Water Pump Comparo
Post date: Jan 25, 2012 5:07:15 PM
So most water pumps from the parts stores are cast iron with stamped impellers. Not all that great. Since the top end of the engine will be aluminum, I wanted an aluminum water pump. If you go searching, you'll find FlowKooler advertises their pumps very well, but have a pretty bad rep.
I bought a Moroso pump from Year One - they actually had a decent price! - and was shocked to find it's just a stock GMB pump in a Moroso box. Stock GMB stampings and everything. Yeesh,
It appears that the only particularly good pump is the GMPP one, but it's getting very hard to find. Some stock pumps had cast impellers with a solid backing, but the vanes end up pretty small on those. In general, the open vanes create more turbulence and less flow than a pump that has a backing plate.
Oh well. Could've saved some cash by just getting the GMB.