Return line into motor from Heater location?

[Neli]

Trying to hook up heat in my '04 85XT, anyone please tell me where the have seen the return line run into the block? There are three options that I see, I would like to use the large one by the oil filter, just rear of the block heater....any suggestions? Thank you for any help! Neli

 

[skidsteer.ca]

The heater return has to go to the suction side of the water pump.
Many engines have a external pipe going from below the thermostat back to the water pump. Others have it cast into the block. Either way there has to be a way for the hot water to return to the bottom of the engine while the thermostat is closed.
The coolant circulates around the block until the temp rises enough that the thermostat opens. Then some of the hot hot water goes to the rads top hose and cold water comes from the bottom of the rad to replace it. The balance continues to circulate in the block and heater loop.
When I did this on my 853 I put a restriction in this pipe from the thermostat to the water pump then returned the heater loop between the restriction and the water pump to insure the heater loop would circulate. Here are some pics.
This is a Iszuz engine, yours will be somewhat different of course.

The brass nipple is the heater loop pressure or supply and comes from the gallery just below the thermostat.
In the next picture I'm pointing at the return to water pump pipe for that the heater loop returns into. Suction side.

Hope that helps some.
Skidsteer.ca

 

[williamhejlik]

The heater return has to go to the suction side of the water pump.
Many engines have a external pipe going from below the thermostat back to the water pump. Others have it cast into the block. Either way there has to be a way for the hot water to return to the bottom of the engine while the thermostat is closed.
The coolant circulates around the block until the temp rises enough that the thermostat opens. Then some of the hot hot water goes to the rads top hose and cold water comes from the bottom of the rad to replace it. The balance continues to circulate in the block and heater loop.
When I did this on my 853 I put a restriction in this pipe from the thermostat to the water pump then returned the heater loop between the restriction and the water pump to insure the heater loop would circulate. Here are some pics.
This is a Iszuz engine, yours will be somewhat different of course.

The brass nipple is the heater loop pressure or supply and comes from the gallery just below the thermostat.
In the next picture I'm pointing at the return to water pump pipe for that the heater loop returns into. Suction side.

Hope that helps some.
Skidsteer.ca

on my 70 xt it is somewhat under the alternator, or that genral area, i didnt look real hard because it was already there when i got it