Nissan 300ZX Overdrive Water Pump Pulley Comparison

Full disclosure:
I along with several other vendors sell a competing product the HI Pulley
The HI Pulley is made in the USA from T6061 aluminum
The HI Pulley has had 2 design versions, both have the correct belt offset.
I do not manufacture, produce or otherwise "make" it.

AMS has stated that their pulley is directly based on the PEX Pulley from Australia
AMS (or their hangers on) have claimed that thousands of their pulley have been sold.
AMS has repeatedly claimed that their product has no design issues and attacked me for stating that that it does.

I performed these tests with Nissan stock, HI v1 and HI v2, PEX and AMS pulleys
All installs were performed on the same motor, which has a brand new Nissan water pump installed.

Here are the stock, AMS & HI v2 side by side:

Stock pulley:

Stock pulley belt offset @ 20mm from timing belt cover:

HI v1 Pulley:

HI v1 pulley belt offset @ 20mm from timing belt cover:

HI v2 Pulley:

HI v2 pulley belt offset @ 20mm from timing belt cover:

PEX pulley:

PEX pulley belt offset @ over 22mm from timing belt cover:

AMS pulley:

AMS pulley belt offset @ over 22mm from timing belt cover:

As stated before, the AMS water pump pulley is offset/backspaced incorrectly and causes drive belt misalignment between the water pump, crank and alternator pulleys. This will cause incorrect loads on the water pump and will with time prematurely wear the pump's bearings & seals.

Additionally I placed both the AMS & HI v2 pulleys onto a standard shipping scale. The scale was calibrated to "0" before each item was placed on it. Given the holes cut into the mating surface of the AMS product the results might surprise you.

HI v2 4.4oz

AMS 4.8oz