Driving speed for 32 Packard

[tbirdman]

I have been following the discussions on the board regarding babbitted rod bearings vs. inserts. I am going ahead and rebabbitting my rods for my engine rebuild. I know for Owen's 34 closed car, he drives around 50-55 and has plenty of miles on his babbitted rods. That car has a 4.69 rear end ratio. My 32 being open probably has a 4.41 rear end. Also I have 19" tires on my car vs 17" on Owen's which reduces the RPMs for given road speed.

I found some RPM data for a Packard with a 4.41 rear end and 19 inch times.

2219 RPM at 50 MPH

2441 RPM at 55 MPH

The RPM data came from a Packard service letter for the 8th series cars which used 7X19 tires and a 4 speed transmission.

These RPM seem reasonable to me if I keep the car speed between 50 and 55. I do not have a desire to drive faster than 55. One fact regarding speed is people drive slower in Oregon.

So without resorting to high speed gears which for the ones that are available would only reduce the RPMS by 10% or an overdrive (one day I may get) which is $$$, does it seem reasonable that I can drive max 55 MPH and with these RPMs not run into bearing issues.

[Guest 39Super8]

This is sure to be a very interesting educational thread. I myself pondered these same things a few years ago. I chose the fitment of new inserts. I think one Packard expert in particular will have much excellent advice and guidance for you.

Good Luck,

Jim

[West Peterson]

While I'm not an expert, I'd put money on a bet that if all you want to do is 50-55mph, you shouldn't have any concerns.

[Restorer32]

Ya know....modern insert bearings are simply shells that have been babbitted as part of their production process. Most rebabbitting shops use the same "babbitt" as in modern inserts. The shop we use uses the same "babbitt" as in my Dodge Turbo Diesel pick-em-up.

[tbirdman]

The reason I'm asking because i got a few club members who say I should get OD while I have a fresh engine. My retort is if I'm happy driving 50-55 that shouldn't hurt the engine. OD is only a neccessity if you want to start doing 60-70 . Who's smoking the crack?

[trimacar]

So, discussing babbitting always makes me think when it's melted, it's runny babbitt. But I digress, and I haven't even started.

Babbitt is a great bearing material (being softer than the steel of the crankshaft, and able to "absorb" oil), but a not so great heat dissipation material. That is, it will store heat and not conduct it well, so if babbitt is too thick, that bearing gets hot and hotter, develops cracks, and can begin to disintegrate. This is the reason that, the more undersize you go on a crank or rod bearing with pure babbitt, the greater the chance of failure of that bearing.

That is the principle behind using a steel shell, with a thin babbit surface. The babbit is a good bearing surface, the steel is a good heat conductor, and the heat goes away from the babbit.

So, many factors influence the life of the bearings. Speed of course is one (meaning either high road speed, causing more revolutions and thus greater linear speed of crank to bearing surface, or high engine speed caused by mentioned drive gearing, causing the same increased linear speed), but also thickness and quality/composition of the babbitt, tolerances, oil quality. All can contribute to failure of bearing, evidenced by micro-cracking, cracking, and finally separation (i.e. chunks of babbitt in your pan).

My point is that it's not just a simple "54 mph is fine, 55 mph is a no-no" type answer, and other factors must be considered.

I will say that I am of the opinion (and yes I know what that's worth) that the modern insert type bearing is the way to go, and both my Packard and Pierce have been converted to same.

[Guest 39Super8]

Ken,

My 320 equiped car felt wound out at 50 mph. When I put overdrive back in, it is totally different, basically loafing along at 50 / 55 and easily capable of 65.

Trimacar,

that is the best explination of insert v. Babbitt I have seen yet.

I am still waiting for one certain poster to clear this up, and somehow make about V-12's :-)

Edited December 17, 2009 by 39Super8 (see edit history)

[tbirdman]

My 32 384.5CI is not straining as it is only doing 2200 RPM at 50. I agree OD would reduce engine RPMs, but I believe the car is quite capable of running at 50-55 without needing a rebuild because of the babbitts letting go. It will be a ring and valve job the next time the engine is serviced (at least that's what I'm planning). And at 2K mile or so per year, I got quite a bit of runway before I will need to do that.

Edited December 17, 2009 by tbirdman (see edit history)

[Guest 39Super8]

Sounds like you understand the up's and down's of bearing choices and are comfortable with the MPH limits that will have to be lived with. I think you have answered your own question.

Enjoy,

Jim

[tbirdman]

Sounds like you understand the up's and down's of bearing choices and are comfortable with the MPH limits that will have to be lived with. I think you have answered your own question.

Enjoy,

Jim

So I guess my real question is where is the upper limit of RPMs you would want to limit a early 30s babbitted rod Packard?

[Guest 39Super8]

Ken,

<O:p</O:p

I guess the first question is what are the dimensions of the engine. In your case, 3.5” x 5” is one heck of a bore and stroke. My little 320 has a 3 3/16”th bore but shares the same 5” stroke. My thinking a few years back during my own questions much like the ones you have posed were RPM’s are the enemy. These long stroke monsters generate tremendous loads at high RPM’s. In my mind, based on some engine math I did at that time, and just how the engine felt and sounded, my conclusion in my own case was ideally 1900, and up to 2100 – 2200 sustained and bursts of 2300 – maybe 2400 in short servings. What Trimacar described is exactly the failure I observed in my own inserts as well as many other inserts / and babbited rods I looked at any chance I got. I truly think they had issues with the early insert rod bearing design, at least in the 320 engine.

<O:p</O:p

I will say this, the 28% overdrive makes the car so relaxed and pleasant. It’s just the feeling of not beating on the poor long stroke monster, but capitalizing on all that torque. I went for modern inserts and overdrive, and haven’t looked back yet.

<O:p</O:p

With all that said, these cars were driven at 50 / 55 MPH when new. The bearings lasted fairly well. Owen-Dyneto (Dave) has often cited that he operates his 34 at 50 /55 MPH and has 45,000 miles with little trouble. Other regulars here (with many different screen names) have professed dooms day proclamations concerning any car with babbited rods.

<O:p</O:p

Like I said, you have a good handle on this. You know how your car feels, and how hard the engine is spinning. If there is a sweet spot around 50, and you are comfortable with the babbited bearings, keep doing what you have been doing.

<O:p</O:p

Jim

[Rusty_OToole]

I wonder how much of the problems with babbitt bearings is due to sheer age and metal fatigue? I don't doubt they are flaking and failing now but I can't believe they were so weak when new.

[Guest RenegadeV8]

Trimacar in post #6 above gives an accurate analysis of the babbit. Additionaly and UNrelated to the bearings keep in mind that long stroke engines tend to create very fast piston speed. The fast piston speed causes faster ring/bore/piston wear especialy at high engine rpm.

My advice for anyone that wants to drive a long stroke engine at Interstate speeds of say 60- 70 mph and higher SUSTAINED speeds is to go with the insert bearings AND AN OVERDRIVE. Whatever it takes to keep the sustained engine rpm 2500 rpm or lower. The engine should have plenty of power to handle the overdrive at the lower rpm range.

My question: What is the cost difference between rebabbiting vs modification for the inserts?????

Edited December 18, 2009 by RenegadeV8 (see edit history)

[trimacar]

Hi- I agree with R-V8, the combination is a winner for the higher speeds for any length of time. I forgot to mention that my Pierce, in addition to the inserts, has an overdrive that was installed in the 1960's. I don't try to push it, but it sure makes those long stretches of road more enjoyable. My car was driven all over the south during the 60's and 70's, the fellow who owned it was based out of New Orleans, and didn't even own a trailer to my knowledge. The Pierce had the largest brakes of just about any car out there, so braking is not the issue that it is with some cars.

I had inserts installed in the rod bearings about 6 years ago, I think, time does funny things as you get older. At the time, a company in California did them for $125 each (x8 of course), which included machining, fitting, and building up of side of rod to fit journal. The engine has the babbitted mains that were replaced in 1960. There is so much surface area (9 main bearings), and they were in perfect shape, so I left them.

I'm not an expert on babbitt by any means, but also believe that it can age when submersed in oil, if the oil has impurities in it. Maybe someone else can chime in from a chemical side. Merry Christmas to all!

Edited December 19, 2009 by trimacar (see edit history)

[Rusty_OToole]

The old rule of thumb was a max sustained speed of 2500 feet per second piston speed. Over that, friction and wear rise rapidly.

Phil you are right feet per minute

Edited December 19, 2009 by Rusty_OToole (see edit history)

[Phils38cpe]

The old rule of thumb was a max sustained speed of 2500 feet per second piston speed. Over that, friction and wear rise rapidly.

I think that should be feet per MINUTE not second. But even at feet per min that would let my 38 282 motor cruise at a touch over 3400 RPM and that seems a mite high for sustained travel - 4.25" stroke

[Guest RenegadeV8]

I have a 4-1/2 inch stroke engine with 3-5/16 pistons ON ROLLER bearing crank assembly special raceing quality 'journals' and corrillo rods. It's an Indian m/c engine. I'm fully confident it will turn up to 3500 rpm sustained. Rarely sustain more than 2800 rpm tho.

THE PROBLEM is excessive ring/bore wear in about 3K to 5k miles or less. Cast pistons do not increase my confidence level any either. I've overhauled many of these engines including my own at least every 6 to 10 years.

So even once the lower end is beefed up to take sustained modern demand levels of rpm then the bore/rings/pistons are not suited to the higher piston speeds.

The flat head engines are rather ez and relatively cheap to ring and valve lap when needed on shorter intervals. BUT rebabbiting is NOT ez.

So it becomes a trade off between insert bearings along with maybe some micro-blueing of bore and pistons along with overdrive and large diameter wheels and tires to attain modern speed demands from the long stroke engines that were originaly designed for an entirely different era of driving demands.

[Guest RenegadeV8]

One thing i have found to be certain. Trying to drive open highway even at posted 55 mph speed limits becomes a bit disenchanting when i suddenly realize that i have become a moveing obstacle to most all others on the road running 10 miles over the limit. NOT UNCOMMON on open rural or desolate hiway.

[Restorer32]

A 1932 Packard 900 Convertible will do 80 mph on the Mass Turnpike when it is on fire and your wife is screaming and you are racing to an exit where you know there is a water hose.

[Packard8]

A 1932 Packard 900 Convertible will do 80 mph on the Mass Turnpike when it is on fire and your wife is screaming and you are racing to an exit where you know there is a water hose.

I'm sure the SWF (Screaming Wife Factor) adds another 1500 RPM and 20 MPH to the equation!

Good point about modern babbitt being much the same whether poured on the rods or brg shells.

As far as piston and brg wear on long stroke engines, the 6 Cyl. Cummins ISB (bore 4.02, stroke 4.72) 5.9L in marine trim will run continuously @ 3000+ RPM for the equivalent of 250,000 miles between overhauls.

I don't advocate pushing 70+ year old engines too hard, but if properly rebuilt to OEM tolerances and well balanced and filled with modern oil I think they are capable 55-60 cruising as long as the tires, chassis, brakes etc are up to snuff.

[Guest 39Super8]

Some very interesting replys.

Ken, let me ask you; what RPM do you feel is sustainable? do you feel 2450 @ 55 MPH is acceptable? I have never really seen anyone with this family of engine give a definitive redline, or cruise RPM, just lots of speculation.

[Ozstatman]

Posted this table for 8th Series over on PackardInfo.com - Packard Motor Car Information - Do you know how fast your 8th Series engine is turning? [Packard Forums - Pre-War (1899-1942)]

[Guest RenegadeV8]

Looking for a definitive answer would require either factory documentation or somekind of authorized dyno testing among a group of say a dozen sacrificial engines.

This thread among many other threads over the years seems to form a concensus that the range is 2200-2700 rpm. Call it 2500 rpm. This is not speculation. It is based on a variety of experiences, backgrounds and on the road testing over many miles and many years by many different people.

Until someone comes up with factory or dyno testing results then the 2500 rpm range (give or take 200 rpm) is the best u have to work with. Specualtion or no speculation.

[34PackardRoadsta]

Ken,

Given how much you drive the car, I would really encourage you to fit the crank with shell inserts. My 34 has studebaker inserts for that very reason. As others have pointed out, it really isn't rpms you need to worry about, but heat. Inserts are just a ton better at dissipating heat. Of course, modifying the rods to accept inserts is not cheap, but neither is getting them re-babbitted.

I know Dave Z has had great luck with babbitted bearings on his standard eight. We had less luck on our 34 super-eight before going to inserts. I don't know if this was due to the greater torque on the super-eight engine, or my mother was secretly drag racing . As always, your milage may vary!

Tom

[Guest 39Super8]

Mal,

Thanks for posting the PInfo. link. I missed that thread somehow. Great read.

Interesting perspective some have on maximum sustained RPM. I suppose at the end of the day, this is the sole choice of each car owner / operator. As for low gears v. tall gears, overdrive v. not, I just spent a couple hours with the wife and friends in our super 8 motoring through a neighborhood on a hill side looking at christmas lights. The long stroke and 4:36 gears made for a most pleasent experience. When finished with our tour of the neighborhood, into overdrive and on the freeway at 60ish with no strain. In my case, 39 was the first year overdrive was avaliable. It is a relativly easy and inexpensive proposition. In Ken's case it was not an avaliable option, and would require expense and much fabrication. Taller rear gears would be fine on the highway, but that wonderful low speed stump pulling torque would be gone.

Tough choice, but it sounds like Ken already has a plan.

[Guest RenegadeV8]

Very little has ever been discussed over the years about the 2 speed Columbia axle. Perhaps an alternative or even addition to the overdrive or other plans.

[Guest BillP]

This has been talked heavily in the past. There are (occasionally warring) camps eager to espouse their views. Although I don't profess to know it all, I have done some research and put some thought into the matter. For those not familiar with the, eh...discussions...of a few years ago, here it is in a nutshell: In the case of those not in agreement with me, be it known that in making their pathetic and small-minded arguments, dependence on obfuscation, myth, voodoo and bluster are the sole and over-riding elements used. That and a lot of unnecessary quotation marks. I and a few other enlightened souls, however, see the truth. Having thus established my impartiality and bona fides as an expert, I now proceed to advise on the matter at hand.

I have a 34 like Owen's; so far as I can tell, it has never been re-babbitted. It's essentially an original, one-owner car with about 65,000 miles. Admittedly, one swallow does not a summer make, but it is interesting to note that it continues to conduct itself as intended.

ONE big reason for the bad rap (pun intended) that poured bearings get is the very poor quality oil used back then, compared to modern technology oil. Further, there were two periods in a pre-war car's life when it was most at risk for damage: during the war itself, when maintenance and good supplies were scarce and at that time when it was simply a used car of little or no value, perhaps operated by those without the means or attitude to keep it properly. Abuse and neglect can quickly ruin even the finest machine.

Neither of these factors apply today with the typical vintage car and owner, and that means to me that a well-maintained Packard of the era we speak, operated sensibly will last indefinitely. I like to consider also the operating environment of the time when the machine was new. Two-lane roads of dirt and macadam, speeds typically thirty to fifty, maybe sixty or a little more if you have a big expensive car or you're a kid in a Model A. My Packard is a sort of a time machine, at least in my mind, and I run it the way I presume it had been back then. If I want to go fast, I have other stuff, my El Camino and a couple sports cars. They have brakes, tires, suspension, etc., to allow it. And note: some of my newer cars are modified (by me), just so you know.

Babbitt had a good long run for many years and is still used in industry. One could make the case that a major reason that automotive shell bearings found favor was the efficiencies to be gained by eliminating a timely and tedious and thus expensive process that had to be performed by men with brains. Any nitwit, myself included, can drop in a set of bearings and usually get them right way around. The art of scraping babbitt is a joy to behold, when you can find it. Just for that alone it should be supported.

Is there an engine speed, i.e., a specific RPM, above which the engine will fail, and below which the engine will proceed happily forever? Certainly. I don't know what it is; it could be experimentally derived but at the cost of a few broken engines...

Generally, and this is fall-off-a-log obvious, run an engine at a low enough speed that it is "happy" but not so low that it struggles and can't pull a hill. If you want to go faster, put a different gear in the diff. Trust in Colonel Vincent to have designed, built and tested what was at the time America's finest engine and you won't go too far wrong.

By now, you can no doubt guess my position, if not, I'll state it bluntly. Why on earth carve up a perfectly good antique so it has what YOU consider to be an improvement? Somebody, memory suggests to me that it was an old race driver, maybe Nigel Mansell or James Hunt, said upon viewing an extensively modifed car, and I paraphrase here, "Looks like he started with the wrong car".

[Packard8]

This has been talked heavily in the past. <snip>

I paraphrase here, "Looks like he started with the wrong car".

A very succinct post. And all accomplished without copious "BOLD FACE ITALIC QUOTATION MARKS" !!

[trimacar]

BillP, I agree with you, up to a point. What happens is, there are numerous cars out there not so lovingly cared for as was and is your 1934. Thus, things fail, and must be repaired. Invariably, a crankshaft will then be ground 10, 20, 30 thousandths under. Now, replacing it with babbitt, with all the variables involved (material, skill of installer, etc.), and knowing that babbitt that is too thick may build up heat and tend to fail, one wonders what the alternative is, short of machining a new crankshaft.

I am in favor of keeping things original, as are all my cars, but at some point a decision must be made, what is the best thing to do to keep it touring? I enjoy driving the cars, so to make a relatively minor mechanical change, and help ensure dependability, is not a big deal to me.

Surely a good post you have there, though. I'd still be running all babbitt in my Pierce, if other circumstance had not forced me to take the engine apart (an engine fire, if you must know), and in doing so discovered babbitt failing, and on the verge of failing, in the rods.

By the by, some of the reading I've done shows that "redline" on a Packard V12 is 3200 rpm. I would think a similar number would be right for an 8.

[Guest RenegadeV8]

Bill P writes:

"I have a 34 like Owen's; so far as I can tell, it has never been re-babbitted. It's essentially an original, one-owner car with about 65,000 miles. Admittedly, one swallow does not a summer make, but it is interesting to note that it continues to conduct itself as intended. "

Pretty good longevity. A few questions:

How many times have u shimmed or filed the crank and rod caps???

How many times have u replaced the piston rings????

[Guest BillP]

In the bundles of stuff that came with car is a small box containing what I reckon is a complete set of shims, removed, I guess, at intervals over the years. I've not filed the caps; the journals look pretty good. No re-ringing by me, I don't remember if it shows up in old service records. I'll have a look.

[Rusty_OToole]

Just to make the whole question more confusing has anyone considered replacing babbitt bearings with aluminum?

It happens I know people who have done this. One was an Indian 4. The owner, an expert Indian mechanic, replaced the original roller bearings with sleeves made from aluminum tubing in the early 50s. He rode that bike many thousands of miles before he died in the 90s. So far as I know it still has the aluminum bearings and is still going strong.

The Vincent motorcycle company, when they wanted a stronger bearing for their racing engines, replaced the stock roller bearings with aluminum. It worked fine as long as they had a good oil filter. Aluminum is not as forgiving as babbitt so if a piece of grit got in the bearing it would cause trouble.

Triumph motorcycles in the 50s came with aluminum rods with the rod material forming the bearing surface. Many many car and motorcycle engines have been made of aluminum with the camshaft running directly in the block or head starting with air cooled VWS and on into today's Hondas.

A good machinist may be able to replace the babbitt bearings with aluminum easier than adapting shell bearings or pouring new babbitt.

Edited December 22, 2009 by Rusty_OToole (see edit history)

[Guest BillP]

Good point, Mr. O. Many small engines do that, I think all the lawn mowers I took apart years ago were that way. Type of alloy would be important, of course.

Speaking of roller bearing cranks, as you probably know, Porsche used them in the fifties on their 4 cylinder 4 cam race motors, I think. Made by Hirth, they were fussy and most have been difficult to assemble and clearance properly. Also, I read somewhere that engine revs needed to be consistently above 2500 to provide a flow of oil; otherwise gall, disassemble, spend. They eventually went back to inserts.

Interesting in light of this thread, where we contemplate 2500 as at or near the top of the range.

Your comments also remind me of Burt Munro, who, according to contemporary Hot Rod magazine reports, sand cast his own pistons for his Indian.

[tbirdman]

Some very interesting replys.

Ken, let me ask you; what RPM do you feel is sustainable? do you feel 2450 @ 55 MPH is acceptable? I have never really seen anyone with this family of engine give a definitive redline, or cruise RPM, just lots of speculation.

2450 at 55 seems a very reasonable rpm. When I drive it between 50-55 it doesn't seem to be maxed out or straining, but comfortable at that speed with plently more speed able to be gotten from the engine.

The interesting thing I saw about that table posted (and where I got my original info from by the way) is at 50 the difference between 6.5X19 and 7X19 tires is 100 rpm. The difference between the gear ratios is about 150 rpm. So for my comparison with Owen who is comfortable at 50 but has a a higher gear ratio(4.69 vs 4.41) and smaller tires (17 vs 19), then my 32 at 50 with rpms at least 250 rpm less (not taken into the full account of 2" taller tires), I should be golden.

[tbirdman]

Met a 1930s Packard owner atthe HCCA meeting tonight. It has 90K miles on the original engine and he has put 60K ofthose miles on. Engine has never been rebuilt and he drives it at freeway speeds.

One interesting thing is he claims it has an in-dash radio, and that it came delivered from Packard that way. I had thought the first in-dash radio for Packard was in 33 or 34, and 32 was the first year you you could get a radio though it was steering column mounted tuner.

[Restorer32]

We restored a 1910 Pullman in which the main bearing caps were babbitt but the top half of the bearing was just the aluminum block.

[West Peterson]

One interesting thing is he claims it has an in-dash radio, and that it came delivered from Packard that way. I had thought the first in-dash radio for Packard was in 33 or 34, and 32 was the first year you you could get a radio though it was steering column mounted tuner.

I'd like to see more info on that. I would also like to see a photo of how and where it's installed.

[K8096]

It's probably a Transitone radio, installed either in Detroit or Long Island. They came out in 1929 and were available for all cars except the Ford Model A because of the gas tank in the dash. It consisted of two large dials in the center of the dash, and all the other instruments were relocated to either side. The main radio box was right behind the center of the dash. Under the rear floor boards was a battery that powered the radio. A little later they upgraded this to a small electric motor that converted 6 volts to 120. The radio was basically like one you would have in your house. On closed cars the horn like speaker was mounted above the windshield, on open cars it was on the inside of the firewall. I've heard of a couple 1929 - 1930 Packarsd with this installed, but have never seen a picture. There are about 5 Model M Stutzes in existence with this feature.

[tbirdman]

I'll try to get more info about the radio at next months meeting.