I have just been inspecting a few MG water pumps, took a good look at
what I got so far. Verrrrry interesting.
The water pump I just took off of the early production 1500 engine looks
identical to the one on my later production 1500 engine, and I think
they're both original from the factory, both cast iron.
Then I looked at the one from an MGB 3-main engine. Looks identical in
all respects, except the front hub is held on with a hex nut while the
others are press fit, and the hub is thicker, more material at the back,
front surface is in the same place, 3-11/16" from the face of the engine
block, so completely interchangeable. The housings, inlets and impellers
are all identical.
The 5-main engine water pump is a different number, need to check out one
of those. Does anyone have a used one they could part with?
Several years ago I bought a new water pump from Moss for the 1500 as a
spare, never out of the box before today. Wow! This one has a die cast
aluminum housing. Due to the constraints of the die cast design, the
inlet port has a sudden squared off transition from the inlet bore into
the impeller chamber, with square edges all around the port and less flow
area. The iron ones have a smooth flared out transition into the
impeller chamber. So the aluminum one looks considerably more
restrictive at that point. Considering the marginal cooling capacity of
these engines, I'm not sure I want to use this one, except maybe in an
emergency. Anyone had any experience with one of these die cast aluminum
water pumps?
Considering the good luck I've had with water pumps, I think I'll put the
original one back on my fresh 1500 rebuilt engine.
Barney Gaylord
1958 MGA
|