View Full Version : Transmission Conversion Time - I think...

04-09-2014, 09:00 PM

I have been doing some reading and trying to find the right thread that can help me determine if it's worth the trouble as well as get some guidance on installing a C4 transmission.

I have a 64 convertible running a 170cid with a fordomatic. I want to get better gas milage as well as make it easier to get on the highway.

I am not sure if the conversion is possible as I have yet to find an article that covers this swap. I have read that there is a difference in bell housings as well as having to shorten the driveshaft, get a different transmission mount and installing a different **** plate. In either case, I would like to think this should be a rather simple conversion yet I haven't come across any reliable guidance, so I thought I would ask the only place where true advice lives..


04-09-2014, 10:29 PM
I won't get into bellhousings here. I'll leave that to someone else.

Let's compare the Ford-o to the C4. The Ford-o is a 2 speed with a final drive ratio of 1:1. The C4 is a 3 speed with a final drive ratio of 1:1. So what you'll end up with is the same high gear ratio with a really low 1st gear. It will be great for quick launches but won't help with the gas.

Now let's talk C4 + new rear end. If you change to a C4 "AND" change the rear end gears from the 3.5:1 you have now to a 2.79:1 ratio, you'll have decent highway manners and the first gear will be very close to the Ford-o 1st with the 3.5:1 rear.

04-10-2014, 04:39 AM
If you end up with a driveline issue, the guys over in SoDo at Drivelines NW can do a good job for reasonable money, and TCI can fix you up with a bell housing, if you don't want to sort out a used one. Alignment of the driveshaft is going to matter, if you don't want the harmonics making you crazy as you roll down the road.

04-10-2014, 07:42 PM
... if it's worth the trouble as well as get some guidance on installing a C4 transmission.

The first two guys provided some insight into the second part of the question on how to install a C4. It can be done, people have done it, and you can start at a little lower gear and it will run at about a 15% lower rpm in high gear. But ..... you will have to change the transmission, rear end, bell housing, etc.

Is it worth the trouble? That is the real question. How often do you drive on the interstate? How fast do you want to drive on the interstate? If you want to drive fast, maybe you could get an automatic with overdrive (four speed) rather than a three-speed C-4. Also consider that your car has four-wheel drum brakes. They are fine at lower speeds, but you might want to upgrade to disc brakes if you are driving at higher speeds.

If you stay with your Ford-O-Matic you can still drive on the interstate, but just stay in the right lane and drive 60 mph and let everyone else pass you. I have a friend who drives his completely original in-line eight 1931 Nash on the interstate. Everyone that passes him waves and gives him a thumbs up. They don't get mad. 60 mph was considered the "normal" highway speed when your Falcon was new and that is the about the speed at which it runs most efficiently. That is why 55 mph was chosen as the national speed limit from 1974 to 1987. Your Falcon should be able to run all day long at 60 mph. Plus, the two-speed Ford-O-Matic is (in my minority opinion) .... way cool. It is a one shift wonder and is original to your car. There are not many left and that "obsolete" transmission can be considered to contribute in a large measure to the charm of your fifty year old car. This is what the original literature had to say about the Ford-O-Matic:

"Fordomatic Drive features simplified design, light-weight cast aluminum construction, vacuum-controlled throttle valve for smoothness, minimum servicing. Torque converter in combination with compound planetary gear set. Gear ratios: Low 1.82, Direct 1.00, Reverse 1.73, Converter (Stall) 2.4. In “D": range gives brisk, smooth starts in low. Effective engine braking in “L” position. Air-cooled with 144 Six. Air and liquid cooled with 170. Selector lever and quadrant on steering column, sequence P-R-N-D-L."



04-10-2014, 09:59 PM
thanks for all the insight guys.

First I should say that restoring the car took three years and it was a full rotisserie restoration that involved a donor car and a lot of fabrication. I drive the car just about every other weekend around town and since having it completed have put about 400 miles on it. She is a 170, fordomatic, 3 core radiator, electric fan, petronix conversion points, front disc brakes including power booster, new gas tank and lines, new brake lines, new interior, front power windows, full headers, dual exhaust and the engine and transmission are both original to the car even though they were gone through at least once before I got the car.

I have built up enough confidence in driving the car locally that I don't think about breaking down any more, but, I have not been on the freeway yet, hence why I thought getting a C4 would benefit my future highway driving to car shows. Thanks to the new info I have just learned, I am convinced I will refrain from altering my 64 beauty queen. Once again, thank you guys for your feedback, knowledge and advise.

04-12-2014, 07:08 AM
I drive the car just about every other weekend around town and since having it completed have put about 400 miles on it.

Your car wants you to take it back on the road and start adding mileage to the odometer! The only way to find out if everything is fixed is to try it out. If something quits, figure out why it quit, and then fix it and drive the car some more.

I drove a 1963 Falcon station wagon with a 170 and a Ford-O-Matic while I was in high school (1978). I never noticed a problem with that combination. I had a 1963 two-door sedan with a 170 and two-speed in 1985 while going to college. I drove that car everywhere, and again, I never perceived any problem as far as not having adequate speed or acceleration. (But, the national speed limit was only 55 mph at the time.)

Here is some performance data that I copied from a book called "Falcon Performance Portfolio". Compare the 0 - 60 times and 1/4 mile times and speeds for a 4-speed manual and a two-speed Ford-O-Matic in a 1963 convertible with a 170. The 4-speed is teamed with an optional 3.5:1 rear end which would allow a little quicker take off and the Ford-O-Matic is teamed with the standard 3.2:1 rear end. Even so, the performance figures for the two configurations are surprisingly close.

1963 - 170 Six Cylinder Convertible, 2,754 lbs
Top speed = 90 mph. 19 - 23.7 mpg at 65 – 70 mph.

Gear ratios for 4-speed manual for 170 Six: 3.16, 2.21, 1.41, 1
4-speed: 0 – 60 mph in 19.6 seconds and 22.7 seconds for the mile @ 64 mph with a 3.50:1 differential.

Gear ratios: 1st with initial torque converter torque multiplication (2.4 x 1.82) 4.37, 1st 1.82, 2nd 1.00.
Ford-O-Matic: 0 – 60 mph in 21.6 seconds and 22.2 seconds for the mile @ 61 mph with a 3.20:1 differential.

04-12-2014, 09:08 AM
1/4 mile in 22 seconds????????????????????????? Fuel economy?????????????

04-12-2014, 09:31 AM
1/4 mile in 22 seconds????????????????????????? Fuel economy?????????????

Yep. The 2,754 lb convertible weighed 346 lbs more than the 2,408 lb sedan and that extra weight shows up in the performance figures. A sedan with the same 170 and Ford-O-Matic will go from 0 - 60 a full six seconds quicker (with the 3.5:1 rear end). 15.2 seconds vs. 21.6 seconds. Weight really makes a difference.

1961 - 170 Six Cylinder, 2,408 lb.
3-speed: 0 – 60 mph in 14.3 seconds with a 3.20:1 differential, 21 – 25 mpg.
Ford-O-Matic: 0 – 60 mph in 15.2 seconds with a 3.50:1 differential, 19 – 23 mpg.

From a reprint of CARS magazine, April, 1963, on Page 67 of Falcon Performance Portfolio: “... a 170 cu. in. Six–powered Falcon convertible takes almost 20 seconds to reach 60 mph from a standing start, and with the English Ford four-speed at that .."

falcon cobra
04-12-2014, 09:43 AM
And that's why my 170 is on a stand in the garage, V8's are more fun to drive....jh:3g:

04-12-2014, 03:56 PM
Amen to that John. Fuel injection is nice too:rocker:

04-13-2014, 05:21 AM
And that's why my 170 is on a stand in the garage, V8's are more fun to drive....jh

This points out that making a transmission upgrade by itself (the original question) will only improve performance to a limited extent. The most direct way to raise performance is to increase engine power.

But .... the Falcon was designed to compete against the Volkswagen Beetle and not the Chevy Corvette and the original Falcon would smoke a Beetle. The Falcon had more than twice (236%) the horsepower of a Bug and still almost matched its fuel economy (83%).

1960 Beetle. 73 cubic inch flat 4, 36 hp, 1600 lbs. 36 mpg.
Top speed = 68 mph
4-speed: 0–60 mph in 32 seconds and 23.9 for the 1/4 mile @ 52 mph.
Source: Motor Trend, March 1960 See: http://books.google.com/books?id=XdZSKLcwyHEC&pg=PA57&lpg=PA57&dq=1960+volkswagen+beetle+0-60&source=bl&ots=CrW1aZwMtJ&sig=PiHIr35EcHk1N_WqZ9Eos71IJD8&hl=en&sa=X&ei=Bh9LU7_iApW_sQSB2oDICw&ved=0CHEQ6AEwCA#v=onepage&q=1960%20volkswagen%20beetle%200-60&f=false (http://books.google.com/books?id=XdZSKLcwyHEC&pg=PA57&lpg=PA57&dq=1960+volkswagen+beetle+0-60&source=bl&ots=CrW1aZwMtJ&sig=PiHIr35EcHk1N_WqZ9Eos71IJD8&hl=en&sa=X&ei=Bh9LU7_iApW_sQSB2oDICw&ved=0CHEQ6AEwCA#v=onepage&q=1960%20volkswagen%20beetle%200-60&f=false)

1960 Falcon - 144 Six Cylinder, 85 hp, 2375 lbs with a 3.10:1 differential. 30 mpg
Top speed = 87 mph.
3-speed: 0 – 60 mph in 19 seconds and 20.8 for the mile @ 64 mph.
Ford-O-Matic: 0 – 60 mph in 25.1 seconds and 23.9 for the mile @ 59 mph.