4020 Cooling system question, water manifold.

4020_1966 · Oct 18, 2014

(66 4020D)
I put the water manifold and thermostats in and bolted down. While I was there I put new hose sections on manifold bypass pipe. At first I thought the bypass was to be a back up in case the thermostats wouldn't open but then I noticed it also connects to the head above the #6 cylinder. At first I thought it was to help cool the 1, 6 cylinders as they are the farthest from the thermostats. But the #1 cylinder doesn't have this. So what is the reason for this #6 coolant bypass?

Bob · Oct 18, 2014

The bypass allows coolant flow through the engine to avoid hot spots before the coolant at the thermostat is hot enough to open the flow path through the radiator.

It probably aids in venting air, as well.

4020_1966 · Oct 18, 2014

Ok that makes sense. Thanks Bob. I still find it odd that #1 doesn't have it as well. The therms are centered above 2-3 and 4-5.

tim s · Oct 18, 2014

There is a large passage way under where the stats bolt on, the bypass is just what it is, letting water "bypass" the states when they are closed, and vent the head of air....

Bob · Oct 18, 2014

IIRC, water pump discharges INTO front of head, bypass takes water FROM the back of the head, to the water pump intake side.

4020 Cooling system question, water manifold.

4020_1966

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Bob

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4020_1966

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tim s

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Bob

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