Planetary overdrive

[Lexveen]

Driving on a road where 50mph is allowed, which is the case on almost all the roads connecting villages, is not very convenient. In no time you collect quite a lot of vehicles behind you and when they start overtaking, it can be quite frightening. So I think of some kind of overdrive to be able to drive 45-50mph without overrevving the engine.
Did anyone try to integrate the Laycock de Normanville overdrive? This quite compact device reduces the rpm by 22% and is very common in older Volvo’s and a lot of British cars. It works with a planetary reduction, so you keep in style. I have some Austin-Healeys and all of them are equipped wit such an overdrive. It works with a built-in hydraulic pump and actuator that is powered by a electric solenoid. These units shift very smoothly. There is no freewheel so the brake in the gearbox keeps functioning.

[TXGOAT2]

I'd think the unit itself would be excellent, but adapting it to the enclosed Ford driveline would be a challenge. Aside from the issues of adapting to fit, you don't want to shorten the drive shaft too much, so overall length of the unit and adapters needs to be considered. My car will run all day at 45 MPH, and it has a stock driveline with no auxiliary. The engine is near-stock, with a performance cam. The engine has a stock crankshaft, aluminum pistons, Texas T oiler, and it has been balanced. It's capable of higher speeds, but I limit speed to 45 to 48 MPH in the interest of longevity. It's very happy at 42-44 MPH. I've run this car over 17,000 miles with no mechanical issues. For what an overdrive installation would cost, you might do as well to install a counterbalanced crankshaft and balance the rotating assembly. It would be a lot easier to install a KC Warford than to adapt the Laycock. I'd love to have one in my car. A KC auxiliary and a Pruss cylinder head would would probably allow me to run in the 50 to 55 MPH range. Adding a counterbalanced crankshaft to that would probably allow speeds around 60 MPH.

[TXGOAT2]

Remember that the Ford driveshaft and housing are part of the car's suspension system, as is the engine's mounting arrangement.
The Ford engine and rear axle can also produce significant torsional vibration and harmonics at certain speeds, which might be an issue for a planetary gear set.

[Mark Gregush]

A friend has one of the Laycock units installed. The conversion was done by someone down in California, I do not have any details and he has not got the car on the road to report how well it works. Not sure if those guys are even still doing the conversion.
It is going behind a not your normal standard overhead engine (T) with disk brakes but that is all I can say at this point about the project.
A number of guys have installed one in their Model A's.
With the steering and braking of a Model T, don't know if I would want to be driving at those speeds for anymore then maybe short burst. Depending on what you have done with your engine, wonder if 22% would be on the steep side? I will let someone else chime in on that front.

[Craig Leach]

Hi Lex,
My SIL has one built into the drive shaft on her touring car she loves it. I have seen several T,s set up with open drivelines using the Timken
tapered bearing pinion setup it should not be too difficult. I don't think that T radius rods are strong enough. Maybe model A radius rods would
be better?
Craig.

[Norman Kling]

I have never been in your part of the world, so cannot comment on the terrain, but if you have hills, the car will go up hills better the way Henry built it. His later car also built quit similar to the T but having a three speed transmission and more powerful engine, the Model A could drive anywhere you want and maintain the speed you would like. The Model T would need some major modifications to the engine to drive 50 mph constantly. and if you do get that fast, need some better brakes. I don't know how your roads are, but we have areas where you can pull over to let others pass from time to time.
If the land is quite level where you will be driving, you could also try a higher geared rear axle.
Norm

[TXGOAT2]

For a T running above 40 MPH, I'd want wire wheels with balloon tires and add double acting-shocks at all 4 corners. I don't know if the 21" radial tires made for Model As will fit Model T wire wheels, but if they will fit correctly, I'd think they'd be a good idea for a fast T. A fast T driven in traffic ought to have reliable brakes on the rear wheels. You'd want 30 to 35 HP to have some reserve power at higher speeds. Going to an open driveline with real brakes would require major modifications, and you'd probably be better off to build or buy a complete running gear with 4 wheel brakes, a real steering box, boxed rails, and so forth. It would be instructive to crawl under a stock T and look at the way it's built and then do the same with a Model A.

[speedytinc]

I & many others can cruise all day, comfortably @ 50-55 With 3-1 gears in a ruxtell.
You still need a strong motor to pull with an overdrive.

Building up a Laycock seems like a lot of unnecessary work to meet your performance goals. IMHO.

[Humblej]

I have no experience or knowledge of installing or driving with a planetary overdrive, but driving 45-50 mph in a model T with Model T steering and brakes is not something I would want to do.

[Chris Barker]

I have a Laycock OD in my Sunbeam Alpine. Indispensable in that car

But it needs 12v to power it. It takes 17A during engagement and about 3A when engaged.

And they are quite heavy. Would need support if hung off a Model T transmission.

Rootes made their gearbox output shaft the OD input with the eccentric to drive the oil pump.
And the splined propshaft fits directly into the OD output.
That would be more difficult to fit than the type shown, with flanges on both ends.

[ChrisB]

We have on of these in our 26 Touring with a Ruckstell and a 4:1 rear axle ratio.

It works really well. Our car is still 6 volt and the solenoid works just fine.

You also have a switch that disconnects the overdrive if you go into reverse - apparently they don't like going backwards.

This is from a post in the old forums:
https://www.mtfca.com/discus/messages/2 ... 1182823441

That is a Laycock overdrive from a Volvo most likely. Some were installed in Jags and MGs. They are done by "Overdrives by Mick & Rich" out of the Bakersfield area. This is a slick unit. They shift at the touch of a button- full throttle up or down shifts. Feels like an automatic shifting. Also, they have a ratio that allows you to "split" the Ruckstell, providing a gear between Ruckstell and high. I have a couple of them, at about $1200 a pop. Bad news: 18 to 24 month waiting list. Well worth the wait.
Fordially, Erik

Use this to search for more posts about them.

Paste the following into your search engine:
laycock overdrive site:www.mtfca.com

[Mark Gregush]

Chris, thanks for posting the name. As close to the rearend as the one I was reinstalling on a shortened drive shaft (was originally made for a stretched T frame), I really don't think it would much more unspring weight then say one of the cast iron over drives bolted to the rear end.

[TXGOAT2]

I'd want it up-front.

[Lexveen]

Our T is a 1926, has a Sherman style HC head, a Scat cranck, su carburetor, double exhaust manifold and as a result is quite strong. It also has a Ruckstell with 3.25 ratio, Rocky’s and 12V. So I think much of the conditions for an overdrive are good. Roads in the western part of Holland are flat. The main goal is to take advantage of the strong engine to drive 45-50 with lower rpm. And when the wind is strong or going up a hill, you shift to 1:1 reduction in a second.
My main question is how to integrate it in the driveline. I thought of integrating it in the torque tube/drive shaft as close as possible to the universal joint. But I don’y know if the overdrive likes the vibration and movement of the rearaxle…?

[CamMan]

Laycock overdrives are quite popular in Model As and early V8s. Installation issues are the same for a T. I put one in my ABC speedster many years ago and love it. I like it because it is small and unobtrusive. Unless you crawl under the car the only visible sign is the small toggle switch to activate it. Mine was built by someone else but there used to be some folks in California that would do the conversion (try searching "Laycock" at Ford Barn). They come in different ratios depending on the planetary gearset used. I believe the J-type used in the later Volvos were 25%. I used to see them on ebay for $100. Of course adapting one to a Model T is considerably more expense.

[Lexveen]

This looks very good. So it does not suffer from the movement and vibration? Was there a reason to but it backwards so much? I would say it could be closer to the gearbox.

[George House]

This’ll make your Model T travel at the speed of light - but then your headlights won’t work….;o(

[Susanne]

With a T, that's closer to the speed of dark!

[DLodge]

I have never been in your part of the world, so cannot comment on the terrain, but if you have hills, the car will go up hills better the way Henry built it.

Norm, I lived in the Netherlands for 9-1/2 years. The highest point in the entire country is 1,056 feet above sea level. Hills aren't really a problem there.

Lex, thanks for the reminder. I had an Austin-Healey 3000 when I was in the Air Force and had forgotten it had an overdrive. I really liked the car, but I was younger them and getting in and out of it was easier. I could probably still get in okay, but getting out would be a problem.