Model A flywheeel lightened

[WHN]

My personal view on everything that has to do with a Model A is the more stock the better.

With the exception of oil and tires.

Henry’s design has lasted 90 years. A stock, well maintained or correctly restored car, will out last all of us. Keep it simple stupid. Enjoy.

[George Miller]

Originally Posted by BRENT in 10-uh-C

Does the weight really matter with regard to vibration? If the weight of the flywheel is 30 lbs, 40 lbs, 60 lbs, or 100 lbs, if it is correctly balanced, why would there be a vibration?

I agree he had other problems. The first Burlington crank I used had the flywheel flange running out .005 that will make it vibrate. I ended up turning the flywheel on the crank. Not what I wanted but the guy did not want to send it back. That engine is still running strong, not sure how many miles but he drives it a lot.
I still would not fix any of my engines that way, or any one else's .

[updraught]

Originally Posted by BRENT in 10-uh-C

Does the weight really matter with regard to vibration?

Not as far as I know...

From what I have read of your previous posts you are concerned about a lack of momentum on cornering and having to change down gear. That sounds more like a symptom of a light fly wheel to me. At what weight that happens in a Model A I don't know.

[BRENT in 10-uh-C]

Originally Posted by updraught

Not as far as I know...

From what I have read of your previous posts you are concerned about a lack of momentum on cornering and having to change down gear. That sounds more like a symptom of a light fly wheel to me. At what weight that happens in a Model A I don't know.

I don't necessarily think that too Light of a flywheel causes a vibration, -but more of a driveability issue. Maybe this is where there is confusion? For example, our race cars have almost 15:1 compression and have no flywheel per se', so they do not idle smoothly however the engine does not have any noticeable vibrations.

[Kohnke Rebabbitting]

Originally Posted by SSsssteamer

I installed a model B engine into my 1929 Tudor. I used the full weighted model A flywheel on the B crankshaft and it all went together very nicely. My big bonus was with using the A flywheel, the B engine really runs vibration free. There never has been a vibration seen in the Tudor's mirrors at any speed. On our 1930 A Touring, using a lightened flywheel and the crankshaft having added counterweights, I have never driven such a terrible vibrating model A before. It was professionally built up as a "Touring motor". During the rebuild, the touring's engine/ crankshaft, and flywheel were all balanced by the well know engine re-builder too. Very disappointing. If you like a smoother running engine, I advise against using a lightened flywheel.

A lightened flywheel will not cause vibration, there is something , out of many possible things that was missed, that caused it.

Herm.

[Kohnke Rebabbitting]

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Originally Posted by Terry, NJ

Reading Brent's post makes me think of of my own efforts to lighten an A flywheel. I believe in a bunch of "Slight" modifications. I don't like radical changes to anything. The Mod. A flywheel weighs 63 pounds, there is plenty of weight that can be removed without substantially changing the weight to engine power ratio. How much more power is drawn off by turning a 63 lbs wheel compared to say a 53 lb wheel? Moreover, the weight that is removed is mostly at the farthest part of the wheel from center where it has the most effect. We lighten pistons and rods to harness more power from the explosions above. Why shouldn't we lighten the the heaviest link in that chain?
There is one more consideration. The weight on the rear main bearing. While most would agree that rear main is pretty substantial and can stand up to the weight of the flywheel. Most would probably agree that 10 or 12 lbs less on it would be a good thing. But I believe that the flywheel should be accurately balanced and that's with out the clutch. Ok if you balance the whole spinning mass and then you replace part of that mass (replace the clutch) is the flywheel still balanced?
Terry

The Model A flywheels we have lightened run from 69, to 70 pounds. We take two Dimensions off, one inside, and one out side. The total is about a consistent 25 pounds .

Herm.

[Terry, NJ]

Herm, If you're using that drawing that's around on the internet, like I am, then the bulk of the stock removed is on the outer radius of the flywheel. Both inside and outside. I don't know how to calculate the effect, but it's obvious that the more "meat" removed from the outer surface, the greater the effect. An analogy would be putting a pipe on a wrench to loosen a stuck bolt. I don't believe I've seen a 70 lb flywheel. Mine have all run around 63 Lb. And IO agree, a lighter flywheel is not a cause of vibration! I think if a Flywheel has a vibration because it was lightened, then someone forgot to balance it afterwards. Balancing it is critical for the life of the rear main. But if lightening flywheels was so detrimental, why did Henry (or Edsel) lighten the model B's to 50 lbs? And where were the reports of excessesive vibration?
Terry

Originally Posted by Kohnke Rebabbitting

The Model A flywheels we have lightened run from 69, to 70 pounds. We take two Dimensions off, one inside, and one out side. The total is about a consistent 25 pounds .

Herm.

[Benson]

If you use the Secrets of Speed drawing posted on Internet be aware that there were two versions.

THe first one is wrong and has an incorrect dimension and will possibly create a dangerous and weakened flywheel.

[Charlie Stephens]

Originally Posted by BRENT in 10-uh-C

I have had two failures of the Burlington crankshafts. I don't have positive vibes about those cranks nor of either of the owners. It cost me a lot of money to correct their malfunctions. Not sure how this applies to this thread though.

Brent,

How about a little more info? I thought the Burlington crank sounded interesting. Were you racing or driving reasonably?


Charlie Stephens

[BRENT in 10-uh-C]

Originally Posted by Charlie Stephens

Brent,

How about a little more info? I thought the Burlington crank sounded interesting. Were you racing or driving reasonably?


Charlie Stephens

Charlie, this was discussed here on the forum several years ago. It has left a pretty bad taste in my mouth but the bottom line for me is that for a few hundred dollars more, I can purchase a US manufactured one that is constructed by a well-established and respected company that specializes in building quality crankshafts for motorsports applications, --or I can purchase one that is manufactured 100% by an off-shore company using 100% Chinese materials, and by one of many manufacturers who have pretty much proven they have poor Q/C standards & methods in manufacturing.

If for no other reason, compare the warranties between the two manufacturers. One basically states they promise it will be built to Ford's original specifications however outside of that, there is no warranty. If the manufacturer has that much confidence (--or lack thereof) in their product where they will not stand behind it, what should that say to you or I as the consumer?


.

[daren007]

I wish someone could answer that question. I have a "B" engine with counterweighted crankshaft that has been balanced as well as "A" flywheel and clutch that still shook really bad at a higher idle. A lightened flywheel with V8 clutch did not change anything. Please do not tell me this is a normal "A" vibration as Ford would not ship them in this condition and the public would have refused to buy them.

[Charlie Stephens]

Originally Posted by BRENT in 10-uh-C

Charlie, this was discussed here on the forum several years ago. It has left a pretty bad taste in my mouth but the bottom line for me is that for a few hundred dollars more, I can purchase a US manufactured one that is constructed by a well-established and respected company that specializes in building quality crankshafts for motorsports applications, --or I can purchase one that is manufactured 100% by an off-shore company using 100% Chinese materials, and by one of many manufacturers who have pretty much proven they have poor Q/C standards & methods in manufacturing.

If for no other reason, compare the warranties between the two manufacturers. One basically states they promise it will be built to Ford's original specifications however outside of that, there is no warranty. If the manufacturer has that much confidence (--or lack thereof) in their product where they will not stand behind it, what should that say to you or I as the consumer?


.

Brentt,

Who is the "well-established and respected company that specializes in building quality crankshafts for motorsports applications"?

Charlie Stephens

[12secvx]

I guess I will find the image for you. Look at the drawing below. It should give you the closest answer I can give

[12secvx]

Like others have said the numbers in the red box have been corrected from original. And all measurements are from center of flywheel.

[Kahuna]

When I was a kid of 15, I bought an engine from a guy who was changing to a Flathead V8. The engine Vibrated quite badly at anything above an idle.
The engine cost me $110.00. My Dad loaned me 25 dollars to help me buy it
It was a B block with a Harmon & Collins cam, had adjustable lifters
Bored to 4"
Had a Counter balanced crank
Had a Burns dual intake manifold with 2 97's
Had 2 exhaust manifolds that were cut in front & welded to create dual exhaust
Had a Winfield Aluminum head
Had a B distributor
Had a 12# Aluminum flywheel. The flywheel had a steel plate that was screwed to the aluminum flywheel. This was the cause of the vibration, as the threaded holes in the flywheel were badly worn. My Dad took the flywheel to work and had some steel inserts placed in the flywheel to correct the problem for me, and then had the flywheel re balanced with the pressure plate.
As has been said by others, the only issue was low speed driveability with the light flywheel.
Jim

[daren007]

Hmmmm. I thought I already posted this. My "B" engine has had the crankshaft with model "A" flywheel and pressure plate balanced but still shakes real bad at high idle. We tried a lightened flywheel and V8 clutch with no change. This is not a normal model "A vibration. Henry would not let the cars out of the factory like this nor would the public buy them.

[Terry, NJ]

I hadn't thought of this before, but a high lobed cam will make a engine vibrate considerably, or so I 'm told. I have no experience with high lift/lobe cams so you'll have to discuss it with someone more knowlegeable.
Terry

[Jungle Jim]

Guys,

A flywheel is an energy storage device. It basically damps out the power pulses as the respective cylinder fire. Less mass/moment of inertia results in less damping effect.

Jim

[updraught]

Originally Posted by 12secvx

I guess I will find the image for you. Look at the drawing below. It should give you the closest answer I can give

Thanks. This might be a bit more readable.
https://www.jalopyjournal.com/forum/...s-jpg.3308173/

Combined with this, the differences between A and B flywheels can be seen.
http://www.fordgarage.com/pages/flywheels.htm

[Gene F]

Terry, I have only known of (heard of) the flange on the back of the crankshaft shearing off 2 times. I have head my A since 1994. Out of what 5,000,000 A's I'd say odds are good that if you drive the car normally you will be ok.