DeTomaso Mailing List: March 2000, Message #155

Ok...
Soooo the water returns from the heater to the upper inlet on the pump.
The old pump routed this water back into the block via the internal
passage,which the new pump does not have.If you look closely,you'll see
the difference,no passage-
http:members.aa.net/~mattwell/waterpumps.htm
If I use the new pump and hook it back up like before as you're
describing,water will go into the upper outlet and dump straight into
the impellar cavity and not through the passage.The passage wont be used
at all with the new pump.
This doesn't seem right to me.Why else would they have put it there?Is
it neccesary?
Are all 351C's this way? 

If so,why doesn't the new vendor ordered waterpump have provisions for
the internal passageway already? 

Thanks again,
Matt
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JDeRyke@aol.com wrote:
> 
> In a message dated 3/5/00 5:58:11 PM, mattwell@aa.net writes:
> 
> << It looks like I'll now have to route both heater hose outlets through the
> 2 water pump outlet fittings.The old stock pump routed fluid through the pump
> body,into the block outlet,with a plug on the lower of the 2 outlets. >>
> 
> If you look closely, both waterpump ports are inlets entering the same cavity
> in the pump. So, plumbed that way, there will be virtually no water flow thru
> the heater core. One heater hose (from below the console, just in front of
> the crank pulley) should be hooked to the block for hot water flowing TO the
> heater, the other for slightly cooler return water FROM the heater to the
> water pump, then to the block. This's why you can sometimes supplement an
> overheating radiator by turning on your heater & fan. I advise using the
> upper of the two outlets, as the lower boss on a Weiand 8209 is very thin and
> sometimes cracks when you really tighten a pipe fitting into it. Carefully
> plug the lower & screw a pipe bib into the upper. Don't forget your manual
> shut-off valves, either... Cheers- J DeRyke