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MGB overheating 63 mgb solved :]

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Philsmgb

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The car is a 63 which would have a 3 main engine. My 63 mgb has a 65-67 motor which is a 5 main motor. Here is where the problem came in my 5 main engine had a 3 main water pump which could not move enough water to keep the engine cool thus the radiator stayed cool and the engine stayed very very hot. The only noticable difference in the water pump is the fact that the 5 main water pump has an impeller which is twice the size of the 3 main water pump moving much more water through the motor. There you have it /ubbthreads/images/graemlins/laugh.gif mystery solved thanks to all that made suggestions and helped.

Phil
 
Outstanding Phil. Enjoy
 
Thanks Phill, Another great piece of news to add to our memory banks. A 3 main engine water pump is different than a 5 main pump even though they will bolt up the same. With this info You could have possibly solved some others heating problems. /ubbthreads/images/graemlins/thumbsup.gif /ubbthreads/images/graemlins/thumbsup.gif PJ
 
This old guy wonders if the reverse is true? Will a 5 main water pump bolt up and work in a 3 main engine.

What would that do. Well I'm not sure, it would move the coolant faster and not allow it time enough in the radiator to actually cool down maybe, or it just might cool off a hot engine in the south west. Do not know really. Just a thought.
 
That's a good question Jack. I wonder if the water jacket is smaller in the 3 main engine and wouldn't allow a larger or later model impeller to fit in? /ubbthreads/images/graemlins/tongue.gif PJ
 
We need an expert here, Hap, Carl, Pat??
 
I've made a note of theis as the 3-main engine for my '63 B is disassembled, machine work finished & awaiting reassembly.
 
I know my hopped up 3-Main MGA motor runs a lot hotter than a stock 1800....

There must be some other important difference....
(Other than impeller)
 
3-mains have less friction than 5-mains...so, do they hop up faster?
 
Hummmm......On a nice day, I know the lil' car really wants ta go zoom.

I have heard the same about the 3-5 main, thing.

Can't imagine it is much if anything.
 
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