Overdrive or 4 speed transmission or ring and pinion

[davew]

winter has set in and thinking of options. Would like to bump my speed from 45 to maybe 55. Would also like to do some longer distance touring. So-being new to the model A I'm looking at the four speed transmission conversions. People in Texas and California seem to have good ones and would look clean inside There is the mitchell overdrive but puts another shifter inside. But all kinds of gears. A higher ring an pinion, a 3:5 or 3:2 is also there but not sure if all the work and tools involved is in my ability level.Or just leave it as is. But it is fun to look at options. Seems like I always learn a little bit when I do. Anybody's thoughts would be appreciated. Thanks, David

[DaWizard]

David, I have also been wondering the pros and cons of increasing the speed limit of my A. My tudor came with a 3:70 rear end so one would think I can get another mile or two out of it. But I think what you need to do first is insure the brakes are capable of stopping you no matter what the speed, then be sure the engine is strong enough to get you up to whatever speed you desire. Now, once that is handled, the simplest thing to do is a high compression head and see if that gives you what you desire. If not, then I would see about changing the rear gears to maybe the 3:27, but you still need a strong engine for that, so this is the order that I would do the changes. If you are still not happy after all this, perhaps you might need a different car since that should be at about the limits of the stopping power of the stock brakes.

That is my opinion and 2¢ on the subject.

[plyfor]

Great question with probably many opinions. We've had Borg Warners, Peugots ('60's), Ryan and Mitchell in various A's and other makes.. Probably the simplest to install is the Mitchell by pulling the rear end only, with rear spring attached (need tall jack stands). One can install the cable or floor shifter. They both work fine.
We bought a tn sedan with the F150 4 speed OD tranny already done by Dave Delmue in Cal.., which is a pleasure to drive (but wouldn't do it if the prior owner hadn't done it.) The down side is the tranny is 2x the wt. of the stock tranny and the torque tube/shaft needs to be modified.Also, the shifter is further back from stock but is not an issue though carpet needs to be adjusted. A special bracket is needed for the brake/ clutch pedals as well as an AA flywheel housing .
Borg Warners are elec. and a reverse lockout feature is preferred to connect to the tranny . Ryan is out of business, btw.The Mitchell gives 6 speeds forward nice for hill climbing. Some folks like the Mitchell syncro stock type with the added OD package.

[Mitch]

David
We have some prior threads on the subject which I wiil link.. Regarding changing the rear ratio, with the stock trans i would only do a 3:27.. I put a 3:54 in Lucy and it’s not enough...

https://www.vintagefordforum.com/for...nd-experiences

https://www.vintagefordforum.com/for...ission-dilemma

[davew]

The brakes seem ok to me. The previous owner said that they had been worked on. Seem to stop it ok. I'm driving this with the same caution as with a motorcycle. The engine is a question mark. It needed a condenser shortly after I got it but that's it. Starts good, idles ok and seems to like to run about 45-47 MPH. There seems to be a bit of vibration to it. Has an oil leak but not to serious. I did a compression test all all cylinders were about 60 psi. I have not dropped the oil pan but will do that this spring when it warms up a bit. Non heated garage. Was wondering about the 3:2 gears. Do have hills around so maybe to tall?

[Mitch]

Do yourself a favor and don't take anyone's word for granite. Pull the wheels and check the brakes out along with the rest of the car. If you have not already, check out the thread in the chassis forum about "what to do once you purchased your car".

[davew]

I'll check that thread. Your right about the brakes . On my list for the next half way warm day.

[DaWizard]

Not so sure what you mean by "3:2 gears", but if you have hills you might get away with a HC head and 3:57 gears.

[davew]

I meant 3:27 rear end gears.

[Mitch]

I think your best bet is to go with an O/D unit or 4 speed O/D.. Your not going to get the results you're looking for with just a gear change

[davew]

Looks like maybe a mitchell

[tbirdtbird]

you need a strong motor to pull with the 3.27 gear set, like HC head, better cam, bigger valves, especially if any hills.

I put in a Mitchell, and love it. I am never sure of what the issue is with the 'extra lever'......so what?
When at a nice restaurant and they give you a dessert fork, do people complain about too many utensils? That is what the Mitchell is, dessert.
If you have an original floorboard, and don't want to cut it, then get a re-pop floor, cut that, and stow away the original for safekeeping.
I like to do some performance mods because of the extensive touring we do, but I would never do anything to the car that can't be put back to original

[Dennis]

X2 on all of what tbirdtbird said. I'm patiently waiting on my Mitchell. Might be another 5 weeks. Like ^^^ said I have an original hardwood floorboard in pristine condition I'm not about to cut a hole in, so it's down to HD for one of those multi layer pieces of plywood for me.

[davew]

I'm sure the floor is not original so no issue there.

[BNCHIEF]

What Tbird said and then some I would never do anything that can't be undone.

[Ray Horton]

I would suggest before you do anything else that you get out and drive what you have at 55 mph and see what it feels like to drive an 87 year old vehicle at those speeds in today's traffic. If you're comfortable with that, then ask yourself if you want to invest the time, money, and aggravation to make the necessary mechanical adjustments to cruise at that speed. By the way, a good restored engine will do 55 without any additional mechanics. But whatever you choose to do, keep in mind that the condition of the rest of the car has to measure up to the increased demands of higher speeds.

My cars are all stock, and they will do 55, but I don't drive them that fast for the simple reason that they will not respond as quickly in an emergency situation as a modern car, and that is too much of a risk to take for an extra 10 mph. I'd rather get where I'm going safely than quickly. If I'm in a hurry I drive my Honda.

[davew]

I agree with the comfort level. I've had everything from sports cars to muscle cars. Retired a few years back and now at the age of 72 picked up my first A and am enjoying it. Except that it's now in the shed until March. Guess I'm just thinking out loud.i really appreciate everyone's insight to this question.

[davew]

I read the thread on what to do once you purchased your car. A lot of good information. check your checking account seems to be true

[CarlG]

I’m a little prejudiced, but the F150 4-speed OD, 3.78 rear, 5.5 head give me everything I want. If you get the transmission kit from Dave, it comes with all you need for a bolt on installation. I would definitely follow this path if I had to do it all over again.

[carolinamudwalker]

Times two

[Tom Wesenberg]

All my A's are stock, but for a car you want to drive a lot, I'd like to have the same set up as Carl.

[BNCHIEF]

You will have a six month wait on that Mitchell I know I did.

[George Miller]

I run the F150 also, I did my own mods. It works well. But never had a problem with driving any of my past model A's 55. that is the speed our club goes most of the time.

[Tom Wesenberg]

I would also want a crankshaft with counterweights. This helps smooth out the engine and really helps the life of the main bearings, especially the center main.
And the faster the engine spins, the more important counterweights are.

[BNCHIEF]

x2

[WMWS]

An overdrive is the best modification I have made to my 28 Tudor. I happen to have a Mitchell but anything to get the RPMs down makes driving the car so much more enjoyable. At 1750 RPM I am going 53 MPH with my 3.78 rear and in OD. Try going 53 in your car and see how it feels. Then drop down to 1750 RPM which would be 39 MPH with a 3.78 rear and notice how much more relaxed the drive is.

[davew]

I've had it up to 55 which seemed like I was pushing it. At 40 it could go all day. I'm thinking Mitchell or OD would be the way to go.

[CM2]

I'm building for the freeway,I currently have the following:

cast iron drums,woven brakes shoes with floaters
F100 steering box
Mitchell OD
3.78 rear
engine in process,sleeved to stock,B grind cam,McEachern gears,full flow oil filtration,stock crank with fresh babbit,B flywheel balanced with clutch
12v alternator
Holley 94
16" ford wires
215/75 r16 tires

in search of or buying in the future:

single downdraft intake manifold
mechanical advance distributor (mallory,B,bubba's)
6 to 1 head
cherry bomb the model a exhaust manifold,but might run a header in time.

I agree with Tom on the counterbalanced crank, but the mechanical advance distributor should protect the center bearing as well.Brakes came to me professionally restored so stopping shouldn't be an issue,coupled with the radials skidding shouldn't be either,hoping for 50 to 60 hp on this engine build, that should be attainable with good torque given the parts I'm using..55 to 65 cruise,light sport coupe body..if all goes right Ill be able to pull Donner Pass for hot august nights in Reno..

[AL in NY]

I, like George Miller, did the F150 conversion myself. It's the best $900.00 I ever spent. Would recommend it to anyone wanting OD/more speed/less RPM's........

[Paul K.]

I installed the F150 and did my own mods like George Miller.. Run 3:78. Like the setup. Currently getting engine balanced.

[Gary D]

I have a 1930 Model A Cabriolet, 3.78 rear, with a World Class Borg/Warner T-5 transmission, using DexronIII/Mercon ATF. It shifts effortlessly, is great for climbing, perfect RPM's at 55 MPH, and 21+ MPG on trips, plus no extra lever to deal with. Local roads I use mostly 4th gear, on open roads 5th gear. This is not a knock on the Mitchell unit as I know others that have them and they are very happy with their engineering and performance. GD

[AL in NY]

For those of you who can't afford the $3800.00 for Dave Delume's F150 4 speed kit and have good mechanical ability, there is an another option. Mac's speed Shop in New Zealand offers a bell housing and rear adapter plate for the F150 transmission that really cuts down on the amount of machining that needs to be done. The costs are $465 and $175 respectively plus shipping. The transmission output shaft needs to be shortened, but that can be sent out to Moser Engineering in Portland, IN. The easy part of the build in shortening the driveshaft, torque tube and radius rods. Your cost will be thousands less the Dave's kit.

[old victoria]

it does not take much to turn a rts trans into junk when trying to do it on your own, (I know they send me whats left to try and save) Its NOT an easy conversion . do your homework before jumping into a project like this. parts for these transmissions are very hard to find so if you trash a part you may not be able to find another.

[Mitch]

Here is a Mitchell O/D technical thread that was just completed

https://www.vintagefordforum.com/for...overdrive-info

[H. L. Chauvin]

All above is very helpful extremely valuable information.

Maybe in your considering:

A. "Would like to bump my speed from 45 to maybe 55;", and,

B. "But all kinds of gears;" and,

C. "Or just leave it as is;" and,

D. "Anybody's thoughts would be appreciated. "

If you are stock and original, the suggestion to get out on highways where you intend to travel and get up to 55 mph for that different Model A "feel" appears like a most wonderful suggestion.

Also, try experiencing road handling on back road bumps and/or any Interstates at 55 mph in something like a Toyota Highlander and also later in your Model A to notice a very "slight" difference.

Maybe an extra shift handle coupled with continually adjusting the spark handle, (and possible GAV adjustment at abrupt stops), can make a Model A driver "slightly" resemble a busy grocery clerk at a busy check out counter checking out groceries. ??????

Just one (1) choice: I went with a 3:27 rear, a Stipe "B" cam, used the "Police HC Head" that came with my supposedly "heavy" 1930 Town Sedan, and have no problems in hill country with (4) passengers.

(Hmmmmm : At 1,900 engine RPM's, approximate Model A speeds depending on tire sizes for different differential gears: 3:78 = 43 MPH; 3:54 = 47.5 mph; 3:27 = 51.5 mph; hence, on a 200 mile Model A trip a 3: 27 set of gears will allow one to arrive approximately one (1) hour and (15) minutes ahead of another Model A with 3:78 gears; and, with seventy-five (75) minutes less at 1,900 RPM's = approximately 142,500 RPM's less in a day, and after approximately 1,400 miles in a (7) day week, almost a whopping one (1) million RPM's less in a week.) ........ Engine wear ????????????????????????(Gas mileage ?)

Also have a B distributor and B carburetor; hence, I never adjust the spark handle and/or GAV, plus have no extra shift handle to get busy with changing gears.

Because of lots of heavy industry in our rural area, all highways take a brutal beating; so 50 mph with new Stipe shocks and radial tires in a Model A appears a good maximum in our particular immediate area.

Might add, for today's faster moving highway "Life Safety", both radial tires and Logo Lite LED headlights, and LED stop and tail lights are in my opinion, a far more important monetary investment than Model A gear changes.

Just me.

[Mitch]

If you are looking to take the 4 speed O/D route, Dave Delume's F-150 kits are first class and worth every penny. He is a VFF member old victoria so just PM him for more info.

[old victoria]

thanks mitch as posted on the modified just finished #189 the full syncro , overdrive and no cutting of your A . also do 1935 1939 v8 .