Model A flywheeel lightened

[charlesea]

How much needs to machined off an A flywheel for a B engine?
Thanks

[Charlie Stephens]

What transmission are you using? Seems like unrelated question but the Model A transmission interferes with the Model B transmission case.

Charlie Stephens

[Jim Brierley]

If using the A bell housing and trans, nothing needs to be trimmed. If using the B bell housing and trans, just a little off the outer, rear edge. B Bell housings must be used with the B trans and an A bell with the A trans, they are not interchangeable. To use an A bell on a B engine, the rear section of the B pan must be removed. If you want more info contact me at [email protected]

[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.

[Paul Bjarnason]

That is disappointing, especially since I just bought a rebuilt engine with a lightened flywheel and fully counterweighted crankshaft (everything fully balanced all the way back to the Ford V-8 clutch), amongst other goodies, at a cost of almost $10,000. I have not yet installed the "new" motor. Who was the engine re-builder and did you complain to him? If so, what did he say?

[TerryH]

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I beg to differ..... I bought my Town Sedan, over 13 years ago, with a newly rebuilt motor, but no counter balanced crankshaft. After I took delivery, I had the flywheel lightened, and also added the V-8 clutch and pressure plate. I was warned by some that the lightened flywheel would ruin the Model A....it would never run right, wouldn’t idle properly, etc. After 14,000 miles I can report that mine runs very smooth, without any undue vibration, at any normal speed, including over 60 mph on the freeway. And I can still pull away in 2nd gear, although I see no reason to do so.

[daren007]

ssssstemer I have a A with b engine and lightened flywheel with V8 clutch that I will trade you.

[BRENT in 10-uh-C]

Originally Posted by charlesea

How much needs to machined off an A flywheel for a B engine?
Thanks

About 10 pounds, but as said above, the machining of an A flywheel to mimic a B flywheel will be more money than buying a B flywheel. FWIW, several years ago I started a topic on how much is too light. I think it is worth a read.


As for the engine above that has a vibration. My instrict is that can be cured by rebalancing the flywheel, then adding the pressure plate and rebalancing.

[12secvx]

I actually just did this to my flywheel this fit into my B flywheel housing with a B transmission. I took it to get balanced and the flywheel was within a gram. But when he bolted the pressure plate on it took a lot of weight added to it to get it balanced within a gram as well. I did take a lot of weight off as well as machined it for a 9” v8 pressure plate. The complete assembly with pressure plate, disk, pilot bearing weights about 46lbs. So about 20lbs. off by my estimate from stock. I followed the flywheel lightning dimensions that they have as a cad drawing over on the HAMB.

[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

[12secvx]

I had mine balanced separately. I also made a witness mark between the flywheel and pressure plate so I made sure the pressure plate went back in the same position it was balanced in. So I guess when I get a new pressure plate it may be good to have it checked again.

[Arlyn Bieber]

I am running a 28# flywheel in my '31 slant window sedan with counter weighted crankshaft, V-8 pressure plate, 6-1 HC head, large intake valves, B carburetor and a 36% OD with 3.78 rear end. Great combination, love the way it drives. Drove from San Diego to Reno this summer. Drive it nearly everyday to Model A Garage in Ramona about 18 miles on hilly HWY 67. Yes I do have to shift out of OD on the 6% grade hill but no big deal, just shift back into OD at the top of the hill and back to 55mph speed limit. Just my thoughts and opinion. Arlyn Bieber San Diego

[31Abone]

I bot model B lightened flywheel from Stipes $250 June 2018...I ran engine on stand and seemed to run good,oil pressure was low so I'm going to pull pan and replace..will know more after i drive 32 PU.also I bot Stipes model B cam not cheap..34 engine with bal crank..Spencer

[George Miller]

Model A flywheel about 63 lbs Model B flywheel about 50 lbs.
You should not have a vibration problem with a light flywheel, some one messed up.
Most of the engines that I have done had light flywheels,never had a problem.

[updraught]

This guy should know something about balanced cranks.

https://fordbarn.com/forum/showpost....4&postcount=64

[SSsssteamer]

Originally Posted by daren007

ssssstemer I have a A with b engine and lightened flywheel with V8 clutch that I will trade you.

Daren, I recently sold my phaeton with engine balance problem. I still have the Tudor with the B engine and the A flywheel combination and it runs super smooth. I am very happy with the Tudor and I will keep it like that for long as I have it. Thank you for asking.

[Terry, NJ]

Something else occurred to me after I finished the signing and sealing of my last post. It could roughly be called torquing or twisting the crank upon stopping the engine. I see this old iron as living on borrowed time (85 + years) How long before the twisting action of a heavy flywheel is going to twist off a crankshaft. They're already flexing plenty at stopping when the energy in the flywheel wants to keep turning. We may have to make a larger diameter and heavier harmonic
balancer to equalize and minimize this twisting action. Just some random thoughts on the subject.
Terry

[BRENT in 10-uh-C]

Originally Posted by updraught

This guy should know something about balanced cranks.

https://fordbarn.com/forum/showpost....4&postcount=64

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.

[updraught]

His suggestion is 30 to 36 pounds. I don't think he would have suggested it if it created vibration.
Failures are probably to do with manufacturing.

[BRENT in 10-uh-C]

Originally Posted by updraught

His suggestion is 30 to 36 pounds. I don't think he would have suggested it if it created vibration.
Failures are probably to do with manufacturing.

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?

[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.

[Pete]

Originally Posted by 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

You were told wrong.

[Tom Wesenberg]

A radical cam can make an engine run like crap, like those rough running, loud machines at many car shows, but it shouldn't make excessive vibration. I haven't heard of any Model A cams that radical though.

[Nosetime]

Anybody have a recommendation on adjusting clutch fingers on V8 clutch on Model A? I've heard 5/8" from top of PP?

[BillLee/Chandler, TX]

Originally Posted by Nosetime

Anybody have a recommendation on adjusting clutch fingers on V8 clutch on Model A? I've heard 5/8" from top of PP?

Anxious to see an answer to this!

[Pete]

Originally Posted by Tom Wesenberg

A radical cam can make an engine run like crap, like those rough running, loud machines at many car shows, but it shouldn't make excessive vibration. I haven't heard of any Model A cams that radical though.

A long duration race cam in a model A engine can be made to idle quite smooth
at 600 to 700 rpm. Smooth enough to balance a nickel on the deck lid.
I had a flathead B engine with a 4 ported block and a 305 degree cam at the Riverside hill climb in 2002 that I drove all around LA for a week.
There are several long duration high lift cams available for A/B engines but the cost to install is WAY beyond most peoples budget. That is why you don't hear about them much.

[Mike V. Florida]

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as far as vibration, James Rogers of DreamWorks engines has stated that as of a couple of years ago he has done probably a hundred and have never had a complaint, in fact quite the opposite. He says they work great on a balanced crank or a stock one. He has found that, most of the vibration in a Model A comes from bad workmanship or flywheel housings that are broken or warped and not re-conditioned.

[BN]

There are two separate types of vibration in regard to a rotating crankshaft/flywheel/drive line. Lateral vibrations and torsional vibrations. Lateral vibrations are caused by mismatch of weights (pistons, rods, unbalanced flywheel, etc). Lateral vibrations (at 2 x RPM) are also caused by the vertical acceleration at BDC being different than that at TDC, which are inherent for a 4 cylinder in line engine. Torsional vibration is oscillatory twisting of the crankshaft and drive line. For example (when looking at the front of the crankshaft) #1 rod journal will have a different oscillatory “clocking” than #4 rod journal at a given load and RPM. You cannot usually “feel” torsional vibration, although you can sometimes hear it at a given RPM if the clutch pressure plate springs resonate with the torsional vibration. However, the crankshaft journal fillets DO “feel” the vibration in the form of oscillatory stresses (fatigue stresses) that, over time, can cause fracture. The magnitude of these oscillatory stresses is related to the firing impulses and to the natural frequency of the rotating assembly. The natural frequency (there will be several of them) will change if the flywheel weight (or more specifically the moment of inertia) is changed. It will also change if the diameter of the crankshaft journals is changed (which changes the torsional stiffness). The maximum magnitude of the oscillatory stresses will occur at a resonant condition where the firing impulse frequency is at or near a natural frequency of the rotating assembly. This is called a “Critical Speed”. On many engines, a harmonic damper is installed at the front of the crankshaft (as a part of the pulley) to reduce the oscillatory amplitudes and associated fatigue stresses at critical speeds. So, changing the flywheel weight will change the critical speed at which the maximum fatigue stresses occur and may increase or decrease their value, as well as the location they occur (#4 main journal, #3 rod journal, etc). Also, the torsional vibration characteristics for a Model A engine vs a Model B engine are different – since the Model B has larger crankshaft journals and therefore more torsional stiffness. This may be the reason Ford went to a lighter flywheel on the Model B.