Counterweighted Crank

[DD931]

OK, I know I'm probably pouring gasoline on a fire, but I'm interested in your collective thoughts. I'm planning to take my engine to Schwalm's for a rebuild later this year. Should I do a counterweighted crank? What are the pro's and con's? Experiences?

[Dave in MN]

I suggest a counterweighted.
Pro: Properly installed and balanced counterweights take some load off the main journals.
Con: The rear main cap/bearing is difficult to remove/service with counterweights installed.

I have counterweights installed on my touring engines and am very satisfied with the service they have delivered. One of my insert bearing counterweighted engines with an almost stock oiling system has over 95,000 miles on it. I do use an oil filter and have piped oil to the center main. I have not even had the pan off this engine. It is just like the Energizer Bunny....Keeps going and going...
Good Day!

[redmodelt]

If you install one, make sure everything is balanced from the pulley in front to the clutch pressure plate.

[Railcarmover]

Alot depends on what else you are planning to do to the engine..and how well you maintain the engine.Properly maintained, a dynamic balanced crankshaft on grade 2 babbit will give thousands of miles of service.

[wensum]

My understanding is that if you install a counterweighted crankshaft, then it is desirable to lighten the flywheel by at least the amount of weight the counterweights add to the original shaft weight, if not more?

[jhowes]

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What is a "grade 2 babbitt"? Are all weights welded on or are some still bolted on? What are the pro's and con's of doing it either way? Jack

[nick c]

I think Dave may have ran a steel line from oil galley to the center main and added an oil filter.

I've seen pics of weights on crank, they use 1 bolt at 12 oclock then weld 1 inch one both sides at the ends, this is how I plan on doing mine.

carry on

[Joe K]

Grade 2 Babbitt is one of the ASME formulations for babbitt shown at http://www.neymetals.com/product/babbitt-metals/

IIRC, Ford did not have the advantage of ASME standards at the time of the Model A but instead had his own formulation - which is "close" to Grade 2.

A possibly closer formulated babbitt is shown on the same page further down as NEY Product Code 787NFMT. "Model T" babbitt.

Steve Ross did assays of babbitt trying to get closer to what Ford did - these studies were originally posted on the 'net, but have since been removed. My last communication with Steve provided a PDF of the removed web-page - which I now can't find.

Edit: I found a Steve Ross babbitting article online minus pix. He comments some on babbitt techniques/requirements in the article. http://www.antiqueautoranch.com/montana500/adrian/babbitt.html
I have checked the source code and am not finding his babbitt study here or elsewhere online.

The weights are not usually bolted but are typically "pressed" on and fully encircle the round "throws" of the crank-shaft. Many additionally weld the weights in place.

The comments about reducing the flywheel weight are apt as the Model A even in stock version suffers a bit with "spin down before shift" because of an over-heavy flywheel. A counter weighted crank only adds to the defect. Many lighten the flywheel to make the car an easier shift.

Joe K

[Dave in MN]

Originally Posted by nick c

I think Dave may have ran a steel line from oil galley to the center main and added an oil filter.

I've seen pics of weights on crank, they use 1 bolt at 12 oclock then weld 1 inch one both sides at the ends, this is how I plan on doing mine.

carry on

Yes to both modifications. I have been using the A-Ford-Able filter that is incorporated onto the valve chamber cover.
Good Day!

[Jim Brierley]

Have counterweights put on! why does anybody doubt this, All new cars have them and would save money by not using them if not important. Schwalm's does nice work. Different babbitt alloys were used on different applications. Ford's didn't put much of a load on the bearings, but ran no filter so the brgs were subject to dirt and debris getting in the oil. Ford babbitt had more "imbedability" than harder babbitt like Diesel Babbitt. Also use modern oils, and NOT old junk without additives.

[Purdy Swoft]

As Joe K says , a lightened flywheel does make a noticeable difference in gear shifts . A lightened flywheel allows the engine to accelerate quicker . Horsepower is made at higher R.P.M . While a lighter flywheel may not actually add any horsepower , it gets the engine to the point where horsepower is produced quicker for faster acceleration . Removing weight from the flywheel takes weight off the main bearings .


Ford added counter weights to the BB truck crankshafts later in 1932 . People were hauling heavy loads and running the trucks at wide open throttle . The added weight was suppose to smooth out the effects of an unbalanced crankshafts and help the model B engines to last longer . In over fifty years , I haven't had any problems with my model A crankshafts . Many people that have added weights to the model A cranksghafts say that they notice no improvement in smoothness .

[DD931]

Well, thanks all!!! Nobody has said it isn't worth the bother/expense. The argument that it reduces the load on the mains is convincing. Looks like I'll be having the crank counterweighted and the flywheel lightened. Schwalm's offers all this. I'm planning to use them because 1) their reputation is bulletproof, 2) I live about two hours away and 3) I've visited their booth at Hershey several times and love their stuff!! By the way, my brother says that with his car there is a noticeable power increase with the 5.5/1 police head, so I'll be doing that too.

[Railcarmover]

Once again,need to know what you are doing to the engine,and who's crankshaft you are using.Some crankshafts are north of 1000 bucks,might not be worth the expense if youre building a stock engine with a 5.5 head..that money may be better spent elsewhere,like a good down payment on an overdrive or radial tires.A counterbalanced crank is an improvement over a dynamically balanced one,but does the improvement pencil out when the money might be better spent elsewhere?

[Joe K]

A counterbalanced crank is an improvement over a dynamically balanced one,but does the improvement pencil out when the money might be better spent elsewhere?

Careful here. Counterbalanced cranks are intrinsically static balanced. NO crankshafts are completely dynamically balanced. Even a counterbalance crank can be "optimized" in its dynamic balance by having it done.

As others have said, do the front pulley, crank, flywheel and pressure plate together.

And don't mix up relative orientation of the parts!

Joe K

[Gene F]

Schwalms counterweighted my crankshaft, balanced it, then added the flywheel and balanced, then the pressure plate and balanced the entire assembly again, then matchmarked everything and sent it back to me. My engine builder is an old finikey guy, and when I went to pick it up he asked, who did the work. I told him and asked why. He said they plainly knew what they were doing because they did a real nice job. Tall praise from him, trust me! Brumfield head, 30 lbs off the flywheel (my last engine was 20, and I was not satisfied), the big stainless valves, a bigger throat intake and B carb, plus a 3/4 (five-journal) grind on my cam from Bill Stipe.
I am happy that I have a counterweighted and properly balanced system. I have fillings in my teeth, and the vibrations in the rear view mirror of a non-counterweighted engine tell the story. FYI: B/W O/D. I added a super heavy duty radiator from Snyders, and cast iron drums. Now I have a terriffic car to drive. It still looks and acts like an A too. What a joy to drive!

[Railcarmover]

Originally Posted by Joe K

Careful here. Counterbalanced cranks are intrinsically static balanced. NO crankshafts are completely dynamically balanced. Even a counterbalance crank can be "optimized" in its dynamic balance by having it done.

As others have said, do the front pulley, crank, flywheel and pressure plate together.

And don't mix up relative orientation of the parts!

Joe K

Uhh.be careful of what? All crankshafts are dynamically (spin) balanced.By virtue of dynamic balancing static balancing occurs. Ford believed that dynamic balancing the model a crankshaft was sufficient.Ford counterbalanced the 4 cylinder crankshaft in late '32,to offset the power stroke impulse on the main bearings.And that is all counterbalancing does,offset the power stroke impulse.your engine does not run smoother.

If you use a mechanical advance distributor you eliminate the chance of the harmful effect of detonation on the main bearings.Proper engine timing with proper bearing maintenance a model a dynamically balanced crankshaft beared by US grade 2 babbit will have a long life cycle making the decision to use a counterbalanced crankshaft not the slam dunk some folks think it is.

[Joe K]

Originally Posted by Railcarmover

Uhh.be careful of what? All crankshafts are dynamically (spin) balanced.By virtue of dynamic balancing static balancing occurs. Ford believed that dynamic balancing the model a crankshaft was sufficient.Ford counterbalanced the 4 cylinder crankshaft in late '32,to offset the power stroke impulse on the main bearings.And that is all counterbalancing does,offset the power stroke impulse.your engine does not run smoother.

If you use a mechanical advance distributor you eliminate the chance of the harmful effect of detonation on the main bearings.Proper engine timing with proper bearing maintenance a model a dynamically balanced crankshaft beared by US grade 2 babbit will have a long life cycle making the decision to use a counterbalanced crankshaft not the slam dunk some folks think it is.

Not to send you off in a huff. Examine https://www.slideshare.net/Atishkuma...tion1-37248978. Particularly note slide 9 below.





The part in red of the first paragraph was all I was getting at.

In truth I think we're saying the same thing and agree on the same thought. And yes, smooth motors are happy motors. The drivers even more so.

Joe K

[Kohnke Rebabbitting]

The Babbitt article, has many misconceptions, and downright mistakes! Any one using it for step by step babbitt instruction, will be disappointed with there results.

Herm.

[johnneilson]

I am sure that Herm is correct on the Babbitt details.
There is another problem with the article, the dynamic balance of a 4 cyl inline motor can never be achieved due to the differences in acceleration of the pistons.
You can get close and at low speeds it will be perceived as so, but still not correct.


John

[Pete]

I am wondering if any of you that are giving balancing advice have actually run a balancer?