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Discussion Topic:
1940 Ford Standard Coupe Rear Differential Upgrade
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dynamicpix |
07-26-2015 @ 6:59 PM
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Member
Posts: 8
Joined: Jan 2013
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Hi. I am working on a 1940 Ford Standard Coupe V8 60hp all stock. Im looking to upgrade the stock 4.44 rear differential to a 4.11 or another ratio if possible. Has anyone done this while keeping the original motor? Also if possible would it make a noticeable improvement and worth doing? Any advice would be greatly appreciated. Thanks Ron
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TomO |
07-27-2015 @ 7:02 AM
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Senior
Posts: 7250
Joined: Oct 2009
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My guess is that a 4.11 would result in a little less pickup and a quieter engine at speeds above 40mph.
Tom
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len47merc |
07-27-2015 @ 7:33 AM
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Senior
Posts: 1165
Joined: Oct 2013
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Ron - agree with Tom and add that another consideration is the speed, type of terrain and corresponding rpm you typically cruise at. A reasonable assumption is the 60 hp motor realizes optimum torque at an engineered/designed cruising speed for the time (likely 45 mph). If you change the rear to a 4.11 the optimum torque rpm (whatever that may be for a 60 hp motor - it is ~2,500 rpm for my '47 100 hp) will be realized at a higher speed for which air flow and wind restriction may exceed the 60 hp motor's power ability to comfortably and efficiently (i.e., without over-heating) maintain that speed, particularly over rolling terrain. Not to mention the suspension of the car was likely engineered to dovetail with these design/speed considerations as well. Something I'd give some thought to before making the change (typical cruising speed, type of terrain - slightly hilly, mostly flat, or mountainous - you typically drive on, optimum torque rpm, etc.). Perhaps kubes40 has some hands-on experience here as well that will help you make this determination. Steve
This message was edited by len47merc on 7-27-15 @ 11:54 AM
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kubes40 |
07-27-2015 @ 3:05 PM
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Senior
Posts: 3394
Joined: Oct 2009
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Okay, I guess I was kind of, sort of, asked for my .02¢ so here it is: LEAVE the 4:44 in place. I have had a few 60HP cars and even with the 4:44 they can barely get out of their own way when attempting to climb an aggressive grade. There's a reason ol' Henry but that stiff gear in there - it's necessary! Bottom line in my humble opinion? Leave it as it is. You will be sorely disappointed if you go to even a 4:11. A 3:78? Forget going up any hill... ain't gonna happen. Respectfully, Mike "Kube" Kubarth
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