V8 Clutch vs. Standard

Al 29Tudor

Al 29Tudor

Well-known member
Is using a V8 clutch in a model A really worth it? And is it a very straight forward installation? Many changes are stated as "easy" then all the little problems pop up during the installation. Are adapters required as well as a new flywheel? Thanks for your help. I really would like to have advice from someone who has gone through the installation and the benefits or problems from the V8 clutch.
I appreciate your help on this.
Al
 
First you have to machine the flywheel to make room for the V8 pressure plate. You have to drill and tap for the mounting bolts which means you have to indicate the pressure plate to get it centered. You could do this on the engine with the engine vertical in a stand or use a turn table with the flywheel mounted on it.

You also need to balance the pressure plate which is best done mounted on the flywheel to be used after the flywheel is balanced. Balance the pressure plate separately (drill holes in the plate). Match mark the pressure plate to the flywheel.

The easiest thing to do is to buy a lightened flywheel that is already drilled for the mounting holes from one of the vendors.

Use a dial indicator mounted on the flywheel to make sure the bell housing is true and then mount the dial indicator on the bell housing to make sure the flywheel is true. The spec on the flywheel is within 0.005 inch total indicated runout (TIR) at the maximum diameter of the surface where the clutch friction disk will mount.

The V8 clutch is really nice and smooth. The lightened flywheel aids acceleration, especially in first gear, but it adds a little torsional vibration at lower RPM.
 
I've run one for over 30 years (about to re-do it with a new engine) but the clutch is as smooth today as it was the day I put it in. Really runs great and like "nkaminar" says it is really smooth.
 
Look in the vendor books where they post a picture of the A pressure plate and the V8 pressure plate. Open the inspection plate under the floor board in front of the shift tower and you will be able to see the pressure plate in your car.
 
Katy
You can't tell what pressure plate unless you take the floor boards up and the cover for greasing your throw-out bearing. If you look down into the clutch area you can see (if your familiar with how the two pressure plates look) you would be able to tell, but other than that you can't tell.
 
Typical V-8 pressure plate has three release fingers readily visible through the clutch housing cover. The Model A pressure plates have multiple release fingers much like a diaphram clutch. Probably not worth changing to a V-8 clutch alone unless being done in conjunction with an engine change/rebuid IMHO. Other than the heavily modified flywheel, no special parts are needed and the mod is pretty much a bolt on.
 
To be able to install the 9-inch Long type clutch, all of the rim has to be whittled off to get a surface that is flat all the way across. A good bit of weight is removed. This reduces inertial torque build up but allows for faster rpm build up. There is a trade off there but it doesn't affect the lighter body cars all that much. The trucks would be adversely affected since the average model A engine has less horse power than the later Ford engines.

I suggest getting an old original 9-inch with flyweights and adjustable fingers and have it rebuilt. A lot of new ones don't have these features.
 
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I installed a V8 clutch almost 3 years ago as part of an engine rebuild. The pressure plate and modified flywheel came balanced from the rebuilder with the engine; it uses the standard Model A clutch disk.

It is very smooth, but the Model A clutch was pretty smooth also. I’m honestly not sure I can tell a difference. For my present restoration project (‘29 Sport. coupe), I’ve installed the standard Model A clutch assembly.

Jim
 
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A properly adjusted A pressure plate balanced with the flywheel ( if you can find a B flywheel it’s 10lbs lighter than an A) is just as good as a V8 clutch without the investment. Rotor wrench mentions the finger counterweights, which provide a centrifugal assist on engagement, making it easier to operate.. minutely in my opinion.
 
I have been running a v8 for about 6 years and would never go back. I installed mine when I had the engine out.

1: It is much easier to depress the clutch.

2: In first gear the car spools up much quicker because the engine doesn't have to cart around that extra 30 lbs of flywheel.
 
I have 2 cars with a V8 clutch. I installed the first because I could, then my wife drove it. The lighter pedal pressure makes it easier for her to drive in the city and I'm all for our women enjoying these cars like we guys do. In fact, I have just spent 3 solid days working on a Model A belonging to a widowed friend who loves driving (now) her '29 Roadster. We are leaving on Friday for a 1,000 miles rally and the National meet is coming up later in the year.
In short, IMO a V8 clutch has other advantages.
 
I had the V-8 clutch, pressure plate, and lightened flywheel done after I bought my restored Model A 16 years ago and thoroughly enjoy it. The clutch pressure is significantly reduced; I drove a friends Model A with the standard clutch and could not get over how much less pressure is needed….and very smooth too.
 
I upgraded to V8 clutch in our 31 Coupe, really could not tell any difference when driving it.....
(your results may vary)
 
The flyweights actually apply more pressure to the disc the higher the rpm gets. Where they assist is at low rpm or when pulling away from a stop. The lower spring pressure makes clutch disengagement easier and provides a cushier engagement that reduces wear and tear of transmission & drive line components. The Long clutch design was a very good one in that era. It was used for many years before the modern diaphragm types were developed.
 
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