing the Crank Pulley, we checked everything again. Same results: Crank Pulley set at 0deg/TDC with correct pin location/20 links..
Our conclusion was: Under engine torq, the crank pulley changed position and thus moving way left of the pointer.

Very common with harmonic balancer pullies. It happend to my pathfinder, g20 and my bro's 3000gt.

There was just a thread on g20.net where it seperated and the outter ring went flying off down the road!

One piece pullies won't have this problem as there isn't any rubber to deteriorate. But there must be some stress on these things if they are breaking right? Makes you question if you really should be putting a solid piece on at all?

on a solid pulley this won't happen, these engines are balanced very well from the factory, 8cw crank, and i have yet to see a premature engine failure with ur pulleys. the reason the balancer gets wrecked is not because of excess vibrations but because of dry rot on the rubber combined with small vibrations the dampner sees will rip the rubber apart.

Do you have some pics of how the stock pulley looks now?



^You have a point, but I will still be running UR pulleys on my car. I like the way totaled200ser put it.

I'm not totally against UR pullies. I had one on my KA for many miles with no problems. As far as the SR being 8cw crank that is not the whole truth. Not all use the 8cw crank. I do believe the RR use 4. I'm not positive but think they do.

rob you are right but his car is a nx- that is why i made that statement, sorry if i was confusing, lol

High ports and Lowports use 8cw, RR's and VE's use 4cw.

You will hear a lot of people say to never use crank pulleys on RR's and VE's. To be safe I wouldn't either, but quiet a bit of people also have used Pulleys on those motors without any problems...

Okay, Ive seen a few crank pulleys but not really noticed the differences from a RR or VE. What actually is a 8cw crank?

I considered a UR pulley but couldnt find one..