I decided to take a closer look at the water pump pulley and harmonic balancer on the DT today... I can't get the harmonic balancer off yet. But here's what I discovered at the water pump.
Nothing special here, just a view from the front:
You must be registered for see images attach
Here's a view from the passenger side of the engine looking down at the pulley with the squeeze sleeve (I don't know what you call it) loosened but not removed:
You must be registered for see images attach
And here's a pic with the squeeze sleeve removed:
You must be registered for see images attach
Nothing out of the ordinary, right? This is where it gets interesting:
You must be registered for see images attach
What I had thought was one deep pulley is actually two pulleys sandwiched together. And here's the water pump:
You must be registered for see images attach
In case you're wondering: yeah, it's frickin' huge:
You must be registered for see images attach
Clearly, when this engine was designed, space was not at a premium. In my application it is. I'm wondering if there is another version of this water pump that isn't so long. Something like 3" from the face that meets the block to the end of the threaded shaft (instead of 6 1/2"). Anybody out there know if there is such a thing?
The squeeze sleeve (whatever it's called) is an interference fit to the bushing on the water pump shaft. There are six 3/8" bolts that run through it, through holes drilled in each of the pulleys and thread in to the flange behind the bushing on the water pump. I assume it's assembled this way because originally this engine came with an air pump for the bus brakes. If I run an air pump, it's going to be electric. So this water pump pulley design just isn't needed. I'm thinking if I can find a different water pump, a different water pump pulley and an ag harmonic balancer, I should be able to gain a few inches of clearance in the front where space is at a PREMIUM.