Does flywheel need to be balanced

[Terry Burtz, Calif]

Originally Posted by Seth Swoboda

As I said, balance the entire rotating assembly. You don't need to be a genius to figure this out. Any competent automotive machine shop will do this without question.

Competent builders and machine shops are hard to find. Everything needs to be balanced separately. We have builders of the new engine that don't understand this and have the flywheel and pressure plate balanced together by only removing weight from the flywheel.

Ford engineering in the 1920's was behind the competition. In 1914, the Dodge Brothers left Ford and started making their own automobiles. By 1927, their 40 HP Fast 4 engine used inserts on the 5 main bearings and 4 connecting rods.

[old31]

I am going to make a wild guess that Ford's engineers knew a 5 main was the way to go. But Henry, being Henry, knew that a 3 main was cheaper and that is what he did.

[old ugly]

i think in the late 1920s selling an affordable car that Ford could mass produce cheaply was more important than having a bit of vibration.
the first Model A was completely solid mounted engine and tranny (which mine is). so without isolating the engine and trans assemblies there is bound to be vibration.

Competition and consumer knowledge is what made cars nicer all around. If it wasn't Ford would still be building and selling Model Ts

I kinda like driving old sh&# the way it was made 98 years ago.

Embrace the vibes.

[ursus]

Originally Posted by Terry Burtz, Calif

Competent builders and machine shops are hard to find. Everything needs to be balanced separately. We have builders of the new engine that don't understand this and have the flywheel and pressure plate balanced together by only removing weight from the flywheel.

Ford engineering in the 1920's was behind the competition. In 1914, the Dodge Brothers left Ford and started making their own automobiles. By 1927, their 40 HP Fast 4 engine used inserts on the 5 main bearings and 4 connecting rods.

Chevrolet introduced its 6-cylinder engine in 1929 and, until the mid-30's, it ran only three main bearings of cast babbitt construction. My Dad's 1929 Chev could reach 70 MPH (on a good day) but there were some nervous vibrations along the way.

[Flathead]

Originally Posted by Terry Burtz, Calif

Competent builders and machine shops are hard to find. Everything needs to be balanced separately. We have builders of the new engine that don't understand this and have the flywheel and pressure plate balanced together by only removing weight from the flywheel.

Ford engineering in the 1920's was behind the competition. In 1914, the Dodge Brothers left Ford and started making their own automobiles. By 1927, their 40 HP Fast 4 engine used inserts on the 5 main bearings and 4 connecting rods.

Absolutely. When you balance flywheel and pressure plate together you have really not balanced anything, if the pressure plate ever needs replacing you must start over to maintain balance.

[nkaminar]

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When in 1969 I worked for a company that produced gas turbine engines, the components were all balanced individually and then assembled with no further balancing. The components were the compressor and exhaust disks with the blades attached. I cannot remember if there was a separate shaft, but it there was that was balanced separately.

[40 Deluxe]

Originally Posted by Joe K

I agree with Brent too.

Be careful the balancer/machinist doesn't "squeeze" too hard between centers and permanently deform the crank.

Joe K

This is new to me. How does a balancer "squeeze" and deform a crankshaft?

[nkaminar]

If the balancer is using centers at the ends of the crankshaft. The crankshaft has conical holes drilled in each end that was used to grind the bearings and is used to balance the crank. If the balancer presses in too hard on the ends it could possibly deform the crank at the flanges for the rod journals. The force is off center at those flanges.

Beware that sometimes the centers, the conical holes, are not on center and the journals at the ends should be used.

[Fullraceflathead]

When he says the word balancer he's referring to the machinist or machine operator of the balancing machine.

[Dan McEachern]

Not an expert, but most balancing machines support the part on the journal or shaft surface- not between centers.

[nkaminar]

That would be the best method. There is no guarantee that the centers are true.

[Kurt in NJ]

I have been working on alignment of the headstock and tailstock on my crankshaft grinder and with a skinny model T crankshaft and wondering what distortion is induced by varying the pressure on the centers and saw no changes with different pressures on the centers from the tension spring on the runout of the center main