Hi all!

Does anyone know the diameter of the water pump pulley on late 4M and 5M-E?

I'm almost finished with the rebuild of my MS55's original 2M, with a few modifications (5M points dizzy, late 4M crankshaft pulley, 150-amp alternator, Derale 15" 6-blade rigid steel fan and rear-mounted SU electric fuel pump). I had a new 102mm double-groove pulley custom-machined and pressed into the water pump, which results in the water pump speed being 39% faster than the crankshaft. I purposely did this to improve coolant and air flow when driving in heavy traffic.

I am wondering about the water pump pulley ratios on the 4M and 5M - did Toyota speed up the water pumps on these? On the M and early 2M the pump pulley diameter was 120mm and the pump-to-crankshaft pulley ratio was 1.08:1. On the F engine (on early FJ40s) the pump-to-crankshaft pulley ratio was 1.39:1 - the same as what I have now.

Cheers,
Jonathan