[Mg-t] MG TD failed water pump shaft

[William Putnam]

Greetings fellow MG T owners,
 
 Yesterday I had the unfortunate experience of the water pump shaft breaking in my TD.  This resulted in the fan blades striking the radiator, wrecking both in the process.
 
 I had installed a water pump that Phil Marino modified with a tapered interface between the pulley and the shaft.  The taper idea is a good one, I think, but it appeared that this was due to a crack which started at the base of the keyway, and then progressed until the remaining shaft could no longer support the load. Phil has offered to replace the shaft at no charge, and said this was the first of his shafts that he had heard about failing.  The pump had 3,007 miles on it when it failed.
 
 Has anyone had a Phil Marino water pump shaft fail?  Has anyone been running a water pump with Phil Marino's shaft?  Has anyone had a failure and not told Phil about it?  I'm trying to determine if my experience is a fluke or if there is a design or materials issue.  I think Phil is a great guy, does excellent machine work, and I know there are a fair number of T series cars running his shafts, but before I put the same type of shaft back in the car I'd like to have a little more peace of mind that my experience is unique.
 
 I am careful to not overtension the fan belt, and fairly regularly run 4,400-4,700 rpm on the highway (yes it's a bit much but I want to keep up with traffic, the engine has a Phoenix crank and rods, forged pistons, and Brown & Gammons valve springs), and will run up to about 6,000 rpm while racing.  So the engine probably sees higher revs than most street T series, but certainly not as high as some of the MG T race cars.
 
 Please let me know if you have run Phil's tapered water pump shaft, how many miles you have on the water pump, and if you've had any failures.
 
 Thank you,
 
 Bill Putnam