The Ford Barn

Arlyn Bieber · 10-24-2014, 11:55 PM

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.

hardtimes · 10-25-2014, 01:34 AM

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.

TerryH · 10-25-2014, 01:52 AM

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.

PC/SR · 10-25-2014, 02:15 AM

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.

colin1928 · 10-25-2014, 04:33 AM

Quote:

Originally Posted by hardtimes

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.

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

Juggler · 10-25-2014, 04:40 AM

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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

colin1928 · 10-25-2014, 05:00 AM

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

James Rogers · 10-25-2014, 06:36 AM

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.

Juggler · 10-25-2014, 08:15 AM

Quote:

Originally Posted by colin1928

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

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

BRENT in 10-uh-C · 10-25-2014, 08:49 AM

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.

just plain bill · 10-25-2014, 11:47 AM

Quote:

Originally Posted by Juggler

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

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.

Terry,NJ · 10-25-2014, 11:56 AM

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

BILL WILLIAMSON · 10-25-2014, 01:33 PM

Quote:

Originally Posted by Terry,NJ

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

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

hardtimes · 10-25-2014, 02:12 PM

Quote:

Originally Posted by BILL WILLIAMSON

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

Hey Bill,
You make me smile,eh

!
AND, iffin you got no clutch...where do you put your clutch foot

!!

Pete · 10-25-2014, 02:36 PM

"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.

quickchange · 10-25-2014, 04:12 PM

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,

Kahuna · 10-25-2014, 04:31 PM

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

TerryH · 10-25-2014, 04:57 PM

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.

BILL WILLIAMSON · 10-25-2014, 07:59 PM

Quote:

Originally Posted by hardtimes

Hey Bill,
You make me smile,eh

!
AND, iffin you got no clutch...where do you put your clutch foot

!!

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.

BRENT in 10-uh-C · 10-26-2014, 04:26 AM

Quote:

Originally Posted by TerryH

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.

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.

Terry,NJ · 10-26-2014, 07:33 AM

I think we had this discussion before, but I'll reiterate my point again. Ligthter FWs do not add HP, but they free it up and it goes to the wheels instead of being lost. If that is not clear, imagine a 126 lb FW, or a 189 lb FW. How much or the power of each stroke would be left to accelerate. Sure, it's great for a constant speed engine or application. But not in a car.
Terry

Quote:

Originally Posted by Pete

"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.

Juggler · 10-26-2014, 12:57 PM

Thanks Bill and Derek - if I find that article I'll report back

Regards

Juggs

hardtimes · 10-26-2014, 01:51 PM

Quote:

Originally Posted by Kahuna

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

Was this the V8 flywhl, and if so, how did you deal with the STARTER MODS that are talked about as necessary..back then

213 cu in..hm, sounds like pretty healthy build do you have pics ?

hardtimes · 10-26-2014, 01:58 PM

Hey TerryNJ,
'free up HP' , is the most succinct and accurate explaination, for what 'lightened wt' flywhl does, IMO. I have never seen any reasonable stmt of how lightening the flywhl ..has negative result (s), other than 'if ain't stock'.

hardtimes · 10-26-2014, 02:25 PM

Hey Arlyn,
'how much'.
Well, I think that Pete has lightened the least I've EVER seen run.
I'll show you some of what I'm working with , with wts recorded on equipment.

One thing that has not been mentioned here , other than great comment by Terry,i.e.- frees up HP, is that ALL that removed weight from flywhl/pressure plate and disc...IS REMOVED from the downward force on the rear main bearing. IMO, wt removal to get this benefit..alone..is worth the cost/effort

.

hardtimes · 10-26-2014, 02:34 PM

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Hey Colin,
Since you've used and are using TWO alum flywhls, maybe you can help me out here, as I'm going to use the one pictured below.
My question is: Are you 'staking' the ring gear onto the alum flywhl or WHAT process are you using to ensure that flywhl stays put

!
The alum flywhl that you are looking at, has new ring gear on it. This ring gear seems to move quite easily...compared to heat fit iron to iron gear. Any recommendations to avoid calamity appreciated,eh

Purdy Swoft · 10-26-2014, 03:08 PM

I remember Marco mentioning lugging around corners in high gear with full advance being a bad thing and I agree that it is. Higher gear ratios only make matters worse in such situations. I agree that driving style or skills make all of the difference. I only run 3.78 gears in mine and the lower ratio lessens the risk of lugging. Corner turns can be made in high gear if enough speed is maintained to avoid lugging. I can see no advantage for a heavy flywheel in this day and time. We don't need to creep over sand beds and rutted trails like many had to do in olden times. That said my experience is that a light flywheel will give the most noticable increase in accelleration and driveability next to a higher compression head .

10-24-2014, 11:55 PM	#1
Arlyn Bieber Senior Member Join Date: May 2010 Posts: 180	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.

10-25-2014, 01:34 AM	#2
hardtimes Senior Member Join Date: May 2010 Location: South California Posts: 6,188	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.

10-25-2014, 01:52 AM	#3
TerryH Senior Member Join Date: May 2010 Location: Fountain Valley, Calif. Posts: 937	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.

10-25-2014, 02:15 AM	#4
PC/SR Senior Member Join Date: May 2010 Location: Santa Rosa, CA Posts: 1,282	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.

10-25-2014, 04:40 AM	#6
Juggler Senior Member Join Date: Aug 2010 Location: Phoenix AZ/Bath UK Posts: 481	Re: Flywheel weight?? Sponsored Links (Register now to hide all advertisements) 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

10-25-2014, 05:00 AM	#7
colin1928 Senior Member Join Date: Mar 2013 Location: Australa Melbourne Posts: 878	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

10-25-2014, 06:36 AM	#8
James Rogers Senior Member Join Date: May 2010 Location: Asheville,NC Posts: 3,104	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. __________________ http://www.model-a-ford-4bangers.com/

10-25-2014, 08:49 AM	#10
BRENT in 10-uh-C Senior Member Join Date: May 2010 Location: Eastern Tennessee Posts: 11,550	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. __________________ . BRENT in 10-uh-C . www.model-a-ford.com ...(...Finally Updated!! ) .

10-25-2014, 11:56 AM	#12
Terry,NJ Senior Member Join Date: Nov 2013 Location: Northern Bucks Co. Pa Posts: 632	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

10-25-2014, 02:36 PM	#15
Pete BANNED Join Date: May 2010 Location: Wa. Posts: 5,423	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.

10-25-2014, 04:12 PM	#16
quickchange Senior Member Join Date: May 2010 Location: Nelson. New Zealand Posts: 2,010	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,

10-25-2014, 04:31 PM	#17
Kahuna Senior Member Join Date: May 2010 Location: NorCal Posts: 2,617	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

10-25-2014, 04:57 PM	#18
TerryH Senior Member Join Date: May 2010 Location: Fountain Valley, Calif. Posts: 937	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.

10-26-2014, 12:57 PM	#22
Juggler Senior Member Join Date: Aug 2010 Location: Phoenix AZ/Bath UK Posts: 481	Re: Flywheel weight?? Thanks Bill and Derek - if I find that article I'll report back Regards Juggs

10-26-2014, 01:58 PM	#24
hardtimes Senior Member Join Date: May 2010 Location: South California Posts: 6,188	Re: Flywheel weight?? Hey TerryNJ, 'free up HP' , is the most succinct and accurate explaination, for what 'lightened wt' flywhl does, IMO. I have never seen any reasonable stmt of how lightening the flywhl ..has negative result (s), other than 'if ain't stock'.

10-26-2014, 03:08 PM	#27
Purdy Swoft Senior Member Join Date: May 2010 Location: Alabama Posts: 8,099	Re: Flywheel weight?? I remember Marco mentioning lugging around corners in high gear with full advance being a bad thing and I agree that it is. Higher gear ratios only make matters worse in such situations. I agree that driving style or skills make all of the difference. I only run 3.78 gears in mine and the lower ratio lessens the risk of lugging. Corner turns can be made in high gear if enough speed is maintained to avoid lugging. I can see no advantage for a heavy flywheel in this day and time. We don't need to creep over sand beds and rutted trails like many had to do in olden times. That said my experience is that a light flywheel will give the most noticable increase in accelleration and driveability next to a higher compression head .