The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 1968-72 Heater w/o AC

RichardJ · 07-02-2011, 07:30 PM

>>I am using a two outlet water pump on the engine<<

Are you sure they aren't both inlets?
Are you talking about a SBC?
The two outlet ports on the back of the pump push the water into the block. Water flows through the block, into the heads and out the intake manifold port to the heater and back to the suction side of the pump. If both of those ports you are talking about are on the same side of the pump as the lower radiator hose, then you have NO flow through the heater core.

My 292 had a 160 deg thermostat when I got it. Not enough heat on a cold winter night, but a 180 cured that.

07-02-2011, 07:30 PM	#8
RichardJ Registered User Join Date: Apr 2010 Location: So Cal Posts: 1,490	Re: 1968-72 Heater w/o AC >>I am using a two outlet water pump on the engine<< Are you sure they aren't both inlets? Are you talking about a SBC? The two outlet ports on the back of the pump push the water into the block. Water flows through the block, into the heads and out the intake manifold port to the heater and back to the suction side of the pump. If both of those ports you are talking about are on the same side of the pump as the lower radiator hose, then you have NO flow through the heater core. My 292 had a 160 deg thermostat when I got it. Not enough heat on a cold winter night, but a 180 cured that. __________________ '67 GMC 2500, 292, 4spd, AC