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Cuda
02-07-2004, 11:25 PM
The water pump that came with the engine has a three belt pulley. There was another pulley that would fit the bolt holes, but has a larger diameter. Did Merc make two size pump pulleys? It would in essence make the pump turn slower. I'd like to use the bigger one, because it looks like it's never been used. The other one is a bit rough.

gcarter
02-08-2004, 09:08 AM
Hi Cuda!
maybe I'm confused, but the only water pump with the Alpha One drive is the one in the drive. Unless you have fresh water cooling.
I'm only going on my experience of just removing mine.

George Carter

Cuda
02-08-2004, 09:09 AM
It's the circulating pump, just like on a car.

gcarter
02-08-2004, 09:12 AM
It's the circulating pump, just like on a car.
Thats my point, Cuda, there isn't one. Instead, there is a bypass. Look at the Stainless Marine, or one of the Mercruiser parts web sites.

George Carter

Cuda
02-08-2004, 09:15 AM
Nope, that's only if you use a cross over instead of the pump.

Here is the pump.

Rootsy
02-08-2004, 09:42 AM
yes mercruiser factory sbc's come with BOTH a pump in the alpha and a circulating pump on the motor... the circulating pump is not a self priming pump (neither is the one in the alpha) therefore it needs to be fed - same reason that the top radiator hose where it attaches to the radiator is ABOVE the C/L of your waterpump. also if oyu do not force feed your alpha (via hose water pressure) or submerge it in water... it will not move water, it must be primed..

now to answer your question cuda, the diameter of your pulley isn't going to affect things too greatly since it is supplied with positive pressure from the pump in the alpha. slowing it down a bit won't result in any appreciable temperature rise if any at all. THE BIG THING to pay attention to is that the pulley grooves line up... ie the groove on the crank, waterpump and alternator ALL LINE UP EXACTLY.. same for the waterpump, crank and Power steering grooves.. if not.. you'll throw the belt off... in short order...

Cuda
02-08-2004, 09:58 AM
Thanks Rootsy, it looks like a direct replacement. I'll put it on since it looks brand new.

MOP
02-11-2004, 11:02 PM
A thougth will slowing the circulation throughout the block and heads cause any hot spots?