Flywheel balancing question

[Fairmountvewe]

Or spend most of the weekend, 15 grinding discs, one set of heavy leather gauntlets (don't ask.  Its embarrassing), a Canadian Tire 4 1/2 inch grinder (died just before I finished ... RIP) and viola... no more counterweights.  Now to static balance the wheels.  But that is a job for next weekend.

[cgwymp]

+1 XYZer's comment.  I'd also be concerned that the crank mounted counterweights were designed to do only part of the job, and thus the flywheels also having counterweights.  Only a cautious running will tell... 

Good point -- I keep forgetting to assume nothing with these engines. If you were to take the neutral-balance approach, probably best to balance the 'wheels by adding temporary weight until you determine if the crank weights are partial balance or not....

[Fairmountvewe]

Thats the plan.  I want to find a source of stick on weights first.  Hopefully at a price that even a small time farmer like myself can afford   That is this weeks job.

[xyzer]

xyzer, that is completely true when pistons rise and fall together, such as on a parallel twin with a "360" degree crankshaft, such as many motorcycles. In such a case, placing weights on the flywheels and not the crank would be crazy. However, a parallel twin, like the lister, with a 180 degree crankshaft has perfect primary balance (one piston goes up and the other down, perfectly offsetting each other) but adds rocking couple, as the cylinders are side by side. The end result of a 180 degree crankshaft is an engine that has an uneven firing order, something weights cannot compensate for. And, in the case of the Lister Diesels with the cylinders quite far apart, extreme rocking couple. Something best compensated for, by 2 counter-rotating balance shafts.  

That changes things for sure! Is the flywheel weight to smooth the rocking? I would still have to do a careful test run and watch its behavior.

[carlb23]

here is a little over 5.5lbs for 18 dollars on fleabay

http://www.ebay.com/itm/Stick-on-Self-Adhesive-Wheel-Weights-1-4oz-or-25-ounce-360-pieces-/290902716458?pt=Motors_Automotive_Tools&hash=item43bb27302a&vxp=mtr

[Quinnf]

Don't assume that your flywheels will have equal counterweights.  Here's what I did to figure out what the weight was on my flywheels:

I borrowed a friend's lathe and turned a top-hat shaped insert out of alulminum to fit the bore of the flywheel and balanced it on a sharpened tip of a 5/16" drill rod spot welded to a piece of steel which I held in a vise.



Set a bullseye-type bubble level in the center of the insert once the flywheel was placed on it, and added weight to the rim opposite the cast-in counterweight until the bubble centered on the insert.  Then weighed the weights which were either 35 ozs. 48 ozs, depending on which flywheel you weighed. 



Once you've determined the weight of the cast-in counterweight you can add a like amount of weight opposite it to neutralize its effect. 

[Fairmountvewe]

How did you get the flywheel insert to balance on the 5/16 drill rod?  Did you bore a matching conical recess into the base of the "top hat" or does the drill rod fit quite deeply into the insert?  It seems to me that if the flywheel was out of balance by almost any amount at all, it would slip off that pointed drill rod.  Or am I missing something here?

[Quinnf]

Yes, here's the way it's made:

[BruceM]

Someone here made a flywheel balancer by using 2" OD, 1" id bearing to bush the hub of the flywheels, and then 1" steel shaft, supported at both ends.  I thought that was ingenious and would work well for someone without a lathe. 

[cujet]

xyzer, that is completely true when pistons rise and fall together, such as on a parallel twin with a "360" degree crankshaft, such as many motorcycles. In such a case, placing weights on the flywheels and not the crank would be crazy. However, a parallel twin, like the lister, with a 180 degree crankshaft has perfect primary balance (one piston goes up and the other down, perfectly offsetting each other) but adds rocking couple, as the cylinders are side by side. The end result of a 180 degree crankshaft is an engine that has an uneven firing order, something weights cannot compensate for. And, in the case of the Lister Diesels with the cylinders quite far apart, extreme rocking couple. Something best compensated for, by 2 counter-rotating balance shafts. 

That changes things for sure! Is the flywheel weight to smooth the rocking? I would still have to do a careful test run and watch its behavior.

On a 180 degree crankshaf lister twin, flywheel weights won't do much to cure rocking couple. The best we can hope for is a small improvement of the vibration node in one axis.

However, you are the perfect guy to machine up a set of "counter rotating" balance shafts for various lister twins!!! Could bolt them right on the crankcase door and drive them with a toothed belt, like a camshaft.

[Fairmountvewe]

Pictures  
starting the process

one down, one to go

counterweights

[Fairmountvewe]

So the next thing is to balance them.  I am certainly not any kind of machinist (I am trying to learn, but man that is a long row to hoe!), so coming up with an intricate (for me) design like Quinnf's isn't in the cards.  I think I will make a 2" plug for the bore, drill and tap for a 1/2" eyebolt, and suspend it horizontally from the tractor loader.  Then it should be stick-on weight, stick-on weight, stick-on weight and voila....Listeroid nirvana.  No?

[cujet]

I balanced "Horsepoor's" 6/1 last night, using an ACES 20-20 helicopter and propeller balancing kit. His Lister is a standard configuration, with counterweighted flywheels. And he runs it at 650 or 800 RPM depending on power needs.

At 650 RPM, I read nearly 3 IPS vertical and about 0.25 IPS horizontal. Meaning, the engine was significantly underbalanced. We first tried 2 strips of 3 OZ wheel weights, to augment the cast in flywheel weights. That made a small improvement.

So, noting the minor improvement, I chose to install 4ea. strips of 3 OZ wheel weights on each flywheel. In other words, a total of 24 OZ. The balance came out just slightly underbalanced. With about 1 IPS vertical and 0.8 horizontal.

Increasing the RPM to 800 resulted in slight overbalance, with IPS readings of 1 IPS vertical and 1.2 horizontal.

That's probably as good as a lister single can get.

[BruceM]

Nice work, Cujet!
Tell us more about this ACES 20-20 unit.  Does it have an accelerometer sensor that you secure to the engine?

[tank9008]

Hi all.  I have a question, but first a little background.  A bunch of years ago, thanks in no small part to Rocketboy F1's excellent website, and a loving and understanding wife, I found myself in possession of a 12/2 engine.  Now here is where the fun starts.  The engine is internally counterbalanced.  The flywheels are the 6/1 counterbalanced type.  It seems to me that I need to "un" counterbalance my flywheels.  I have toyed with the idea of buying new ones, but a big part of me wants to solve this problem.  I have debated using an angle grinder to grind out the weight, but from all that I have been able to gather that is a messy, time consuming, fraught with potential failure kind of idea.  My son (a MatTech in the CF) gave me an idea. What would stop me from putting a bunch of lead opposite the counterbalance and effectively oppose the generated forces?  I really don't know.  What say ye?

which brand u hve Lister 12/2 engine snd me snd me engine no , plz reply me by mail

     mtank9008@yahoo.com

     tank9008@co.in

i can sole ur problem

............................ M.V.Tank