Can you run an A wide open?

[Kohnke Rebabbitting]

Originally Posted by J Franklin

I have heard that one weakness of thick babbit is the fact that it keeps heat from dissipating through the steel of the rod which is a better conductor of heat. Fact or fiction? I don't know.

Heat conductivity is the same on a thin piece of babbitt, as it is on a thick wall piece of babbitt. A thick, or thin piece of brass will get hot fast when you grind on it, the thick one just takes a minute longer. Now the place where you loose heat transfer is where the babbitt meets the bearing shell. Cast iron has to be CORRECTLY peened, and steel CORRECTLY tinned, BUT the babbitt has to be stuck to the tinning, in which many places putting out bearings, are not. The OIL behind the bearing is what cuts down heat transfer, as OIL is not a good conductor, not the thickness of the babbitt, or the thickness of the shell. you need babbitt metal, to shell metal contact ((( 100%))), on a tinned, or peened bearing, or it will fail before its time. Just because you tin a bearing shell, that does NOT mean it stuck, when it cooled. If it didn't, the babbitt will push in, and out to the shell, and bust up, that also goes for cast iron pouring. feed back anyone, thanks Herm

[Kevin in NJ]

Balancing was specified on the crank print and heavily touted in the book "Know Your Model A Ford" and in the dealer sales literature recent published in the 'Restorer'.

I do not have the crank print handy, but I believe 1/4oz dynamically was the limit.

The rod print specs a specific weight +-1 gram on each end.

I have heard the pistons were supposed to be done down to a few grams each, but I do not have documentation.

The flywheel was balanced, but I am not 100% if it was done dynamically.

One other tid bit. I was reading something where they were explaining the machine that balanced the cranks and how accurate the machine could be. It could balance the crank better than Fords spec.

An interesting aside. My brother was taking down a flywheel and found a fairly large void in the casting. Opposite the void was a fairly large balance hole drilled into the edge.

[George Miller]

Originally Posted by George Miller
Re: Can you run an A wide open?
Quote:
Originally Posted by George Miller
If you ran a new car for long periods of time wide open it would not last.

Of course I know all that. My point is you can not run any engine wide open for long periods of time.

Tom I would have to see that to believe it. just because it is written does not make it true.
If engine could run wide open for ever, how come NASCAR engines have to be rebuilt after ever race.

[V4F]

i ran mine out yesterday . about 75 mph , but its the first & only time ill do it . not comfortable for me or my car at that speed ................ me & my car love 55-60 mph . ....... steve

[Patrick L.]

Herm , I'm not a babbitt guy, never did it.. But, I've installed my share of inserts and one of my pet peeves is to watch someone dunk the shell/insert into a puddle of oil and stick it in the block/rod/cap..That drives me nutz.. Regardless, a bearing is a bearing isn't it..

[Kohnke Rebabbitting]

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Originally Posted by Patrick L.

Herm , I'm not a babbitt guy, never did it.. But, I've installed my share of inserts and one of my pet peeves is to watch someone dunk the shell/insert into a puddle of oil and stick it in the block/rod/cap..That drives me nutz.. Regardless, a bearing is a bearing isn't it..

Yup, your right Patrick, sure don't need any oil behind any bearing. Babbitt, or modern insert, if they hold up, there good to go. thanks Herm.

[Kohnke Rebabbitting]

Originally Posted by Kevin in NJ

Balancing was specified on the crank print and heavily touted in the book "Know Your Model A Ford" and in the dealer sales literature recent published in the 'Restorer'.

I do not have the crank print handy, but I believe 1/4oz dynamically was the limit.

The rod print specs a specific weight +-1 gram on each end.

I have heard the pistons were supposed to be done down to a few grams each, but I do not have documentation.

The flywheel was balanced, but I am not 100% if it was done dynamically.

One other tid bit. I was reading something where they were explaining the machine that balanced the cranks and how accurate the machine could be. It could balance the crank better than Fords spec.

An interesting aside. My brother was taking down a flywheel and found a fairly large void in the casting. Opposite the void was a fairly large balance hole drilled into the edge.

Kev, the only reason I asked, is with the A's we have rebuilt, and all the spun rod sets we sold, and balanced in sets, and we started with a set that each rod was the same weight, as we would do about 500 each time to a batch. I never found any thing to make me think that any of the rods were balanced, they had no metal removal marks, and they were along ways off, for 0 balance. The cranks are drilled, but not zeroed. The flywheels, the same thing here, cut down about 100??? flywheels, I'am guessing about 30?? had casting flaws. But rebalance, and grind and all is well. The flywheels that we balanced in the past, alot were 12, to 23 grams out. thanks Kev, Herm.

[MrTube]

Kohnke Rebabbitting. I may have missed it if you said it but, In your opinion is it fine to run the A engine wide open at 2800-3K rpms or not?

I assume it will shorten the engines life (as with ANY engine) but I doubt it would do any real harm assuming everything is in proper working order?


In regards to sudden RPM changes damaging engines, We used to have a family friend who loved to rev his engines constantly. He felt it impressed people. At any rate, on one of engines the timing chain jumped a tooth with only 30,000 miles on it. It was always assumed the extreme wear on the chain was from him constantly reving the engine, forcing it to suddenly speed up and slow down the cam. This was on a 1960s chevy smallblock (327 I think) my dad had built for him.

[stautz]

50,000 miles on a Model A is like 150,000 miles, maybe 200,000 miles, on a car today. I drive with my foot on the floor most of the time because its more fun and I'm sure that's how the kids drove their parents' Model A.

[Larry Brumfield]

Originally Posted by Kohnke Rebabbitting

Another question Larry, did you get your vast knowledge of thick babbitt failing from remanufacturing babbitt bearings in your rebabbitting business, 6 to 7 days a week, for the last 42 years, or are you just repeating some old timers opinions, that you heard at swap meets saying that thick babbitt won't ever work. I will guarantee if thick babbitt fails, it isn't from any thickness. If babbitt is compressing under load, you have a bearing that has way to much clearance, has nothing to do with thickness. The same to much clearance that would compress a thick wall bearing, will also compress a thin wall bearing at the same rate, and that is a fact Jack, or I mean Larry. Ok, lets hear it, thanks Herm.

Sorry Jack ..... or is it Gomer? .... I mean Herm.... I disagree with your view on thick babbitt.

Also, that 42 year comment doesn't necessarily impress anybody. On the other hand, if your knowledge of babbitt bearings has been increasing DAILY for 42 years then you must be a smart s.o.b........ More than likely though you learned most of what you know in about 5 years or so ... so that means you have only 5 years experience 8.4 TIMES OVER!

In my opinion, the thinner the babbitt the stronger. Now depending on the differences it may not be greatly significant in all cases or even be a problem but it's still there. If an undersized crank is off center a bit too much or slightly distorted in its operation for one reason or another; like so many of them are; the crank will tend to beat and compress the thicker soft babbitt more than the thinner by comparison and create excessive clearance possibly leading to bearing failure.

Of course if a bearing fails you can bet that it won't be the fault of the engine rebuilder!

Just my experience ..... stated in the same manner as you.


Larry B.

[29RPU]

Man, this is awesome. Not only did a thread I start gain so much popularity, zig-zag a bit off topic, AND get some great opinions about running an A wide open, but there are little verbal scuffles going on in here as well! Who could ask for anything more. All we need now is some virtual beer. Thanks guys!

[MrTube]

Originally Posted by 29RPU

Man, this is awesome. Not only did a thread I start gain so much popularity, zig-zag a bit off topic, AND get some great opinions about running an A wide open, but there are little verbal scuffles going on in here as well! Who could ask for anything more. All we need now is some virtual beer. Thanks guys!

Yea... Look what you did.. mom always said not to play ball in the house...

The only opinion I have on thick babbit is, obviously there were things considered in designing the engine and they for SOME odd reason picked the original thickness and I would have to assume deviating from this thickness in any direction could and most likely would cause problems. Again, this is just going on my usual assumption that all things are done for a reason (and they usually are).

[Pete]

"In my opinion, the thinner the babbitt the stronger and the thicker the softer. Now depending on the differences it may not be greatly significant in all cases or even be a problem but it's still there." (Larry Brumfield)

I just happened across this thread so I guess I missed most of the fun.
Larry is right according to the laws of physics..That is one reason modern shell bearings only have babbit .0002 thick.
Actually a given bearing material will deflect at the same RATE for different thicknesses but the thicker one will deflect farther with the same load thus causing more movement in the total assembly..This movement caused by the reciprocating forces equates to less bearing life.
The bearings in a model A engine are so lightly loaded that almost any thickness would work though.

[Marco Tahtaras]

Originally Posted by Kohnke Rebabbitting

Kev, the only reason I asked, is with the A's we have rebuilt, and all the spun rod sets we sold, and balanced in sets, and we started with a set that each rod was the same weight, as we would do about 500 each time to a batch. I never found any thing to make me think that any of the rods were balanced, they had no metal removal marks, and they were along ways off, for 0 balance. The cranks are drilled, but not zeroed. The flywheels, the same thing here, cut down about 100??? flywheels, I'am guessing about 30?? had casting flaws. But rebalance, and grind and all is well. The flywheels that we balanced in the past, alot were 12, to 23 grams out. thanks Kev, Herm.

Hi Herm,

You were looking in the wrong place based on modern methods. Note the circumferential grind marks on the edges of both ends of the connecting rod. This was the last stage and when you study original rods you will find no two identical. The amount of "meat" removed is based on the particular weight removal requirements. I'd love to see the original machine. The machine certainly must have been automatic like the piston balancing machine which weighed the shavings and quit when the shavings weighed the same amount as the determined excessive weight.

At the beginning of production Ford balanced connecting rods in sets of four. They made it very clear to the dealers that they MUST replace connecting rods in complete sets to maintain the proper balance. Ford worked out their production / balancing methods and began making ALL connecting rods the same weight beginning April 24, 1928. They began providing the same for service May 10, 1928.

[Kevin in NJ]

Here are the crank specs off the drawing.

[Kurt in NJ]

Herm, I think that the method used to balance the rods is the machining on the outside of both the big end, and the small end, they all seem to be very close to the same at the edge, but the depth, and the angle is somewhat different, with the thicker forgings having more machining ---the same method was carried over to the V8 flathead rods.

The Ford blueprint shows a weight spec of 198 grams +-1 for the small end, and 512 +- 1 for the big end.

I had a boxed NOS set of B rods, they weighed out within 1/2 gram of each other at both ends.

The crankshaft print has a balance spec--"shaft must be in balance dynamically within 3oz inch at any 1 point of reference, shaft must be in balance statically within 3 oz inch"

[Bob Johnson]

Here are two rods from the same engine. Notice the difference in the amount of material that has been removed at each end.

Bob

[Kohnke Rebabbitting]

Originally Posted by Larry Brumfield

Sorry Jack ..... or is it Gomer? .... I mean Herm.... I disagree with your view on thick babbitt.

Also, that 42 year comment doesn't necessarily impress anybody. On the other hand, if your knowledge of babbitt bearings has been increasing DAILY for 42 years then you must be a smart s.o.b........ More than likely though you learned most of what you know in about 5 years or so ... so that means you have only 5 years experience 8.4 TIMES OVER!

In my opinion, the thinner the babbitt the stronger. Now depending on the differences it may not be greatly significant in all cases or even be a problem but it's still there. If an undersized crank is off center a bit too much or slightly distorted in its operation for one reason or another; like so many of them are; the crank will tend to beat and compress the thicker soft babbitt more than the thinner by comparison and create excessive clearance possibly leading to bearing failure.

Of course if a bearing fails you can bet that it won't be the fault of the engine rebuilder!

Just my experience ..... stated in the same manner as you.


Larry B.

Yo, Larry, I am sorry the 42 year comment didn't do anything for you, you'll be glad to know I tried it on my girl friend this afternoon, and it didn't do anything for her either, so I went down my list of known workable things, and found one she did like. I was going to thank you for the smart S.O.B. comment, but after I reread it a couple of times, I realized that you probably forgot a word in that sentence. You are wrong about learning what I know in 5 years, it was more like two years, I was lucky to have a Clawson & Bals babbitt trouble shooter teach me, and he sold me all Clawson & Bals machines, that he was going to use, but didn't get to after his retirement, from then on the learning part is mostly being able to tell when a pour is good, as every bearing pours different, temperature, to fast, to slow, cool to fast, not fast enough ect. In your opinion Larry the thinner the babbitt the better, and that is just what it is, Your Opinion, has nothing to do with Reality. If we were not to rebuild thick babbitt bearings, 60% of the bearings we do would never let there engine run again. Most of the cars, tractors, and machinery from 1900 to into the 1920's were real thick babbitt, and or thick babbitted shells. the big old tractors, some of them 3/8, to 1/2 inch babbitt thickness in rods and mains, and they are no better or worse than the model A. When babbitt thickness is cut, in factory engine building, it was mostly done to save money. 216's Chevy rods, from 1937 to 1953, have about .010 wall thickness of babbitt, and that works just fine, as they were all done at the Chevy factory, or a place they farmed them out to. The problem with rebuilding them the first time, is that you can't hit the same hole, as it were. So the 216's are bored to 100 thousands over standard bore with out babbitt. so there goes your thick babbitt that won't work again, BUT IT DOES. The babbitt wall now is .060 thousands thick instead of .010 thousands in a factory untouched rod. So Larry, in 42 years, and NO bad bearings EVER, in your experience what am I doing wrong. As far as an engine rebuilder ever being at fault, we stand behind every bearing we do. Babbitt bearing are just like insert bearings, in that if you have a bearing blow, weather babbitt, or insert you normally can tell why, just like an insert book, that has many pictures showing inserts, and there cause of failure. As far as an engine rebuilder never being at fault, the owner has to take some of the fault, as if his wife is a real you now what, just remember he picked her. Thanks Larry Jack, Gomer.

[Kohnke Rebabbitting]

Originally Posted by MrTube

Kohnke Rebabbitting. I may have missed it if you said it but, In your opinion is it fine to run the A engine wide open at 2800-3K rpms or not?

I assume it will shorten the engines life (as with ANY engine) but I doubt it would do any real harm assuming everything is in proper working order?


In regards to sudden RPM changes damaging engines, We used to have a family friend who loved to rev his engines constantly. He felt it impressed people. At any rate, on one of engines the timing chain jumped a tooth with only 30,000 miles on it. It was always assumed the extreme wear on the chain was from him constantly reving the engine, forcing it to suddenly speed up and slow down the cam. This was on a 1960s chevy smallblock (327 I think) my dad had built for him.

Mr. Tube, I guess I wouldn't want to say much about wide open,VS not, I think what I would do if I had an A yet, is put in an overdrive, and keep the R.P.M's down to a 45 stock speed, they have plenty of power to handle it. thanks Herm.

[Kohnke Rebabbitting]

Originally Posted by Kurt in NJ

Herm, I think that the method used to balance the rods is the machining on the outside of both the big end, and the small end, they all seem to be very close to the same at the edge, but the depth, and the angle is somewhat different, with the thicker forgings having more machining ---the same method was carried over to the V8 flathead rods.

The Ford blueprint shows a weight spec of 198 grams +-1 for the small end, and 512 +- 1 for the big end.

I had a boxed NOS set of B rods, they weighed out within 1/2 gram of each other at both ends.

The crankshaft print has a balance spec--"shaft must be in balance dynamically within 3oz inch at any 1 point of reference, shaft must be in balance statically within 3 oz inch"

Kurt, I have had many sets of used rods , the owners said were original to there car, but you know how that goes. I know about the machining on both ends of the rods, but never fully under stood the purpose, as when we would get in so called sets to spin for a balance set, I would put them on the balancer, and have never found a balanced set. That was with used babbitt, no babbitt, and or new machined babbitt. When we spun 500 rods, pre machine to .060 under, weigh all 500, lay them in long lines, and pick them for total weight. now you have many sets that each rod weighs the same, if they were balanced that close at the factory, why were they such a long ways off when you went to balance them. I don't know. They all had the same weight of shims, and rod nuts. The Model B rods, we only had about 250 cores, and we got good sets out of fewer rods, but they were closer to balance. The Model T rods were the pits to balance. Thanks Herm