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scott12180

Two ball bearing crankshafts

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Hi --- Perhaps this is the wrong forum, but could anyone shed some light on the soundness of early engines that used ball bearings for their crankshafts?

The Chalmers of around 1910-1912 or so used two ball bearings for their four cylinder engines. To me, ball bearings might be OK for light loads and VERY clean oil, but two main bearings in a big four is pretty scary.

Any thoughts? Chalmers was a rather popular car with a decent reputation, that I can determine.

--Scott

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Autocar used large ball bearings to support their 4 cylinder crankshafts in their large trucks. We restored a '28 with such a setup and while the truck had obviously travelled many, many thousands of miles, enough to wear the spring shackle bolts from 3/4" to less than 1/4", these "main" bearings showed little sign of wear. Admittedly this was a relatively slow turning engine.

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International also used a ball-bearing crank in its four-cylinder engines in the teens & twenties, one BB at each end - a "two-main" engine.

AFAIK, these were robust engines, and IHC probably used the same construction in their agricultural engines.

I believe Stutz also used ball-bearings on their four-cylinder mains... ?

I think the issue had more to do with "crankshaft whip" at higher RPMs, due to lack of support at the center... maybe not an issue when engines didn't spin more than 2000 rpms...

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Not really car related but the International T20 tractor has a four cyl, two ball bearing crankshaft, they seem to last forever. I bought my first (1935) T20 about 30 years ago and put a lot of hours on it. The tracks and sprockets wore out so it's parked in the barn now, but the engine never missed a beat. On the IHC T20s the two ball bearings are quite large - about 5 or 6 inches outside diameter. These bearings give the engine a unique sound. I'm not sure if it's normal or if the ball bearings are getting worn. But other than the sound of large ball bearings rolling along, no problems at all.

I have three of the T20s. I found my second one in a field about 20 years ago. The engine was froze up and I traded the farmer an old Chevy transmission for it. I took the engine apart but didn't touche the ball bearings, because they looked good. For a little extra power, I machined about .200" off the head to increase compression. I also turned up the governor to 1500 Rpm from the factory setting of 1200. It pulls great and I use it every spring.

Here it is in action

T20April.jpg

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Dean H - VERY COOL !!! :D:cool:

I would love to have a McCormick 10-20 or 10-30 some day ! ( On steel or rubber)

I had an early Farmall A as a kid - crank start, mag-only... s/n FAA-1829. Tough old machine !

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Duesenberg used 2 ball bearings on their walking beam, 4 cylinder engine. This was a high performance engine from the teens. 302 cubic inches and up to 86HP.

One ball bearing at each end of the crankshaft. There was 1/8" clearance between the crank and the crankcase, and it was common to tear the engine down and find score marks in the crankcase where the crankshaft hit it. Especially those used for racing.

Edited by Rusty_OToole (see edit history)

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Stutz used 3 ball bearings, they had to make the crankshaft in 2 pieces to get the 3d bearing in. The crankshaft was split in the middle, they put the bearing on then bolted the 2 halves together with a taper fit.

Harley Davidson and other motorcycle crankshafts were built up the same way. If the crank was taken down and bearings replaced, you had to true up the crank when you put it together.

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100 MPH on3 inch wide cotton cord tires. No roll bar no seat belts and your crankshaft whipping around like a skipping rope. Those were the days.

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The ball bearing crankshaft would be the least of your worries. Given the type of oil they had back then, and the sketchy lubrication systems and no filters I expect the ball bearings would outlast babbitt bearings in hard use. Ball bearings will thrive on just a few drops of oil once in a while. No doubt that is why they were used in heavy duty, tractor and racing engines.

They were expensive, noisy and made it hard to install more than 2 mains. The reduced friction was a very small reason to use them. Once they figured out how to make plain bearing crankshafts stand up the ball bearings went out of favor.

Incidentally I would expect to find a ball bearing at the rear of the engine, to take the end thrust when the clutch was disengaged. But a roller bearing at the front of the engine to allow for heat expansion.

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Austin Sevens used two ball bearing crankshafts - ball at one end roller at the other. The engines are small, just 750 cc 4 cylinder side valve, but they readily accepted high performance modifications and were used in racing cars in England probably into the '40's. The racing engines were often supercharged and some were converted to twin overhead camshafts. These engines normally ran 9,400 rpm and could withstand as much as 12,000 using the ball bearings.

Terry

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I'd forgotten the Austin 7. The first Lotus was an Austin 7 Special built by Colin Chapman in his spare time, in the early 50s.

There were many Austin 7 specials on English race tracks in those days.

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Many modern two-stroke engines use ball bearing mains also. They rev very high and last a long time.

I believe Lawn-Boy used needle-bearings on their mains "forever"... at least on their 2-stroke engines.

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The story about the crank bending enough to hit the crankcase came from a book published in the 60s or 70s. Good to know it is an old wive's tale.

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On any 4 cylinder engine there is going to be a secondary vibration at twice engine speed. At least I think that's how it works. In any case there is a vibration that cannot be balanced out without separate balance shafts.

I know this is a problem today with straight 4 cylinder engines bigger than 2 liters. I have often wondered about the big 4's of the WW1 era. Did they have a big vibration period to match their size? Or did they not rev high enough to pose a problem?

Of course this would not matter in a race car, I am thinking of luxury cars that used the big 4 cylinder engine.

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T-head,

In his memior "The Birth of Chrysler Corporation, and its Engineering Legacy", Carl Breer talks about his early days (pre-1920) at Chalmers and then Studebaker, and I believe he spends a few paragraphs on vibration / crank problems with the Studebaker Big Six... if I remember correctly , this issue was related to "torsional vibration" (nowadays eliminated by the "harmonic blanacer"?).

Regards,

De Soto Frank

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The 4 cylinder and six cylinder vibration are completely different.

The 4 cylinder has good primary balance but there is a secondary vibration at twice engine speed.

A straight six has perfect primary and secondary balance. Their problem is that the crankshaft is so long it can have a harmonic period that is within the RPM range of the engine.

For example a 2.6 liter Austin Healey is limited to no more than 6000 RPM because at 6200 the speed matches the vibration period of the crankshaft and it will snap.

This is the same phenomenon that causes a wine glass to shatter if a singer hits just the right note.

The 4 cylinder 2.6 liter Austin Healey never had this problem because its crankshaft, being shorter, had a vibration period of 14000 RPM and the engine could never rev anywhere near that high.

Incidentally some racers ran Austin Healey sixes at higher speeds but they knew they had to power through the vibration period quickly before it snapped the crank.

The early sixes of the pre WW1 period had very long crankshafts with a low vibration period. Napier, and early maker of sixes, called it "the power rattle".

Frederick Lanchester invented the first vibration damper for crankshafts in 1906. This cured the problem. Cars still use a vibration damper, that is why the crankshaft pulley is mounted in rubber.

You can hang up a crankshaft and hit it with a hammer and it will ring like a bell. The higher the note the higher the vibration period RPM.

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Just to qualify the bit about Napier's torsional vibration periods, I think you will find it was S F Edge the promoter-salesman (and later pig farmer) who attached the "power rattle" title to this. This is a classical example of what we now call "spin", as frequently used by politicians. Napier was too good an engineer and not of a mind to dissemble. His focus was more on overcoming problems than talking them down. I had three friends with 6 cylinder Napiers. Arthur Lang had a 1907 4"bore type 20 which is probably restored now by a later owner.

Alan Fitgerald had a 65hp which was about double the engine size of Arthur's 40hp. Alan eventually sold that to someone who made it useable. I saw it running at low revs at a hillclimb; but I cannot recall whether it was sent up the hill.

Bob Chamberlain built a very authentic re-creation of their first big 6 cylinder racing car L48. Bob copied A J Rowledge's original design notebooks on the car and drew everything himself. The original cylinder barrels were such that he decided to conserve them, and I was disappointed that he did notmake the replacements with paper-thin electro-deposited water jackets as had the originals. It was probably for considerations of rigidity that he made barrels using cores to cast them with conventional water jackets. The aluminium alloy pistons he made for it were very much lighter than the cast iron originals; so the diminished reciprocating masses possibly helped th moderate or shift the vibration periods. Bob and his brother had been making a few pistons, but in the mid 1930's decided to do the job properly by buying a licence from RayDay. General Motors Holden was the largest customer for Rolloy pistons for many years.

My Napier I am restoring now is a 4 cylinder with the flywheel out the front. The diameter of big end and mains is very generous, so I doubt they had torsional vibration problems with it or the 30hp six that was of similar design. my 4 cyl is the earliest car I have seen with a fullflow oil filter. Jack Nelson went for a ride in a 30 in UK in the mid 1960's, and he was very impressed with how well it perfomed cumfortably in heavy traffic.

The only Stutz engines which had main bearing ball races were the "White Squadron" OHC cars just before US joined the conflict in WW1. One went to NZ and is still there.

The Rochester Duesenberg engines had a very different crankshaft to the racing engines. There are massive counterweights welded to the forged shaft, and my engine is very smooth at all revs. All the bearings are plain whitemetal pressure fed from the two mains. The oil pressure is much higher than usual for the era so the centre crankpins are supplied adequately. Engine torque is tremendous, and it will pull that 4 to 5 overdrive top gear on closed throttle about 100 yards from start at the house up about a 5 to 8 degree slope towards the workshop.

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Look at any racing 8 cylinder Bugatti from 1924-1932. Story say that these engines have to be re-rollered every 10thousand miles or so with undetacheable head....

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When you read the individual known records of the Bugatti cars here in Australia, (and this is all reseached and recorded by Bob King), it seems notable that a large percentage of cars went through a long series of change in ownership and change of registration. Geoff Fullard, a retired professional engineer about 30 miles from here, has owned, restored, and used over many decades a late 1920,s sports racing Bugatti which was raced by, among others , Hope Bartlett. (Bartlett's business in the early 20's was transporting tourist passengers between Katoomba and Jenolan Caves in the Blue Mountains west of Sydney using V8 Cadillacs. But he raced Bugattis, and his personal car was a 22/70 L-head Mercer Sporting.) Geoff had to make new cast aluminium "blade"wheels with their integral brake drums. He told be that Bugatti's engine lubrication system was faulty, and that he had to re-engineer that so it is effective and reliable. Now Geoff says that the major fault in Bugatti roller bearing cranks is that the diametar of the rollers is far too large for them to track correctly. Geoff and his brothers used Velocette motorcycles for years, which are totally reliable .

They use needle roller bearings: so Geoff re-engineered the bottom end of the Bugatti with needle rollers, which ended the rattle and the trouble.

There is no point in repeating what is printed authoritatively about Bugatti, who was autocratic and you might say, idiosyncratic. In 1984 I spoke to alan Powall after I got my A Duesenberg from Mexico through Ray Wolff, and got a copy of Fred Roe's Duesenberg book, against which i was able to check Powall's memory of 60 years before. He bought his Duesenberg from the factory in 1923 when he was 23.(Five weeks from order till handover.) He took the car to England and Europe before bringing it back to Melbourne where it still is. He was given an extensive guided tour of the estate by Bugatti himself, then sent out for a ride in one of their Type 30 racing cars with one of their racing drivers who just happened to turn up. When he returned to his car to leave, a team of mechanics and draftsmen had the cylinder head off, and a wheel off tho examine and draw the hydraulic brakes as well. Alan Powall became very annoyed again remembering and relating the event after so many decades. He said that Bugatti should have bought a Duesenberg himself if he wanted to study it; but what he did never did him any good. He said that Bugatti did not improve his engine design, and "he still used clothes-line wire to work his brakes"! Alan Powall was at work at his business when I called and met him, and he was listed in the Melbourne telephone book till the end of his nineties.

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