Charles Durning's Journal --
Off With Their Heads Part 2 I tried my best to avoid project creep when I had the head off of the Morris, but alas I gave in. If I recall correctly the BMC A and B engines have a problem with burning the #4 exhaust valve. The theory here is the coolant does not circulate well at the back of the head. VP Steve reminded me of that theory. His solution is to leave the heater valve open a bit so water can circulate around the back of the head and then out into the heater circuit. Well the thought of hot water circulating through the heater on a hot summer day just didn’t appeal to me. With that in mind I hatched a plan. Why not plumb in a bypass so coolant could circulate out of the back of the head and return to the water pump or radiator. There is a place on the back of the head where the coolant is under pressure. Unfortunately, that port is occupied by the heater valve. To make this work, keep the heater control valve, and not circulate coolant into the heater would be to tap the water flow after the head and before the heater valve. No problem. I just needed to modify an earlier heater valve conversion. The original used a fitting to raise the replacement heater control valve above the valve cover for clearance. All I would need to do is substitute that straight fitting with a “street tee”. That worked. All that is left is to tap into the heater return hose with a hose tee. Now the coolant can bypass the heater and can circulate out of the back of the head and in to the water pump. After a 100 mile jaunt through the back woods of Simpson County the cylinder head temps taken near the spark plugs. All are within 5 degrees of each other. I hope that is a success since I had not taken those temps before removing the head. Confidence is high.
Posted 2021-05-31 13:42:38 by charles durning
Off With Their Heads Part 2 I tried my best to avoid project creep when I had the head off of the Morris, but alas I gave in. If I recall correctly the BMC A and B engines have a problem with burning the #4 exhaust valve. The theory here is the coolant does not circulate well at the back of the head. VP Steve reminded me of that theory. His solution is to leave the heater valve open a bit so water can circulate around the back of the head and then out into the heater circuit. Well the thought of hot water circulating through the heater on a hot summer day just didn’t appeal to me. With that in mind I hatched a plan. Why not plumb in a bypass so coolant could circulate out of the back of the head and return to the water pump or radiator. There is a place on the back of the head where the coolant is under pressure. Unfortunately, that port is occupied by the heater valve. To make this work, keep the heater control valve, and not circulate coolant into the heater would be to tap the water flow after the head and before the heater valve. No problem. I just needed to modify an earlier heater valve conversion. The original used a fitting to raise the replacement heater control valve above the valve cover for clearance. All I would need to do is substitute that straight fitting with a “street tee”. That worked. All that is left is to tap into the heater return hose with a hose tee. Now the coolant can bypass the heater and can circulate out of the back of the head and in to the water pump. After a 100 mile jaunt through the back woods of Simpson County the cylinder head temps taken near the spark plugs. All are within 5 degrees of each other. I hope that is a success since I had not taken those temps before removing the head. Confidence is high.
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Posted 2021-05-31 13:42:38 by charles durning
