Design changes or mileage considerations?

[Truck&Cycle]

It seems there is a trend to go to the lighter weight oils. 0W-20 and 5W-20 etc.

Some manufactures began recomending their use in engines that formerly called for 5w30 and maybe even 10W-30 weight oils.

I can only suspect the lighter oils have been wear tested with the lesser weight oils and the results were acceptable to the manufactures, especially in the MPG category.

Anyone think there has been internal design changes that support the use of lower weight oils or are recomendations based on the the probable slight increase in gas mileage, that the government is demanding vs. acceptable (but maybe not as good) wear patterns under less than ideal conditions as in heavy duty use and extended changes.

 

[Buford T. Justice]

The only design change that even comes to my mind is the 5.7L Hemi motor which is reported to require 5W-20 for its cylinder killer when at constant speed. I can't remember what it is called. It might be B-S.

Other than that, I cannot think of any design changes. My 4.6L 1998 Mustang GT originally was spec'd for 5w30 but has been 'updated' to use 5W-20. I refuse to use it. 5w30 has worked just fine plus I have the hot protection of a 30 weight oil with the cold fluidity of a 5 weight oil. I am considering going to 0W-30 possibly.

Manufacturers care only about themselves. They put 5W-20 in everything to offset CAFE penalties especially with the pensions and other benefits they have to supply for retired workers.

 

[b_rubenstein]

The real changes are the oils. Engines that have been back spec'd for 5w-20 always would have worked fine with 5w-20 weight oil, but not an API SJ 5w-20. The engines calling for 5w-20 require the SL/SM spec, or better, oil.

 

[1999nick]

quote:

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Originally posted by b_rubenstein:
The real changes are the oils. Engines that have been back spec'd for 5w-20 always would have worked fine with 5w-20 weight oil, but not an API SJ 5w-20. The engines calling for 5w-20 require the SL/SM spec, or better, oil.

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This is all absolutely true, IMHOP. Back in the 1950's I had a 1954 Ford, bought new in '54, that I drove to 140,000 miles by 1959, all on the 20W oils of the era. In those days, 20W was the usual oil, until an engine started to burn oil; then a change to 30W was the usual cure. My 140,000 mile engine never required the move to 30W. The mechanical valve lifters never required adjustment, either.

The 5W20 oils of today, that meet the Ford spec, are required to pass a sequence test twice as long as required for regular dino. Most, if not all, of them are synthetic blends, whether they are advertised as such or not. I'll bet that they are at least as good as the straight 20 weights of the 40's and 50's.

 

[1999nick]

As I stated in my post above, my 1954 Ford, a V-8, it lasted me until 140,000 miles, and did not show much sign of wear when I sold it in 1959. It did not smoke or burn oil, and the mechanical valve lifters had required no adjustment, a sure sign of little wear.

I knew many cars in the 50's that were good for well over 100,000 miles. I was in a buddy's Olds 98, a '51 model, and we were doing 100 mph when it clicked over 100,000 miles. Almost every car maker had a new V-8 that was as long lasting as the V-8's of today.

 

[Curious Kid]

Whenever there was mention of using too thin an oil for an application, it seemed to come about with indications of elevated main/big-end bearing wear in UOA's. I don't recall much in the way of cam wear. Timing chain wear might be another indicator.

I'm curious, just what were some of the clearences on the said bearings in theses 50's engines?

Mind you I'm no expert.

 

[Jimbo]

20W-20 used to be the standard spec for most 1950's US cars, true. How long did they actually last before overhaul or the junkyard? I remember average engines going 60-80,000 miles and needing some kind of major internal repair. Today, If you have to pull the heads or oil pan at less than 150,000 is highly unusual.

When early emissions controls started to raise engine temperatures in the 1970's seems to be when oil viscosity specs started to get thicker, 10W-30 and 10W-40 typically. Our 1987 Dodge with the 5.2 gas engine specifies 15w40 or straight 30 for summer.

Today, far superior base oil chemistry is allowing 5w30 and even 5W-20 to withstand extended drain intervals without shearing or oxidation. The major difference in engines is roller lifters, allowing for low HTHS oils without excessive cam and lifter wear. I would not substitute 5W-20 in every old engine, only those substantially identical to the current ones, such as the 4.6 Ford V-8.

 

[LarryL]

It was not the spec'd clearances in those engines 50 years ago, it was the lack of abiltiy to hold those clearances in mass production as well as they do today. Some were too tight, others loose. Today, they hit them right on the button. Today if you have an engine spec'd for 5w-20 you have a better chance of getting an engine that works just like the designers and manufacturers designed it and built it. The statement that V8's of the 50's last as long as today's V8's might require a second look. Take the Toyota/Lexus V8. Those engines go untouched mechanically for 200-300k miles and owners that keep their vehicles expect them to do just that. You go past 100k before the first spark plug replacement. Try that with a Rocket 88, it won't work. Oil is only part of all of this, and a big reason that 5w-20 works is because of the build quality of these new engines, not different clearances.

 

[427Z06]

1953 Olds 303 Rocket
Main bearings: #1,2,3,4 .0005-.003" #5 .002-0.0035"
Connecting rod bearings:.0009-.0029"
Ref: http://www.442.com/oldsfaq/ofe303.htm#E303 303CIDEngineDetail

2002 Honda V6
Main bearings: .0008-.0017"
Connecting rod bearings: .0008-.0017"
Ref: My shop manuals

And one must also consider surface finishes, rollerized valvetrains, piston clearances/finishes, etc.

[ July 08, 2006, 03:03 PM: Message edited by: 427Z06 ]

 

[Steve S]

Lets not mix up quality and newer technology. When comparing 50's cars and 2006 models . The quality of the 50's cars is so much better than the 2006 cars there is no comparisons. The U.S. manufactures started a decline in quality in the 70's that they'r still working to improve. For example the sheet metal is so thin that with out paint you coulds see through the metal or how about G.M.s light weight engine castings? or Fords popping sparkplugs? etc.

 

[dwendt44]

The real difference is surface finish.
Way back when, the finish was rougher, and soon after running, those tolorances would increase a bit.
Today, the finishes are good enough that they won't increase much with running; they stay 'tighter' longer.
I run production grinders at work and the are a lot fussier about the surface finish than they were even a few years ago.
Part of the reason you don't have to do a prolonged 'break-in' on engines anymore.

 

[1999nick]

quote:

---

Originally posted by 427Z06:
1953 Olds 303 Rocket
Main bearings: #1,2,3,4 .0005-.003" #5 .002-0.0035"
Connecting rod bearings:.0009-.0029"
Ref: http://www.442.com/oldsfaq/ofe303.htm#E303 303CIDEngineDetail

2002 Honda V6
Main bearings: .0008-.0017"
Connecting rod bearings: .0008-.0017"
Ref: My shop manuals

And one must also consider surface finishes, rollerized valvetrains, piston clearances/finishes, etc.

---

Clearances and tolerances look pretty close to me, especially given the much larger size of the components in the Olds 303, which later became a 324 and then a 371. Thanks for looking up that info, 427Z06. I wonder how the clearances on that little 3 liter Honda compare to those in a Chevy 427Z06?

 

[427Z06]

quote:

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Originally posted by 1999nick:

quote:

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Originally posted by 427Z06:
1953 Olds 303 Rocket
Main bearings: #1,2,3,4 .0005-.003" #5 .002-0.0035"
Connecting rod bearings:.0009-.0029"
Ref: http://www.442.com/oldsfaq/ofe303.htm#E303 303CIDEngineDetail

2002 Honda V6
Main bearings: .0008-.0017"
Connecting rod bearings: .0008-.0017"
Ref: My shop manuals

And one must also consider surface finishes, rollerized valvetrains, piston clearances/finishes, etc.

---

Clearances and tolerances look pretty close to me, especially given the much larger size of the components in the Olds 303, which later became a 324 and then a 371. Thanks for looking up that info, 427Z06. I wonder how the clearances on that little 3 liter Honda compare to those in a Chevy 427Z06?

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Huh? Do you build many engines?

And as far as the lil' Honda V6, the mains are 2.83" and the rods are 2.09". Quite comparable to the "big" Olds.

Typical Chevy LSx specs are:
Main bearings .0008-.0021"
Connecting rod .0009-.0025"

In summary, tolerances HAVE BEEN substantially reduced over the years.

 

[Lazy JW]

They truly do not build cars the way they used to... and that's a GOOD thing! Back in the good ol' days we wouldn't have had time to surf the internet, we were always FIXING our cars. It used to be notable when a car went 100k, now we think we got ripped off if we don't get 200k. That nonsense about cars lasting just as long in the 1950's is just that; nonsense.
Joe

 

[1999nick]

A Rocket 88 might very well have gone 100,000 miles on a set of spark plugs if it had been able to use unleaded gasoline. Electronic ignition and unleaded fuel cut routine engine maintenance way down. How much does it cost Lexus V-8 owners to routinely replace timing belts in 300,000 miles?

You are right about clearances; what really matters is tolerances, ie, the allowable variation in clearances. I haven't studied tolerances on engines in a long time. Can someone verify that tolerances are tighter now than they were 50 years ago?

 

[LarryL]

I remember the routine, every 2k miles check the points, timing, cap an rotor, and be prepared to change and/or adjust them all. Plugs went a bit longer but nothing like 30k miles. I remember that I could never get it straight about the capacitor. Pits on the ground side of the points meant too little capacitance and pits on the positive side meant too much, or was it the other way around. Setting the points with a dwell meter was high tech, setting them with a feeler gauge was the old way. Cars today are so much better. Even mechanics are different. Today they have computer readouts and change parts. Back then they ground things and fixed things and did valve jobs and brazed things and repacked bearings and got greasy. If I had to commute with a brand new 1950 car, I'd go crazy. My car, today better be good, and a good thing too, because I can't fix it if it quits.

 

[Gary Allan]

In 1950 you probably would not commute long distances to a job. It would be within 10 miles of your home. If you worked in the city and lived in the burbs ..you would probably take the train.

 

[427Z06]

quote:

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Originally posted by Lazy JW:
It used to be notable when a car went 100k, now we think we got ripped off if we don't get 200k. That nonsense about cars lasting just as long in the 1950's is just that; nonsense.

---

I beg to differ. Cars required more attention back then, but if you were meticulous about maintenance, 100K was a piece of cake for a good engine. 3K oil and filter changes and 12K plugs, points, air and gas filters, coolant changes, and 30K tranny oil changes was all that was usually needed unless something specific broke. However, up north, the body usually was rusted out by 100K. Tires, brakes, shocks and pre-cat exhaust systems needed replacement more often, but they were easier and less expensive to replace. I guess it all depends on your perspective on which is/was better.

 

[Titan]

AH, yes....the good old days. Back when "cutting edge medicine" meant you might get a shot of penicillin. Sure, it was a lot cheaper back then...but, a lot more people died of what is today considered to be no big deal.

My first non-motorcycle vehicle was a 54 Ford F-100. No way was that flat-head V-8 anywhere as good as today's engines.

I don't want to go back to the good old days....

 

[XS650]

quote:

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Originally posted by Titan:
AH, yes....the good old days. Back when "cutting edge medicine" meant you might get a shot of penicillin. Sure, it was a lot cheaper back then...but, a lot more people died of what is today considered to be no big deal.

My first non-motorcycle vehicle was a 54 Ford F-100. No way was that flat-head V-8 anywhere as good as today's engines.

I don't want to go back to the good old days....

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That was so long ago you've forgotten what type of engine it had, or the year.

The was the first year of the Y-block OHV V-8 in Fords. Unless is as the OHV I-6 thta was in it's 3rd year of production.