Re: cleaning intake chrysler 105hp 1971
The water flow is up the brass tube to the bottom of the block. There the tube is sealed to the block by a rubber grommet. above the rubber grommet the passage makes a 90 degree turn along the bottom of the match plate. That's why the coat hanger could not go any farther. At the edge of the match plate where there is a square headed pipe plug, the water again makes a 90 degree turn and enters the exhaust chest cooling cavity. From the exhaust chest it circulates around the cylinders, then passes the thermostat, and runs down the head to exit into the leg.
At the 90 degree turn into the exhaust cooling cavity, there is a dog-leg and nestled into this dog-leg is a diamond shaped cover. This holds and seals the water bypass valve. If this valve is stuck open by corrosion, then not enough cooling water will get to the head. Thus, you need to check the valve--not fun--you may snap the two bolts holding it. Usually though, the valve is stuck closed and/or/ the bypass is sealed closed with corrosion. This is not critical since later engine designs eliminated the bypass.
When you pour water through the thermostat, it runs down the head, exits the bottom into the leg and, of course, will run out the leg around the tube. If, when you push water up the tube, it does not exit at the thermostat opening but runs out the leg around the tube, this means that water is entering the exhaust cavity itself. This indicates that the exhaust chest gasket is broken or the stainless plate is perforated. It is time to remove the exhaust chest cover---ugh--likely to snap at least a couple of screws-- Remove the stainless plate and check the condition of it and the gaskets it is sandwiched between.
