Re: 105 plumbing

[Simon Favre <simon@domain.elided>]

Dana Loomis wrote:

>I just acquired a 1750 GTV that has been sitting for a long time.  Some of
>the radiator hoses are missing, and I need some help figuring out which
>pieces are needed and how they're supposed to be connected.  The car is a
>1971 US model  (105.51) that originally had SPICA iniezione, but currently
>has a carbureted 1750 with Webers.  I'm not sure whether this is an
>original carbureted motor or a converted one: it has what appears to be a
>factory intake manifold, the dipstick on the timing cover, and a cam cover
>"dented" where the air intake is supposed to pass over.   
>
>What I'm puzzling about right now is the arrangement of the heater and
>radiator hoses.   The water pump has only two connections for hoses: one
>that is obviously for the lower radiator hose, and one that appears to be
>for a heater hose, which runs to it, but isn't connected.  The intake
>manifold is also slightly different from the ones I'm familiar with. It has
>two hose nipples on the rear:  one points straight backward and seems to be
>for the other heater hose, which is there but not connected, while the
>second one angles out from the right rear of the manifold.  This nipple is
>the same size as the other, but I can't see what is supposed to be
>connected to it.  There does not appear to be any bypass hose from the
>water pump to the thermostat housing.  

The timing cover with the dipstick indicates a "Euro" motor, or at least
the Euro timing cover. The water pump sounds like the one on the 1600, or 
it is also the Euro model. The later pumps have 2 small ports. The cam
cover sounds like the 1600 one. I don't think the 1750 Euro motors still
had the old air filter can on the exhaust side. I think your motor is a
grab bag of parts assembled by a PO. Hey! I've got nothing against that,
my 1750 is a grab bag. My car was a 1600 GTV, so when I put in a 1750, I
used the 1750 sump and timing cover with the dipstick on the exhaust
side, but I used the 1600 Weber manifold and cam cover including the oval
hose and the big air filter can. It looks stock until you notice the
dipstick on the wrong side, or you peer down at the little blank-off plate
where the Spica used to sit. ;=)

I think what you're missing is a tee in the plumbing. One heater hose goes
right to the manifold. The other goes to a tee. The other hoses going to
the tee are one from the manifold and the long one from the water pump.
The tee allows some water to circulate through the pump even when the
heater valve and thermostat are closed. If you don't have a heater to
hook up, I'd connect one manifold port to the water pump and block the
other off. You can block off a heater hose port with a short length of
hose and a copper end cap from the hardware store. I think a copper end
cap for 3/8" tubing will fit a 1/2" (13mm) heater hose with a clamp.

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