I'm having a hard time trying to decide between using a counterbalanced or stock crankshaft. I like the low end torque of the stock crankshaft and stock flywheel but not the vibration that comes with it. I am impressed with the smoothness of a counterbalanced crank and lightened flywheel with a v8 pressure plate. I realize there is a huge difference in cost. What are the implications of using a stock flywheel and a counterbalanced crankshaft??
Balanced Crankshaft vs Stock
- Thread starter goodcar
- Start date
P.S.
Well-known member
My experience is just opposite. My counterbalanced Model A motor with Snyder 5.5 bead is not as smooth as my stock motor with stock head.
Both motors rebuilt by same shop. Both have new pistons, rods, valves, etc.
I also notice a difference in performance. The balanced motor has a pretty linear torque curve, but falls off pretty rapidly. The stock motor is in the heavier car (29 Fordor), but seems to pull better in some instances. For example, when transitioning from flat ground to a steep-ish hill, the balanced motor just slowly loses speed until I have to eventually downshift and crawl to the top. On the same hill- The stock motor loses speed until it drops to around 40 MPH, then it just digs in and pulls. I prefer the stock setup. Henry Ford knew what he was doing!
The balanced motor is way quicker off the line, and pulls really hard on flat ground. However, the stock motor is just more fun to drive. Not as fast off the line, but you spend more time in 3rd and less time downshifting to keep the motor happy.
Future plan is to pull the Snyder head off the balanced motor and go back to the stock head and see if that helps it be more like the stock motor.
Both motors rebuilt by same shop. Both have new pistons, rods, valves, etc.
I also notice a difference in performance. The balanced motor has a pretty linear torque curve, but falls off pretty rapidly. The stock motor is in the heavier car (29 Fordor), but seems to pull better in some instances. For example, when transitioning from flat ground to a steep-ish hill, the balanced motor just slowly loses speed until I have to eventually downshift and crawl to the top. On the same hill- The stock motor loses speed until it drops to around 40 MPH, then it just digs in and pulls. I prefer the stock setup. Henry Ford knew what he was doing!
The balanced motor is way quicker off the line, and pulls really hard on flat ground. However, the stock motor is just more fun to drive. Not as fast off the line, but you spend more time in 3rd and less time downshifting to keep the motor happy.
Future plan is to pull the Snyder head off the balanced motor and go back to the stock head and see if that helps it be more like the stock motor.
Kohnke Rebabbitting
Well-known member
Mr. P.C., there can be many things that can cause that besides a balanced crank, and probably is.
Herm.
Herm.
TerryH
Well-known member
Well, I have the Snyder 5.5 head, lightened flywheel, and v-8 clutch and pressure plate. Before I had it done, someone told me not to....it will ruin the car, and never drive the same. I've had this 10 years now, and absolutely no regrets. My engine runs very smoothly, with little to no vibration. If there is some effect to very low speed pulling, it is minimal, and my car still pulls very well. There is significantly less effort to depress the clutch, which I happen to like.
tbirdtbird
BANNED
,,,
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Patrick L.
Well-known member
I think I would prefer a counter-weighted crank and it is my understanding that a minimum of 12 lbs needs to be removed from the wheel for that.
I happen to like that heavy wheel, I'm in no hurry and the older I get the more shiftless I become.
I happen to like that heavy wheel, I'm in no hurry and the older I get the more shiftless I become.
H. L. Chauvin
Well-known member
Hi Mr. goodcar,
FWIW: All above replies are most sincere and extremely helpful in trying to address your question(s).
1. To add just a very little, just ask yourself .......... What Model A engine results are you trying to achieve?
2. Maybe secondly, ask yourself, ..... How many modern cars are on the road today with much lighter flywheels than that of Model A flywheels ....... and how many modern cars are on the road today with very properly balanced matching cranks and running gear?
3. Then ..... Who has the proper tools, equipment, and "knowledgeable & experienced" mechanics to take a "well used" ....... 80+ year old ...... worn out Model A engine ......... and provide a properly balanced, aligned, & almost perfect Model A engine?
4. By now, (especially after thoroughly investigating various shops concerning the very most important ingredients in #3. above), ..... the answer my friend, is written in the wind ...... just open your wallet and grab for it.
Sincerely hope this helps ..... & if not please let us know.
FWIW: All above replies are most sincere and extremely helpful in trying to address your question(s).
1. To add just a very little, just ask yourself .......... What Model A engine results are you trying to achieve?
2. Maybe secondly, ask yourself, ..... How many modern cars are on the road today with much lighter flywheels than that of Model A flywheels ....... and how many modern cars are on the road today with very properly balanced matching cranks and running gear?
3. Then ..... Who has the proper tools, equipment, and "knowledgeable & experienced" mechanics to take a "well used" ....... 80+ year old ...... worn out Model A engine ......... and provide a properly balanced, aligned, & almost perfect Model A engine?
4. By now, (especially after thoroughly investigating various shops concerning the very most important ingredients in #3. above), ..... the answer my friend, is written in the wind ...... just open your wallet and grab for it.
Sincerely hope this helps ..... & if not please let us know.
forever4
BANNED
There have been a variety of Ford crankshaft and flywheel and clutch combinations, and resulting rotating masses.
See the link for a discussion on this.
http://www.fordgarage.com/pages/rotatingmass.htm
See the link for a discussion on this.
http://www.fordgarage.com/pages/rotatingmass.htm
VFRhugh
Senior Member
Don't know if my experience is typical but the difference between stock and modified engines is dramatic. My stock engine is smooth up to 30mph then the vibration increases proportionally to 45 mph where it's scary to go any faster. I installed a Mitchell 1.26% overdrive so i could live with the limitations of this particular engine.
The odometer rolled over 500 miles today on my counterbalanced engine. Where the old engine was getting worse the CB gets smoother. I won't rev it past 2200 rpm but it could easily. I'm running a 6:1 HC head, IB330 cam, 43# flywheel, A pressure plate, stock dizzy, &. Marvel Schebler carb. I didn't weigh the CB crank when it was out of the block but wish I had. It has shrink-on weights and looks to be old.
I can still putt around the neighborhood and accelerate quick enough to not hold up traffic on the main roads. First to second shift is a big improvement with this setup.
Although not related to this thread, I see a lot of head gasket/water leak threads lately. During the rebuild I had my machine shop surface the block and the new 6:1 head. I used a copper "B" gasket with spray on copper coat sealant. It took three heat cycles to hold 55# torque. So far no water leaks.
Also as Herm says there are a lot of things that need to be correct to have a perfect engine. Mine is a collection of old and new parts assembled in my garage with advice from a couple of knowledgeable Barners. I feel fortunate it turned out good for me.
Hugh
The odometer rolled over 500 miles today on my counterbalanced engine. Where the old engine was getting worse the CB gets smoother. I won't rev it past 2200 rpm but it could easily. I'm running a 6:1 HC head, IB330 cam, 43# flywheel, A pressure plate, stock dizzy, &. Marvel Schebler carb. I didn't weigh the CB crank when it was out of the block but wish I had. It has shrink-on weights and looks to be old.
I can still putt around the neighborhood and accelerate quick enough to not hold up traffic on the main roads. First to second shift is a big improvement with this setup.
Although not related to this thread, I see a lot of head gasket/water leak threads lately. During the rebuild I had my machine shop surface the block and the new 6:1 head. I used a copper "B" gasket with spray on copper coat sealant. It took three heat cycles to hold 55# torque. So far no water leaks.
Also as Herm says there are a lot of things that need to be correct to have a perfect engine. Mine is a collection of old and new parts assembled in my garage with advice from a couple of knowledgeable Barners. I feel fortunate it turned out good for me.
Hugh
Attachments
Quigley1930
Senior Member
Balanced crank and stock head makes me a happy camper
Sewall
Sewall
Tom Wesenberg
Well-known member
The weight of the flywheel is no magic number. You don't have to remove weight when you add counterweights. It's just that most people feel they have to remove the same weight off the flywheel that the weights have added to the crankshaft. I'll be adding the heavy weights that Hugh shows, but haven't decided yet if I will remove any weight from the flywheel.
Adding counterweights is what I consider the best thing to do to the engine, followed by a higher compression head. There's a good reason all engines today have counterweighted crankshafts, and I'm surprised Henry didn't do it for the Model A.
Adding counterweights is what I consider the best thing to do to the engine, followed by a higher compression head. There's a good reason all engines today have counterweighted crankshafts, and I'm surprised Henry didn't do it for the Model A.
H. L. Chauvin
Well-known member
Hi Mr. Goodcar,
For over 20 years I have been reading Model A Forum comments from Model A owners who for the past 20 years have been reporting results performance from sticking their wet fingers out of their Model A windows while driving with counterweights and lightened flywheels to determine Model A engine performance, torque, etc.
Please call Mr. Ron Kelley who advertises in "The Restorer".
As a former Texas Instrument Technician, he has "calibrated" dynamometers to evaluate performance engines with lightened flywheels and weighted cranks.
I am please what he did with my flywheel and crankshaft ..... at 55 mph ..... my Model A engine is as smooth as a Mercedes.
Others like him I feel may be as good, just never tried and experienced their work.
Your wallet .... your money .... you asked .... just best advice I can give.
For over 20 years I have been reading Model A Forum comments from Model A owners who for the past 20 years have been reporting results performance from sticking their wet fingers out of their Model A windows while driving with counterweights and lightened flywheels to determine Model A engine performance, torque, etc.
Please call Mr. Ron Kelley who advertises in "The Restorer".
As a former Texas Instrument Technician, he has "calibrated" dynamometers to evaluate performance engines with lightened flywheels and weighted cranks.
I am please what he did with my flywheel and crankshaft ..... at 55 mph ..... my Model A engine is as smooth as a Mercedes.
Others like him I feel may be as good, just never tried and experienced their work.
Your wallet .... your money .... you asked .... just best advice I can give.
CarlG
Well-known member
I can only echo these comments. My "Ron Kelley Engine" is better than I could ever have dreamed.
Chuck Sea/Tac
Well-known member
As you probably know , in early spring of 32 , ford four cylinders were factory counterweights. And all B block factory rebuilds after, were as well. must of been a reason. ( tongue in cheek)
updraught
Well-known member
A heavy flywheel is excellent for off road. Set the hand throttle at just off idle and let it go.
http://www.rubicon-trail.com/prep-CD/Rubicon/img/studebaker-sluice.jpg
http://www.rubicon-trail.com/prep-CD/Rubicon/img/studebaker-sluice.jpg
Kevin in NJ
Well-known member
Really the discussion is going the wrong way.
You need to first understand why you get vibration and then think about how you will be using the car.
The A engine was super well machined and balanced off the factory floor. I am talking what we consider race car engine type balancing and control. The crank was machined to tight tolerances and then balanced with the flywheel hung less then .001" off center. Then the rods were build +-1gram at each end with the piston rod set all being within 4 grams of each other. You also have to consider the new cam along with the correct lifters and valves that are not beat down in the block.
So when you build an engine today you need to return it to the factory specs for a reliable (50,000 to 80,000 miles) engine that will be happy to run the car at 60 MPH.
Now if you are a just a local driver with an occasional long trip then everything sort of stock will work fine and last a long time.
If you are going to do 10k a year then extra money on a balanced crank and such would be a wise investment.
The real key is having an engine builder that has OCD and knows the factory specs and how to adapt what he is doing to the engine. By adapt as in you put modern valves in and he knows what works gap wise for the expansion rate of the valve metal for example.
Today engines are frequently thrown together with the flywheel flange off center, throws not ground on the right centerlines, rods 5 gram total weight, pistons 20 gram different and so on. Of course each engine is going to have its own vibration and set of odd problems. What can you expect.
Clearly, if you start playing with cams and carbs you may give up something to get something else. You need to always keep in mind a properly rebuilt to factory car runs 60 MPH no problem and is reliable and can be beat to death every day and you keep on driving it. That is how the cars were run on the crappy roads of the day everyday back in the day.
You need to first understand why you get vibration and then think about how you will be using the car.
The A engine was super well machined and balanced off the factory floor. I am talking what we consider race car engine type balancing and control. The crank was machined to tight tolerances and then balanced with the flywheel hung less then .001" off center. Then the rods were build +-1gram at each end with the piston rod set all being within 4 grams of each other. You also have to consider the new cam along with the correct lifters and valves that are not beat down in the block.
So when you build an engine today you need to return it to the factory specs for a reliable (50,000 to 80,000 miles) engine that will be happy to run the car at 60 MPH.
Now if you are a just a local driver with an occasional long trip then everything sort of stock will work fine and last a long time.
If you are going to do 10k a year then extra money on a balanced crank and such would be a wise investment.
The real key is having an engine builder that has OCD and knows the factory specs and how to adapt what he is doing to the engine. By adapt as in you put modern valves in and he knows what works gap wise for the expansion rate of the valve metal for example.
Today engines are frequently thrown together with the flywheel flange off center, throws not ground on the right centerlines, rods 5 gram total weight, pistons 20 gram different and so on. Of course each engine is going to have its own vibration and set of odd problems. What can you expect.
Clearly, if you start playing with cams and carbs you may give up something to get something else. You need to always keep in mind a properly rebuilt to factory car runs 60 MPH no problem and is reliable and can be beat to death every day and you keep on driving it. That is how the cars were run on the crappy roads of the day everyday back in the day.
clo2jim
Senior Member
This past summer, my engine builder (we travel together with 4-5 Model's A on car tours and to car shows) decided it was about time, we adjusted the shims for the babbit bearings on our 1930 Roadster - he said should be done after 1,500/2,000 miles. I said BTW, there is 6,000 miles on the engine since we overhauled it.
Anyway, the engine was running fairly well, but did have a noticeable vibration above 40 MPH. Anyway we went through adjusted all the connecting rods shims ( shims thickness removed ranged from 4-thou / 4-thou (total 8) for one connecting rod (#2, I think) to no shims removed for #4 connecting rod) I was the guy on the crank running the motor over after each adjustment. Remove only one shim at a time (2-thou) - turn the motor over until it would not turn over by the crank and then put one (2-thou) shim back in.
Once we completed the connecting rods shims we went on to the main bearings. We removed shims on all three main bearings. In the end we had a very tight motor than I could turn over with the crank but it was tough. We went from a engine that would turn over with essentially any small resistance (spark plugs out) to a motor that was tight.
The motor was started after using the starter and started with no problems. One of the best things I noticed right away was now smooth the motor was. There was a few times that I discovered that I was traveling at 50-55 mph and not realising it since the motor was running so smooth
So one thing to look at if your motor has vibrations and has babbit bearings is to check your bearing clearances and make adjustments in the shims.
So this winter, one of my projects, is to check the bearing clearances on our Town Sedan and make adjustments to the to the shims to tighten thing up. Now, when I have the spark plugs out, I can turn the motor over easily with the crank using one fingers. The engine is running great on this car at this time.
Anyway, the engine was running fairly well, but did have a noticeable vibration above 40 MPH. Anyway we went through adjusted all the connecting rods shims ( shims thickness removed ranged from 4-thou / 4-thou (total 8) for one connecting rod (#2, I think) to no shims removed for #4 connecting rod) I was the guy on the crank running the motor over after each adjustment. Remove only one shim at a time (2-thou) - turn the motor over until it would not turn over by the crank and then put one (2-thou) shim back in.
Once we completed the connecting rods shims we went on to the main bearings. We removed shims on all three main bearings. In the end we had a very tight motor than I could turn over with the crank but it was tough. We went from a engine that would turn over with essentially any small resistance (spark plugs out) to a motor that was tight.
The motor was started after using the starter and started with no problems. One of the best things I noticed right away was now smooth the motor was. There was a few times that I discovered that I was traveling at 50-55 mph and not realising it since the motor was running so smooth
So one thing to look at if your motor has vibrations and has babbit bearings is to check your bearing clearances and make adjustments in the shims.
So this winter, one of my projects, is to check the bearing clearances on our Town Sedan and make adjustments to the to the shims to tighten thing up. Now, when I have the spark plugs out, I can turn the motor over easily with the crank using one fingers. The engine is running great on this car at this time.