Temp variance between cylinders

[Will N]

Originally Posted by James Rogers

If all this is true, what is up with my Model T? I have 2 and have never run a water pump on either and never will. The cooling system is virtually the same on the T as it is on the A but I never experience overheating in it even in Utah in July or South Dakota same month or TN in August on a asphalt parking lot idling. I have seen ambient temps as high as 102 and no overheating even on a long pull.

The Model T is only 20 HP, and HP=Heat. The T doesn't have to get rid of as much heat as the A has to. The natural circulation of the thermosyphon is not impeded by or overidden by the water pump as in the A, which as Bob B mentioned, forces the water to take the path of least resistance from the inlet to the outlet, bypassing the rear of the block.

[James Rogers]

Originally Posted by Will N

The Model T is only 20 HP, and HP=Heat. The T doesn't have to get rid of as much heat as the A has to. The natural circulation of the thermosyphon is not impeded by or overidden by the water pump as in the A, which as Bob B mentioned, forces the water to take the path of least resistance from the inlet to the outlet, bypassing the rear of the block.

I don't really believe that. I have a 94 Ranger with the Mazda 2300 engine that had a water pump with a detached impeller that would never even get up to operating temp till I replaced the pump. I couldn't figure out why it wouldn't work the heater till I found out the water was not circulating through the heater core. The previous owner had replaced the radiator and heater core with new and never found the problem. As with any motor with cylinders in line, the #4 cylinder had gotten hot simply because the back cylinder on any motor will be hotter but without circulation of the pump, it burnt an exhaust valve. Replaced the head with a rebuilt and replaced the pump and 12000 miles later it is working like new. BTW, this motor is 90 HP so, according to your estimation, it should have burnt up in a very few miles.