TR4/4A Crank shaft pulley for electric fan conversion

[Chasman3]

I isolated the noise that I thought was a water pump by removing the belt on my TR4. It has an electric fan conversion with long neck aluminum radiator. I discovered the crank bolt was finger tight! I took it off and the pulley came off feely. The 1/2 moon woodruff key was in place. But the key way in the pulley is worn giving it side to side movement. I need to replace but don’t know where this conversion would come from? Here is a picture. Any help very much appreciated. Good news crank end is fine. And when I started it to check for noise, wonderful quiet. Just the gentle exhaust rumble and gentle valve train. Thanks again. Charlie

 

[malbaby]

That is a very strange looking pulley, and IMHO not at all suitable, so I would not replace with the same design [even if you can find one].
Appears that someone has welded a spacer onto that pulley, rather than a seperate spacer slipped over the crankshaft end, behind the pulley...That is why it has come adrift...The pulley was probably never fully tight when first installed.
There are probably balancer pulleys available from TR suppliers that are suitable.
On my car, I did a conversion using a specific thickness spacer on the crank and a Aussie Holden dedicated harmonic balancer, whch is an exact fit onto the crank.