Flywheel balancing

R

roy green coupe

Member
I will be replacing my transmission in the near future and was thinking I would like to have the balance of the flywheel and clutch verified since I don't know their history. I've had balancing done on other engines but usually I brought everything along with the crankshaft. Is there a shop with a means to balance just the flyweel in the east pa. or NJ area ?
 
Yeah Roy, There is! The guy's a NAPA dealer. He uses the name Speed Equipment Corp. He did a few for me. The address is Speed Equipment Corp ' 2535 Street Rd, Bensalem The phone number is 215-638-0300. He has quite a well equiped machine shop. Another Guy who may be able to do it (??) Is Majewsky machine in Trenton, NJ He has the fixture for both Manifolds and heads. He is listed under the vendors at the beginning of the forum.
GTerry
 
So the bigger issue you have is how do you know what the crankshaft is balanced to? Is it possible the crankshaft & flywheel were balanced as an assembly? While this habit has been frowned upon during recent years, it was normal protocol for engine rebuilders several decades ago to do the two as a package.
 
Yeah, Brent You're right about that! That business of balancing the parts all together is a lazy man's way of doing it. Like that's the only engine that part will ever be on, It sounds like a great idea but balancing separately seems better, more reliable. But the 63 Lbs whirling mass is the largest amount of weight of that particular assy and therefore the one most likely to affect the running.

Roy, you might consider taking a few lbs off of it. The engine will rev up faster and there is less weight on the rear bearing (It'll be easier to reinstall ) The plans for taking it down are available here. I lowered mine to about 56 -57 lbs ,
about 10% but it was on the outer dia., where it helps the most. Check your ring gear for wear, it may need replacing.
Terry



BRENT in 10-uh-C said:
So the bigger issue you have is how do you know what the crankshaft is balanced to? Is it possible the crankshaft & flywheel were balanced as an assembly? While this habit has been frowned upon during recent years, it was normal protocol for engine rebuilders several decades ago to do the two as a package.
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Thanks again Terry and Brent for your thoughts, I had thought about that possibility and was thinking if the machinist said it was close I might just leave it alone but if it happened to be out significantly in his opinion then I would have him correct it. This car was redone about 2005 but I don't have much info about what was done. Seems like some things were done well but I have corrected enough things that I have lost confidence in the work that the owner did himself. The engine has definitely been rebuilt and I hope that he didn't do it. I do have some vibration at higher rpms but with stock motor mounts it may just be the nature of the beast. I was wanting to just make sure he didn't just buy an engine and never checked the flywheel before putting it on. That is such a large mass of iron spinning I just thought it might be worth checking. I read so many different opinions about lightening on here that I couldn't tell if I should do that or not. I will study that some more.
 
I've had both lightened and stock. The lightened will give you a bit more quickness for sure. I don't know that it makes it run as smoothly though. I think the balancing is far more important than the weight. JMHO and I'm no expert, just my driving experience.
Dave Mc Arthur
 
I never balanced anything but lawn mower blades and they're pretty elementary. But balancing a spinning mass like a wheel or flywheel is beyond me. I've seen plenty of tires balanced. What baffles the spit out of me is how the machine can not only locate the heavy (or light as the case may be) side, but the amount of imbalance. I worked with some older machinists who had worked at Curtis Wright, Fairfield, during the war, Balancing propellors. They way they did it was to put the prop on a mandrel that fit on two rails and allow it to spin till it's heavy blade was hanging down. It gave you the heavy side, but not the amount. Something like an old bubble balancer. I think this is "Static" balancing, while spinning the part is called "Dynamic" Balancing. The Mod.A does not have to power through mud clogged roads today. Today's A's are not bull dozers or pseudo Farm Tractors. They are more like pampered pets. They really don't need such heavy flywheels. But whatever the weight, they need to be properly balanced.
Terry



roy green coupe said:
Thanks again Terry and Brent for your thoughts, I had thought about that possibility and was thinking if the machinist said it was close I might just leave it alone but if it happened to be out significantly in his opinion then I would have him correct it. This car was redone about 2005 but I don't have much info about what was done. Seems like some things were done well but I have corrected enough things that I have lost confidence in the work that the owner did himself. The engine has definitely been rebuilt and I hope that he didn't do it. I do have some vibration at higher rpms but with stock motor mounts it may just be the nature of the beast. I was wanting to just make sure he didn't just buy an engine and never checked the flywheel before putting it on. That is such a large mass of iron spinning I just thought it might be worth checking. I read so many different opinions about lightening on here that I couldn't tell if I should do that or not. I will study that some more.
Click to expand...
 
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The question for me is how did Ford balance these things at the factory? Did they balance the crankshaft and flywheel as an assembly or separately?
 
They were balanced separately as best I can tell. Some of what I read and what I have been told, but I have not read actual documentation that proves this.

The crank was precision ground. The flywheel located to less then .001" off center line from the mains. This is the first important consideration. Most cranks ground today are not that close, some people consider .002" ok. We have one as far as .008" in our pile of cranks. (we have like 30 engines).
The crank was balanced to 1/4 Oz. Info on the flywheels is no so detailed from what I know. I do know that NOS Ford flywheels from the 40's were not well balanced. By this time Ford would have contracted the work out or not cared so much it seems. This is from someone who had balanced a few NOS flywheels known to be 40's production.

The rods were made to a certain weight at each end +-1 gram. Factory piston/rod assemblies were within 4 grams of each other. The standard today seems to be rods +-5 grams total weight.

For perspective, please do not hold be to exact details, when my brother was researching balancing machines (he has a crank grinder) to figure out what to buy. One of the companies told him that the flywheel for your basic chevy V8 needs to assembled with the same side up. Just the slop in the bolts is enough to introduce 20 lbs of inbalance when running on the car.

So imagine what a 60 lb flywheel can do with an extra .001" off center.

If you want a nice A engine you have to be anal with the balance of the engine. It may be a simple engine, but it is really a precision built simple engine.
 
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