Bypass Fittings

My 67 F134 did not have the bypass fitting in the head (see hole). I need a fitting to go into that hole with a tube to match the one below in the water pump. However, block threads are 1/4 NPT, the water pump 1/2 NPT. How do you find a fitting that will accommodate the same tube size?? Could I bypass from the head to the water pump port on the left side of the water pump?

 

Funny. The parts manual I have (from 1971) doesn’t even show the bypass. However, I found a part number for the upper nipple (WO-649720). I was thinking of simply blocking both of these off with caps but read that overheating can occur if it is. Any other thoughts/experiences?

 

Do you just need a hose from one to the other? You should be able to get fittings in the correct thread with a simple clamp on hose nipple.

 

Use a reducer on the lower hose connection. These motors like to crack between the #2 and #3 exhaust valves. You just want to keep fluid moving so the hot spot stays in check it does not need full heater hose volume

 

The bypass cools the head, and was added when the intake valves went into the head, as versus the flatheads. I believe it was meant to keep the intake seats cooler if there is no coolant flowing from the heater circuit.

I've seen your problem solved with hardware store plumbimg parts.

 

I have an F Head on and engine run in stand in my Garage, I only run it a couple times a year. I plugged all three, just use the water pump to the head, maybe I need to look at that in FSM.