Water pump ports...which is send/return?
Water pump ports...which is send/return? i am installing a custom a/c with my LS1 setup and am needing to know which of the two ports on the water pump is the send and which is the return.
thanks,
thanks,
Weird, I replied to this thread yesterday and now it's missing. The port on the bottom of the pump with the thermostat is the outlet. Water flows from the engine, to the pump, to the thermostat, to the radiator.
Originally Posted by HavATampa
Weird, I replied to this thread yesterday and now it's missing. The port on the bottom of the pump with the thermostat is the outlet. Water flows from the engine, to the pump, to the thermostat, to the radiator.
stat is on the inlet side of the pump. Should draw from the low side of the radiator. Pump feeds the lower ports on the block, upper ports receive water from the heads, combine them in the pump body, and feed the now hot coolant out the upper port on the pump into the top of the radiator.
The heater lines provide a bypass around the stat while it's closed, allowing ths motor to come up to stat temp.
i think i may have been unclear in my post and my question. i am referring to the ports that go to and from the heater core...not the main water ports. there are two ports side by side on the water pump next to the thermostat housing. one is smaller in diameter than the other. i am trying to determine which of these two ports is sending fluid to the heater core and which is for the return line from the heater core.
thanks,
thanks,
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My bad, didn't mean to mislead anyone. I did a search on this topic and didn't find anything so just assumed the flow was the same as the old engines with it heading out of the block to the t-stat and then to the radiator. Having the t-stat at the bottom is a strange setup. Curious on the bypass setup though that you mentioned. If the the t-stat is closed and the water is being diverted to the heater core hoses, what's stopping the heater core from warming up the inside of the car?
Originally Posted by y2khawk
incorrect.
stat is on the inlet side of the pump. Should draw from the low side of the radiator. Pump feeds the lower ports on the block, upper ports receive water from the heads, combine them in the pump body, and feed the now hot coolant out the upper port on the pump into the top of the radiator.
The heater lines provide a bypass around the stat while it's closed, allowing ths motor to come up to stat temp.
stat is on the inlet side of the pump. Should draw from the low side of the radiator. Pump feeds the lower ports on the block, upper ports receive water from the heads, combine them in the pump body, and feed the now hot coolant out the upper port on the pump into the top of the radiator.
The heater lines provide a bypass around the stat while it's closed, allowing ths motor to come up to stat temp.
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Originally Posted by y2khawk
incorrect.
stat is on the inlet side of the pump. Should draw from the low side of the radiator. Pump feeds the lower ports on the block, upper ports receive water from the heads, combine them in the pump body, and feed the now hot coolant out the upper port on the pump into the top of the radiator.
The heater lines provide a bypass around the stat while it's closed, allowing ths motor to come up to stat temp.
stat is on the inlet side of the pump. Should draw from the low side of the radiator. Pump feeds the lower ports on the block, upper ports receive water from the heads, combine them in the pump body, and feed the now hot coolant out the upper port on the pump into the top of the radiator.
The heater lines provide a bypass around the stat while it's closed, allowing ths motor to come up to stat temp.
I love it when I actually find the info I need by searching!
Thanks!! 
Im curious as well. I want to install a valve on the feed side to completely shut off the heater core for summer driving rather than just looping it and having my heater core lines hanging out of the firewall.
For the heater core lines.. they are like most other systems.. smaller is usually the pressure or out going feed, the larger is the return line, this goes for the power steering pump and your AC lines too if you take note.. this is a good general rule of thumb.
You can get a heater bypass valve from a junk car or yard. Or Buy a new one. Some of them are controlled by Vacuum or cables from your HVAC control panel.
Some of them just block the passage, other will re-route it to be returned.
Check with your local parts store and ask to look at the catalogs.. I think my is out of a Ford Truck/Bronco (84'ish) that is vacuum controlled like my Chevelle original system and re-route the flow back, as I could not use the original Chevelle one which mounted on the intake manifold, the one I have now is inline with the hose.
I think I have the part number someone in my documentation, If I find it, I will post it.
You can get a heater bypass valve from a junk car or yard. Or Buy a new one. Some of them are controlled by Vacuum or cables from your HVAC control panel.
Some of them just block the passage, other will re-route it to be returned.
Check with your local parts store and ask to look at the catalogs.. I think my is out of a Ford Truck/Bronco (84'ish) that is vacuum controlled like my Chevelle original system and re-route the flow back, as I could not use the original Chevelle one which mounted on the intake manifold, the one I have now is inline with the hose.
I think I have the part number someone in my documentation, If I find it, I will post it.
Well, I wasn't able to find my part number i used. but you can Google "Heater Bypass Valve" or "Heater Control Valve" and you should be able to find what you need, but just go to the autozone, kranges, etc and ask to look at the Catalog for the valves and there are usually a section that will have picture and sizes of the valves.
Heater valve on my car shuts off the flow when the heater is turned to cold. For LS1's going into E-36's this is the standard way of installing. I have seen no issues or heard of any from anyone else.
Thought I'dd add (already mentioned) that the outlet from the LS1 is 5/8 dia and the return is 3/4 dia (Outlet is smaller than inlet)
Thought I'dd add (already mentioned) that the outlet from the LS1 is 5/8 dia and the return is 3/4 dia (Outlet is smaller than inlet)
Last edited by Thaniel; Jul 6, 2009 at 11:29 AM.
