60 mile per hour all day long?perhaps..

[Railcarmover]

Got an engine from a friend for doing a coupla hours of welding on his '58 Apache 3100 dumping pickup (original aftermarket dual cylinder hoist and pto drive,its very cool).it looked like it had been built not that long ago and he said he pulled it from a car for another guy...said it blew a head gasket..I figured i couldnt go wrong,Id have done the welding for free.Tore it down tonight,was stoked to see the fresh valves


and gleefully pulled the pan...first thing I saw was the glyptal I was downright joyful



Then I noticed the center main had a cauliflower ear of babbit,and knew it was all too good to be true..



I wonder if this engine did a 60 mph all day....oh well I want to run inserts and a counterbalanced crank anyway.I wonder what can be saved,I was thinking the valve job could be lapped back in..or should I just start fresh?

[Tom Wesenberg]

Now is the time to check everything, but the valves look like new, and I wouldn't grind them unless something is wrong with them. Just turn the cam gear around and check the seating area of each valve when it's open.

[Railcarmover]

I agree,the next move is to completely disassemble,measure and magnaflux..If it checks out I'll get started building a touring engine.There's a gentleman in Turlock who has a good reputation for machine work,Ill employ his services if available.I like doing my own assembly work,no one spends the time lapping polishing and 'blueprinting' like an owner can,the labor is free..Got a nice 1/10th gram scale too so I can static balance a bit too.One question I do have is about counterbalanced crankshafts,everyone seems to recommend lightening the flywheel at the same time...not so sure I want to do that,seems to me the heavier flywheel would work in combination with the counterbalance crank and allow a smoother running engine.Sacrifice a little 'spool' up speed for more dampening?

[H. L. Chauvin]

Always an unending conversation about lightened flywheels; however, Ford lightened the B flywheel a bit when he installed the counterbalanced B crank; and many old vintage machinists in our rural area told me in the early 1940's that they were often asked to lighten Model A flywheels for customers.

Engine re-builder Mr. Ron Kelley always recommends lighter Model A flywheels when used with his counterbalanced crank ..... he did mine as such .... no complaints even in hill country.

Seems evaluating different, varying choices of others is done every day with all things ..... I got used to it years ago. LOL

[Kevin in NJ]

No, Babbitt does not just fail from running 60 MPH all day long.

Babbitt fails because it was not done right.

Babbitt seems simple, just pour it and bore it. No, there are many rules you must follow or it will come apart. That Babbitt was not bonded to the cap. Looks like it was tinned, but the babbitt did not get well adhered to the tinning.

Contrary to many peoples opinions. A well balanced system and proper babbitt take a beating and keep on running. It has been our experience that babbitt is just not done right more often then not. With exception to a few shops that know the science of pouring babbitt we have found many guys are just clueless on how to pour babbitt in such a way as to not introduce fail points.

By experimentation we found many ways to screw up babbitt. In talking to various guys doing babbitt we found they were doing things that would lead to babbitt failures like what you see in the above picture.

In the end, if babbitt fails it is because it was done wrong in the first place. I guess I have to add in, you can make it worse by improper balance or running in such a way to cause pre-detonation.

[Kevin in NJ]

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Originally Posted by H. L. Chauvin

Always an unending conversation about lightened flywheels; however, Ford lightened the B flywheel a bit when he installed the counterbalanced B crank; and many old vintage machinists in our rural area told me in the early 1940's that they were often asked to lighten Model A flywheels for customers.

Engine re-builder Mr. Ron Kelley always recommends lighter Model A flywheels when used with his counterbalanced crank ..... he did mine as such .... no complaints even in hill country.

Seems evaluating different, varying choices of others is done every day with all things ..... I got used to it years ago. LOL

Keep in mind, it does not matter how light the flywheel is as if it is well balanced and running on the center line it will not cause bearing issues. The weight of the flywheel only affects the momentum, how fast the engine revs up or spins down.

Bearings only care about oil and forces. Counter balancing is not the critical issue with the A crank (do not get me wrong it can improve it). The critical issue is being anal about machining and balance.

[Railcarmover]

If the flywheel stores energy and dampens pulse..wouldn't the dampening effect of counterbalancing be aided by more flywheel mass then less?

The tinning on the bearing cap is good,it appears the babbit itself failed. Im not trained in poured babbit bearing failure analysis. Usually when an insert bearing fails structurally like this there are telltale heat indications..on this one,the crankshaft looks perfect,however.there is glazing and evidence of light vertical scoring of the cylinder walls from piston heat distortion,that's where Im jokingly naming the thread..from my view,the engine was run hard and fast.Hard enough to create heat,fast enough,long enough to pound out the center bearing..Or Kevin is correct in a failure of process when pouring the babbit.I can tell by looking at the assembly it was done by a skilled hand.Is there a point in the babbit process where the actual composition of the babbit can be compromised?or is it as simple as contamination of the tinned bearing cap prior to pouring?

[Tom Wesenberg]

Counterweights are to stop the crankshaft from wanting to bend (whip) due to the heavy weight off the centerline of the crankshaft. This is one of the Model A's shortfalls.

Adding counterweights doesn't mean you need to lighten the flywheel, and I don't plan to lighten mine when I add the weights I bought from Dan Price. You are right that the added weight will help dampen vibrations.

That failed babbit may have been a bad mix or poured at the wrong temp, etc.

[Railcarmover]

I ran a full weight flywheel with a VW engine I balanced and counterbalanced.I was cautioned against it by the speed folks but found a fantastically smooth running engine,shifts smoother too..the extra mass improves drivability. I plan on using two single barrel down drafts,touring cam.mechanical advance distributor and high compression head in this build so a little 'zip' loss is acceptable to me..

I've seen videos of babbit pouring,they used a torch to flow the babbit..is their a proper temp to pour at? do they use a kiln to heat it?

[Railcarmover]

I also went with welded counterweights instead of a chinese crank..too many failure of SCAT cranks in the VW world,Wolfsburg metalugy.like Rouge metallugy is superior..does anyone sell a welded counterweighted A crank?or do you have to buy the weights and get them done?

[wensum]

I've had a welded counterweight crank crack. I'm not sure whether it was caused by the welding weakening the crank or by poor regrinding with ineffective radii?
I've now got a Burlington crank installed and so far no problems despite some members suggesting concern over the quality of the material.
The motor cruises at 60mph doing 1670rpm with the 41% F150 gearbox overdrive.
Keith

[Kevin in NJ]

FWIW, Ford produced a counter balanced crank for the A for use in grain body trucks.

They were run full out racing to get the grain to the silos for best profit.

They were shrunk on weights. The inner weights were a larger ID then the outer weights. They were heated and put in place and left to cool. They were not welded.

[Patrick L.]

Pre-detonation ?

There is pre-ignition and detonation. Two different critters.

Who do you think does the best babbitt work on the east coast ?

[wmws]

Schwalm's/Ora Landis

[Bob C]

Originally Posted by Kevin in NJ

FWIW, Ford produced a counter balanced crank for the A for use in grain body trucks.

They were run full out racing to get the grain to the silos for best profit.

They were shrunk on weights. The inner weights were a larger ID then the outer weights. They were heated and put in place and left to cool. They were not welded.

I've heard other people say this yet there is nothing in the parts books,
Service Bulletins or Service Letters. How about a part number or blue print.

Bob

[ursus]

If anything, the two photos in this posting are a great illustration of the versatility of poured babbitt bearings. The crankshaft looks fine yet it was running on a fragmented skein of failed babbitt. Hard to believe, but true.

[updraught]

A complete VW engine would be lighter than a Model A flywheel?

[P.S.]

Running a full weight flywheel with a counterbalanced crank on my 31 tudor. It runs great! I agree with Tom on this.

[Railcarmover]

Its a consensus. I spoke to a friend and he agrees with Kevin in NJ.It appears the failure is totally related to the babbit not adhering to the tinning. I'm still in good shape,I've got a good basis for repair,the engine has low hours on the build,I can save the cam and valve train,and not need to get the seats cut..Crank is probably still good,Ill have to measure it out.Block has been hot tanked and painted with glyptol.

Once I pull the pistons and measure the bores Ill know if it needs to be cut,If i get lucky I'll hone and ring it.. I might just get away with cutting for insert bearings and build,not bad for a few hours of fabrication eh?

[Railcarmover]

Originally Posted by wensum

I've had a welded counterweight crank crack. I'm not sure whether it was caused by the welding weakening the crank or by poor regrinding with ineffective radii?
I've now got a Burlington crank installed and so far no problems despite some members suggesting concern over the quality of the material.
The motor cruises at 60mph doing 1670rpm with the 41% F150 gearbox overdrive.
Keith

I could fill pages with photos of failed chinese crankshafts..



just say the word..

[Tom Wesenberg]

What make of engine is that broken crank from?

[denniskliesen]

When I worked on big trucks and construction equipment years ago I saw a lot of broken crankshafts. Some engines are just known to do it if they were ran at too low a RPM, (Cummins). Some engines if they had a bent or not straight crank would struggle for power, (Cat 3408). A lot of crankshaft failures were the result of a bad damper on the front of the crankshaft, (Cummins). Some dampers were oil filled and would leak, (Cummins). It amazes me how seldom you hear of a broken crankshaft in a Model A engine given the problem with the center main bearing failure. Haven given a lot of thought about this flywheel lightening, I don't think I'd want anymore taken off the flywheel then the difference in a stock Model A crank and a counterbalanced crank. And everything would have to be balanced. It bothers me whenever I see an engine with the pan off and 2 rods with the same number. To me it wouldn't cost too much to remove the numbers and renumber in correct location when it was rebuilt. I saw a lot of factory flaws also, casting flash in the cylinder head causing over heating problem, somebody forgetting to install the valve stem seals. Huh, what are those?

[H. L. Chauvin]

For many years, many in any business have noticed that no matter what type of work we are engaged in, if we concentrate on trying to master what we are doing, charge descent prices, and treat clients and customers with respect, we will always have more work than we can handle in just correcting what others continue to screw up with their carelessness and mediocre final results.

Works not just with good Model A engine re-builders; but also for plastic surgeons, cosmetic dentist, locksmiths, roofers, electricians, mechanics, and yes .... even bird dog trainers.

[Railcarmover]

Originally Posted by Tom Wesenberg

What make of engine is that broken crank from?

SCAT cranks in Vw engines,its a common occurrence.

In my opinion balancing is critical for engine and drivetrain life.Adding rotating mass like counterbalancing can be offset by flywheel lightening but if your not building for speed why?the additional mass has a dampening effect of its own.Kinetic energy is stored in rotating mass,to translate that into operator terms more kinetic energy means smoother clutch function and shifting,torque transfer impulse is moderated by the weight.

The engine I first worked on as a boy,that propelled me into a career, has taught an old dog a new trick.Till the last week i never knew babbit can de-laminate from tinning..that reason alone has changed my mind about babbit and precision insert bearings,Ive never seen this type of failure from inserts.

To add to Mr.Chauvins axiom,a customer trained in the use of measuring tools will rarely fall victim to slipshod engine builder practices..unless such provider hasn't mastered pouring bearings,you cant catch that mistake prior to failure.

[Patrick L.]

Originally Posted by wmws

Schwalm's/Ora Landis

Thats kinda what I think I'm leaning towards. It appears they do a proper job and have been adding counter weights for quite awhile.

[Patrick L.]

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I'm one that happens to like the heavy flywheel but have always heard that at least 12# needs to be cut from it when adding counter weights. Just another ole wives tale I guess.

[40 Deluxe]

Originally Posted by Railcarmover

SCAT cranks in Vw engines,its a common occurrence.

In my opinion balancing is critical for engine and drivetrain life.Adding rotating mass like counterbalancing can be offset by flywheel lightening but if your not building for speed why?the additional mass has a dampening effect of its own.Kinetic energy is stored in rotating mass,to translate that into operator terms more kinetic energy means smoother clutch function and shifting,torque transfer impulse is moderated by the weight.

Food for thought while eating breakfast: A heavy flywheel has a dampening effect, stores kinetic energy, and smooths out firing impulses. The thing is, each firing impulse tends to briefly speed up the crankshaft but that heavy flywheel prevents this, so something has to give! What is the result? Torsional twist, or flex, of the crankshaft. So a heavy flywheel stresses the crank more than a light one. It's not just the weight, it's 4 cylinders each trying to speed up the crank while that big flywheel resists.

[Tom Wesenberg]

Originally Posted by 40 Deluxe

Food for thought while eating breakfast: A heavy flywheel has a dampening effect, stores kinetic energy, and smooths out firing impulses. The thing is, each firing impulse tends to briefly speed up the crankshaft but that heavy flywheel prevents this, so something has to give! What is the result? Torsional twist, or flex, of the crankshaft. So a heavy flywheel stresses the crank more than a light one. It's not just the weight, it's 4 cylinders each trying to speed up the crank while that big flywheel resists.

Yep, what we need is a spring center flywheel, like the clutch disc.

[H. L. Chauvin]

Possible Most Ingenious Model A Engine Balancing Statement of the Year:

"The spring provided on the bottom of the Model A oil pump was carefully designed to absorb all Model A engine vibrations!"

[Railcarmover]

Originally Posted by 40 Deluxe

Food for thought while eating breakfast: A heavy flywheel has a dampening effect, stores kinetic energy, and smooths out firing impulses. The thing is, each firing impulse tends to briefly speed up the crankshaft but that heavy flywheel prevents this, so something has to give! What is the result? Torsional twist, or flex, of the crankshaft. So a heavy flywheel stresses the crank more than a light one. It's not just the weight, it's 4 cylinders each trying to speed up the crank while that big flywheel resists.

It not prevention of impulse,its a moderation of impulse,20 pounds of counter reaction against torque..the additional 'drag' has its greatest impact on the first revolution,but like a hit and miss engine,as it fires continuously the momentum generated by the mass of the flywheel dampen the impulse further.. basically Ill stipulate to initial crankshaft stress due to spinning the larger mass,but a counter acting reduction of stress as opposed to a lighter flywheel when running.

[wensum]

Thanks Railcarmover, You've just severely dented my feelings about the reliability of my motor which has all new components in it.
We'll just have to keep our fingers crossed every time we use it!
Cheers
Keith