I am going to pull the Ruckstell from my speedster to fit it to my Duncan and Fraser roadster. Presently it has a 3:1 crown wheel and pinion gearset, which is fine for go in a light car, but results in abysmal braking. I do not want this for my roadster so was contemplating mating one of Chaffin's 12 tooth pinion gears to the 39 tooth crownwheel presently installed.
This will give me a 3.25:1 ratio, a bit of a kick along, without going over the top. What has been your experience? Are there any pitfalls in the actual installation?
The car will have some engine improvements to provide extra power, and I have a set of new small drum Rocky Mntn brakes to fit.
Allan from down under.
I am also interested in this subject. Thank you for bringing it up!
Allan - How much does your Duncan and Fraser Roadster weigh? That'll make a big difference. I'd say if the D & F Roadster weighs less than 1500 pounds, put the 3 to 1 in it. If more than 1500 pounds, then the 3.25 to one might be the better choice.
Just my opinion.....
Les, I find the 3:1 ratio un sociable. When touring with other Ts, I have to drive faster to keep the car running sweetly. Touring with standard cars means the speedster is lugging at lower revs than is optimal. Besides which, the brakes are baaad, the car being pushed along by the tall diff. Around town I found myself staying in Ruckstell low and Ford high just to be safe.
Looks like it is a good thing I did not hold my breath waiting for a response.
Allan from down under.
For some of us, it is a thing called work that keeps us from reading even half the threads on the forum. At least it is that way for me. I would highly recommend you read the documented study on the Tulsa web site about horse power, torque, etc. It does a great job of explaining what the different changes mean in the cars drivability see: http://mtfctulsa.com/Tech/power_and_torque.htm and if you are not into details skip the part about “Are the Calculations Valid” the short answer is “Yes – they are.”
For the brake situation – auxiliary brakes could solve the issue regardless of which rear axle ratio you choose.
Good luck with your decision and please let us know how it works out.
Hap l9l5 cut off
It depends a lot on how flat the terrain is where you plan to drive the car. the 3.0 will give you higher speed with less engine speed on level ground, but it is harder on the low band when you start from a stop. Going up the slightest grade, you will need to start out in Ruckstell. Also when in a tour with other Model T's if you are going uphill, you will need to keep up your RPM of the engine or you will need to shift down. At the same grade the standard ratio will pull in high at about 25 MPH, you will need to use Ruckstell because your engine would run better at 30 MPH with the ratio. If you have Ruckstell you should have auxiliary brakes anyway. If you have a hard time stopping your car, you can use Ruckstell or low pedal at the same time you apply the brake. 3.25 would be better than 3.0.
Like you, I am interested in peoples experience with the 3:25-1 ratio. I believe originally Ruckstell offered a 40 tooth crown (which is different from the Ford 40 tooth crown). I believe you can use the 12 tooth pinion with it to achieve a ratio of 3.33-1. Of course finding this crown in good condition is not easy. A couple of years ago I acquired a very nice original Ruckstell stamped 13-40 gear set (3.07-1 ratio).
Some years ago I installed 3-1 gears in both my '13 touring and my '27 roadster. I was totally disgusted with the "drivability" factor of both cars and quite quickly converted them back to 3.63-1.
I still have one of the 3-1 gear sets sitting there and have bought one of the 12 tooth pinions. I am trying to decide whether to go with the 12-39 (3.25-1) or the 12-40 (3.33-1).
I live at a elevation approaching 4.000 ft in a somewhat hilly country. My '27 is a totally stock higher mileage, but strong running car with a Ruckstell. My '13 is a 13 year old restoration with Stromberg OF, high compression pistons, a mild camshaft and a Universal brand 2 speed in the driveshaft. And a Truefire ignition powered by the engine's magneto. The Universal 2 speed is a bit of a drawback as it is 2-1 ratio (not nearly as nice as a Ruckstell), but it allows me to run the stock '13 rear axle.
So I am really interested in hearing from others who have run either the 3:25-1 or 3:33-1 ratios.
Please seriously consider accessory brakes. Ideally of course front wheel in my humble opinion!!!!
We already have a 1920 roadster with 3:1 gearing and a Moore underdrive, which is also 2:1 incidentally. It is year model correct with a straight through NH & has at different times sported an original cam and later a Chaffin regrind. This car was always fleet footed on a flat road, but not capable in hills or high wind and so the brakes were a bit hard too.
You'll have experienced the arkwardness of the ratio in your own car. We always start in low range, ford low to ford high and then a big shift straight to high high. The Moore will shift quickly with a foot throttle and so dusting off model A's from a standing start is easy.
Those running Ruxtells walk away from us when climbing hills, until the terrain is steep enough to warrant them going for Ford low... then of course you have the advantage again.
What I will say is that installing a Zed head did nothing short of transforming it. I have been balked at the bottom of a pretty fair hill and had to reach for low range... I was amazed that having lost the initiative, the extra compression allowed me to pull out and shift to high on the way past.
The car has done thousands of miles, (think NYC to LA, and return a couple times or more) but is languishing sadly. I fitted the Zed head, did about 1900miles in 10 days and within an hour of home the crank let go It's next on the list...
How have you been going with front brake projects?
Sorry to hear of your broken crank.
It is "my opinion" that 3-1 gears are really hard on T cranks!!
I believe that lugging the T engine is about the worst thing you can do!! And with 3-1 gears in a stock bodied car you will often be lugging. I don't believe that a few extra revs are nearly as bad. Now this is just my opinion!!
Well I am on version 3. I have slowed down on the brakes to bring the Ross steering box forward, as I believe that front brakes should only be used with a improvement in the steering box OR front axle geometry (which I did on my '27 roadster). I hope by the end of the calender year to have the Ross boxes done and by spring to have a one of version 2 and one of version 3 in test mode.
It seems no one is running a 12 tooth pinion. SIGH!!
Les, I have a 12 tooth in the Ruckstell sitting in the garage waiting to go under my 26. I've still got to fit the Rocky Mountains on it and then replace the stock rear on the Coupe. I'm sorry it isn't to the point of testing yet! I expect that with a strong engine, it should perform well but time will tell. Noel
The late Lear Simpson from El Cajon, Calif, ran 3.25 in all his Ts. I don't think he used underdrives. I believe he was a member of the SoCalif T club, which traveled a lot.
Hi Alan / Guys,
3:1 or 3.25? Hmmm...what's wrong with standard gearing? If you only use roads that are flat and never drive in stop-start traffic then 3:1 or 3.25 might be okay; but even then, I fail to see significant benefits compared to standard gearing unless we're talking a racer or serious speedster.
For those ratios to work in hills then a very light car with a very very strong modified engine is needed.
If you really must have 3:1 or 3.25 you can do so by adding a KC Warford to standard gearing or a 10-tooth. Although one needs to consider the effects of the added weight of the Warford and whether having a rarely used overdrive is worth the $3000+ price tag.
My touring with Z head, Stipe, balanced engine and standard gearing (without a Warford or Ruxstell) can sit on 40MPH all day stress free, even when carrying 3 adult passengers. A hill has to be quite steep to force me into Ford-low.
26HP with 3:1 or 3.25 is not a good mix.
You may very well be right. We are just hoping to hear from someone who has tried 3.25 (or possibly 3.33). Alan, Anthony and I have tried 3.0 and have reported our findings. I have for almost 40 years run 3.63. Doesn't mean I'm not interested in learning, but I would prefer it wasn't ALWAYS from my own experiences!!
I feel compelled to chime in here as you want everyones opinion or experience. First off, I think each of us has to do what's comfortable for you. I like to go comfortably fast without overworking my engine and have had a lot of success. In my Dreyer's ice cream truck, light delivery basically car chassis, total weight around 2100 pounds, dead stock engine other than aluminum pistons. Before I restored it (1963) I put 13/40 gears in the Ruckstell and was not satisfied engine working to hard for me, on the open road. So when I restored it in 1965 I put in 13/39 gears, drove it 42 years that way and loved every minute of it. Among the many trips, drove it from San Francisco area to the Catalina tour (1969 I think, see cover Vintage Ford Volume 4 #4) with our 3 daughters in the back and on our return trip drove into Yosemite National park, stayed for a few days and then on home. In the 42 years I never had the engine apart or the Ruckstell. My race car #4 has 13/39s in the Ruckstell and a Muncie with overdrive, very tall final gear, and I love it. To reduce the brakes problem I not only have outside brakes, (but only hooked up to the emergency brake lever)when I see the need to stop I down shift the Ruckstell. In the ice cream truck downshift sometimes at 30 MPH or so depending on the situation (panic or not) in the race car sometimes as much as 45 MPH or so, not normally, usually when I need to, when historic racing.