Reasons to add an overdrive?

ivoryjohn

ivoryjohn

Senior Member
I have the bit in my teeth and a fair wind on my stern, no wife or anyone to give me pause for caution except my Brother Barners. My question is why I should not pop for a new Mitchell Overdrive for my Model A.

My engine has just at 1000 miles since being put right by James Rodgers Mississippi Guru A. Danner. It has a H.C. head, a newly rebuilt ******, and is ready for touring. I want a Mitchell Overdrive because I have ridden in a Fordor like mine with one and it just purred along at 55mph without a bit of strain. Also a buddy has a 37' Pickup with a Mitchell and he highly recommends his setup with a flat-head. V-8.

Give me your best shots! Why shouldn't I install one if I want? I am not going to go completely over to the dark side and start chopping and lowering the top....adding a chevy engine.

Whatever your reason......including, "It ain't Henry" will be contemplated before I pull the trigger and put my money down. But hurry up guys I am winter board and want something to do like installing a Mitchell, before I start fixing what ain't broke.
 
John,

In Increasing forward speeds it would only be wise to increase stopping power.
As it stands, The Model A's brakes have never been much more than adequate
for the task at hand.
The natural tendency to make hay will only demand more of your brakes and driving skill.
I trust you have the skill, do you trust you have the brakes?

A simple and easy (Inexpensive! $30) upgrade is floaters for your front brakes.
http://www.ebay.com/itm/1928-1931-F...Parts_Accessories&vxp=mtr&hash=item1c2ee7d6ae

A more expensive/complicated root is juice brake conversion and that
is what usually starts one in thinking they then Need the V8, chop top, fuzzy dice and dingle balls.


jmho


moe


.




will only mean that you should also
 
A properly redone A should have no problems running 60 MPH all day long after all that is what Ford designed the car to run. The 30 fordor I owned was not properly redone and was happy running 55 MPH all day long. My brothers coupe has always been run 60 to 65 MPH all day long. In fact, we tried to kill the babbitt we put in it on a trip from NJ to WI. The car got more than 20 MPG running 60 MPH all day long.

Keep in mind the above 2 cars were basically Ford Factory with the exception of the used B cam in my brothers car. My brothers car has been on the road since about 1970.

So do you need an overdrive, well how much do you really drive the car? Then how much do you really drive the car over the highway?

Certainly there are some advantages by lowering the rpm at the engine. I believe there is a psychological factor from a perception of the engine reliability perspective. So many are used to the horror stories of engine failures because the engines were poorly rebuilt. So many feel the original engine is inadequate. So they 'HAVE' to put the overdrive in the car.

In reality most guys would be fine with a properly balanced engine and a properly built chassis. The few that regularly run long multi state trips are the ones that have the real need for the overdrives.

It is a lot of bucks and in the end it is you that needs to think how you really drive. You already spent some bucks on an engine that should be built properly so you should expect 50,000 miles (or more) of trouble free driving at a mix of highway speeds.
 
I agree with Tom, either or for an OD or a taller gear.
Moefuzz, I love your avatar! However I disagree somewhat, juice brakes are better, that's why all cars today are using them. However as many guy's here on the barn will attest, the factory mechanical brakes on the A if set up properly will provide every bit the stopping power that you need at 60 or so. You don't even have to have floaters if all the brake parts are in tolerance and in their respective places. Here are a few threads that I used the search function to find that back up that opinion.
http://www.fordbarn.com/forum/showthread.php?t=89439&highlight=brakes
http://www.fordbarn.com/forum/showthread.php?t=44591&highlight=brakes
 
Thanks for the links, just acquired a new A (29 Tudor, 58,000 miles, one owner) and need to bring it back into driving condition.
First things first was getting it running (2 weeks ago)
Now need to address tires, brakes, lighting and swap all the grease nipples out.
This is my 3rd A but only 2nd factory (banger) powered car.
-It's been a long time since I sold the 31 rumbleseat so I need a tuneup as much as the new Tudor does..
Thanks again,


moe


.
 
Why do you need to switch the grease fittings?

If they are original now, then just use the original grease gun or buy an adaptor for a modern grease gun. I like the original fittings and use my original gun, and they work great.

If they are now modern fittings, then I can understand you wanting to return to original fittings.
 
I think an overdrive over the 3.27 ratio is a good option for a Fordor because of it's weight and possibility of passengers. My Model T is pretty zippy, but when four are aboard it's a real dog. Granted, an "A" has twice the horsepower, but weight is still a performance handicap. It would be nice to be able to "opt out" of the long legs on some occasions and just run out of o.d. That being said, the extra stick on the floor kind of ruins it for me, like an altenator on a nicely restored engine.
 
One thing that has not been mentioned yet is the reduced engine noise that the reduced rpm's of the engine make. At 60 mph, and yes a properly rebuilt Model A engine can run at 60mph all day long and it will not hurt it, But the engine is turning close to 2500 rpm and over several miles that engine noise grates on the ears. Reducing the rpm reduces the engine noise dramatically. Your ears wiill thank you. Trust me I know and I am almost deaf so my wife says.

In 3rd gear at 60 mph your engine will be turning approx 2500rpm. In overdrive, assuming a 26% OD, your engine will be turning approx 1850 rpm.
 
One mo thang. With properly built Mechanical Brakes you should be able to slide all four tires on pavement. Juice brake dont any better than that.
 
I have to agree that properly adjusted brakes can skid all four tires on pavement. I use a temperature gun to measure how hot the drums are after some hard braking. I adjust the coolest one in a little bit and retest. Once all the drums are around the same temperature, they grab just as good as hydraulic brakes.
 
I've had an overdrive for 25 years, don't drive a ton of miles, don't usually run over 50 MPH, and have been happy with the set up. With lower RPM's, the engine noise is greatly reduced, and conversations with passengers, especially my wife, are greatly enhanced and more enjoyable. Be careful not to run the overdrive at low speeds, because of "lugging" the motor. Life is more enmjoyable at less than 50 MPH. What's the rush?
 
I had an overdrive and took it out. Life is more enjoyable at 50mph. If I'm in a hurry I take the modern vehicle. To each his own, if you feel better with an OD get one and enjoy it !
 
I run a Mitichell in a late 31 town sedan. 50k miles and no prombles. Mech Model A brakes are the best,may take more than one try at getting them right but you will be happy with them.Wish you the best of luck. tom
 
Here's the dumb answer you've been waiting for... But you said you'd consider it, so here goes... :)

Why not just accept the fact that you bought an antique car, and enjoy it for what it is?

Drive 40. Avoid highways. Putt along like grandpa. Don't keep trying to modernize the car so it keeps up with modern traffic. Just enjoy it as it was originally built. The alternative is to keep upgrading for faster and faster traffic as the years go by. But if you stay on that slippery slope, in 20 -30 years you'll no longer have an antique car; it'll be just another hotrod.

When I drive my A, I intentionally drive slow, listen to the sounds of the road, and watch the fenceposts go by. Sappy? Yes, but that's why I bought an antique car in the first place. So I could be sappy and nostalgic. My kids think I'm nuts.

To me, the "antiqueness" is not just to look at; it's to experience with all your senses. (You can always jump back into your modern car for modern speeds.) But when you're in your A, you get the full old-timey experience in all it's glory. Add an overdrive, and you instantly give up a portion of that.

Think about it... did you really buy your antique car for more freeway driving and more of the hectic modern lifestyle? If so, the OD may be just the ticket.
 
Great answers! I was afraid I was going to start a hen party way in left field over, As Henry built it and Anti Rat Rod. Things have fallen apart before in those directions.

As a note I have four wheel Ted floaters and steel drums for brakes and have just about run out of things to hang on my poor car. Some of us old crazy people start spending their Sociable Sincerity chit on things for their dogs and treats for their cars. I was a little afraid a Mitchell would be one of those things.

I have so far resisted installing a rock guard and glass shift knob as being excessive because I need to leave something for the next caretaker to put add.
 
I do not have a overdrive drive in my car I drive 40 - 50 mostly on local roads. If the way you are driving the car now makes you feel like you need to be able to go faster for greater distance then put in the overdrive , you can always remove it and go back to the original setup.
 
OD's give the best of both worlds. You still have the low gears for pulling away from the stop sign or pulling hills, but you don't have to use the OD all the time. The OD gives really nice cruising at speed. Cast iron drums are better than the original steelies. Of course I like glass shift knobs too!!!
 
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