Columbia

S

svmsr1044

Senior Member
When an early Ford V8 (up to 48), was equipped with a Columbia 2 speed rear, what was the usual gear ratio when the Columbia was NOT engaged?
 
Couple of charts


549212

549210



Glenn
 
They were dealer installed or a shop that installed the Columbia not factory installed so whatever the gear ratio was from the factory.My '37 Ford with Columbia is a 3:78.
 
When using a 4.11 rear axle, in high gear the ratio increases to 2.9. You need a pretty strong engine to run a 3.78 or 3.54. I asked this question before rebuilding my Columbia, and I had plenty of helpful information. ( I’m still restoring this car so I can’t give a personal opinion here, but I was persuaded to use a 4.11 as the vehicle will need to travel up a mountain range so I have a nice low range and a comfortable highway gear, perfect for my 85 hp engine.
 
Ken, you can keep your '40 in overdrive and shift down to 2nd gear.


Assuming a 1.604 2nd gear in overdrive:


Final drive ratio = 1.604-1.604*0.285 = 1.15

Glenn
 
If you are contemplating an install, you need to take in consideration what size tires and weight of the auto that the Columbia is going to be installed into.


I'm running 3:54 gears with 7.00 x 16" tires, in a very light car with no fenders. I like the results. I don't make it a practice, but it pulls fine from a stop in 1rst gear high with my 9 inch clutch and cutdown flywheel with no slippage. With that said, I wouldn't get away with it if it was a heavy car.
 
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