Flywheel weight??
 

The original flywheel weight was about 62 pounds so how much can you lighten the flywheel and still have a smooth running engine? Here is my experience. For about the last 50,000 miles I have been running a Model A flywheel cut down to 42 pounds with excellent performance or so I thought. My car is a slant window sedan with a 33% Mitchell overdrive. My A engine has a "B" cam, "B" carburetor, counterweighted crankshaft, 6-1 Snyder head, babbitted bearings and totally balanced with standard Model A transmission. I recently rebuilt another engine but decided to use a 28 pound flywheel instead of the 42 pound just as an experiment. WOW what a difference. Much faster acceleration and no lost of power up a hill. The engine handles the 33% Mitchell with ease and I couldn't be happier with the performance. By the way my ring & pinion is a standard 9 & 34. I drive daily on hilly hwy 67 between San Diego and Ramona about 18 miles and drive at speeds 55 to 65mph. On a couple of the steeper hills I do have downshift out of overdrive but when I crest the hill it is back in overdrive. Just my experience.

Re: Flywheel weight??
 

Hey Arlyn,
Bill Stipe makes an A/B flywheel that is 23 lbs total weight. I hear that engines running this aluminum flywheel do very nicely. I'm about to try this flywheel out in the not too distant future and hope that what I've heard is accurate.

Re: Flywheel weight??
 

Shortly after I bought my Model A many years ago, I was considering using a lightened flywheel, and remember asking a supposed Model A expert and veteran about it. In a word, his comment was, don't do it, it will never run the same...won't idle, no low speed pulling power, etc. So I went ahead and had it done anyway, and never looked back. I also did the V-8 clutch and pressure plate, along with the Snyder 5.5 head, and the Mitchell OD. For me, it all works so well, and my car also cruises the southern California freeways very nicely.

Re: Flywheel weight??
 

Was the new engine exactly the same as the old engine so that the only difference in performance you noticed was due to the flywheel weight reduction? Maybe the new rebuilt engine was just more powerful.
As noted in the fordgarage link, a light flywheel does not add power to an engine. That said, a lighter flywheel has advantages in some situations.

Re: Flywheel weight??
 

Rick you will not be disappointed I have 2 1 is around 18 lbs the other not sure of lbs they help rev fast and clean
they can increase any vibration a engine has do not know why a light flywheel has this effect so get everything well balanced
2nd Loctite the pressure plate bolts I had trouble with put it down to the steel bolt in aluminium thing

Re: Flywheel weight??
 

Anyone know anything about adapting a V8 flywheel? My buddy's A engined '23 T allegedly has one fitted, but I've not checked it out. Mr Wells (HotrodPhil) remembers seeing an article dealing with modifying the starter to fit, but again I've not chased him up to dig through his magazine collection.

Many thanks

Juggs

Re: Flywheel weight??
 

Juggs
I use v8 clutches on my A/B engines there is no change to the starter motor
just use the standard starter
There are few drawing around how to machine the flywheel but 1 drawing has bad mistake so be careful
I may be able to find mine if you wish
Colin

Re: Flywheel weight??
 

Arlyn, I sell lots of lightened flywheels made in my shop and get calls for many custom weights. I have lightened flywheels down to 28# and have never had one complaint. Understand, if I do one lightened more than what taking just the recess ring off, it is at the customers request and their liability so, once done, it is yours. No complaints. I do believe these customers are happy with the extremely light flywheels and have heard positive comments from some.

Re: Flywheel weight??
 

Yes I have a couple of flywheels machined for V8 clutches, but I'm talking about actually using the V8 flywheel itself....

Re: Flywheel weight??
 

Hey Arlen, FWIW there is a thread here somewhere speaking about how I have started going the other way on flywheel weight for better drivability.

To play the Devil's Advocate, I think the key to optimum flywheel weight is the camshaft. If the engine makes strong torque down low in the RPM range, then there is no need in making quick shifts. The advantage with a heavier flywheel is I can turn a corner at slow speeds and leave the transmission in hi-gear without the need to downshift. Yes, it accelerates slower than a lighter flywheel however the extra time needed to make the 3-2 downshift, and then the 2-3 up shift on a vehicle equipped with a lighter flywheel makes it about a 'wash' in time.

The other thing is today's average Model-A drivers do not drive the car as it was intended to be operated. Today's drivers have the mindset where the vehicle needs to be revved to a high RPM in each gear. This is not how they were designed to be operated.

Re: Flywheel weight??
 

The starter drive gear must be reversed and an outboard bearing/bushing must be installed in adapter/bell housing to support starter shaft. Some V8 flywheels had a larger radius in the corner that might have to be relieved to fit the A flange but most bolt right up. Actually the starter needs more modification to get very much engagement of starter gear.

Re: Flywheel weight??
 

Brent, Not to be snarky about this, but even Henry Ford, began to see the light on lighter FWs I think all the arguments for lightening a FW hold some water. (Smooth roads, shifting etc) But I disagree about taking them down to almost 1/3 their original weight. It makes me wonder if it' ll run with so little of the original weight (moment) why do I need a flywheel at all?
Terry

Re: Flywheel weight??
 

Iffin' you got NO FLYWHEEL, where do you put the CLUTCH?????
Bill W.

Re: Flywheel weight??
 

Hey Bill,
You make me smile,eh :D !
AND, iffin you got no clutch...where do you put your clutch foot :eek: !!

Re: Flywheel weight??
 

"The original flywheel weight was about 62 pounds so how much can you lighten the flywheel and still have a smooth running engine?"

On the last 3 engines I built I used a modified 350 Chev aluminum flywheel that weighed 12 lb. I also used a rebuilt 9 inch Long type ALUMINUM clutch cover. I like the Long clutch with the centrifugal weights because it takes less pedal pressure to operate.
Two of these engines were mild street engines and they would idle smooth at 500 and lug smooth right off idle.
Light flywheels do not add horsepower but they sure add driving pleasure.

Re: Flywheel weight??
 

Andrew . we did the v8 flywheel trick some years back,1st attempt wrapped the starter armature like a banana, Next we drilled the flywheel housing & fitted a bush to support it . already having reversed the bendix unit to line it up , also then needed a opposite wound bendix spring, This was on an A block with an isuzuzu head cut in halfe ,streched two inches ( hence the extra zu) via a home made adapter plate etc etc , fired it up but got too excited & forgot to bleed air from head & cooked the head gasket ,It had potential ?? Still have in the corner , ??one day when the salt hardnens in the brain , I have a couple of stipe alloy flywheels for next projects , very nice job , picked up one at last Chickasha swap,

Re: Flywheel weight??
 

When I was a kid, I had a Weber aluminum flywheel with a steel plate and steel ring gear. It weighed 12 lbs. The clutch cover/pressure plate added more. The engine ran great.
The engine was 213 cu in, Harry Weber camshaft, Burns dual manifold with 2 81's and split exhaust manifolds.
Great memories

Re: Flywheel weight??
 

Brent....I agree with almost everything you say, but not with going around corners in high gear. Even Marco has commented that he would never do that....we know it is possible to do it, but why? The acceleration from that point is terrible, and downshifting to 2nd is simple once one learns how to properly do it. To me, that is more of a stunt, rather then good practice.

Re: Flywheel weight??
 

If it weren't for my braces, I could cruise with it in my MOUTH & if I rigged up an IN & OUT, I could be a race car pilot!
A friend had a spare motor, without a flywheel, sitting in a "box" made of 2 X 12's & cut a crank hole in it. Occasionally, he would crank it & let it run a few seconds at a fast idle, to keep it freed up & oiled well.:)
Bill W.

Re: Flywheel weight??
 

Where/when did Marco say that?

As for a purpose, again, it is more about a driving style. Your point is well taken when you say "...simple once one learns how to do it properly". Some weight off of a flywheel is not a bad thing however I have found that too much off is more detrimental than good. Also, as I stated above, camshaft profiles are a major player in this.