Effect of diesel-rated oil on cam lobes and valve lifters in gas engines

[Motorbike]

I just wanted to add that the reason for reduce valve overlap is obvious to many and thats emmisions . The reason for reduced valve train weight will not be to many here .

The now near common place use of non-symmetrical cam lobes and computer generated models of vs the hand plotted mathematical formulas such as the Fourier Series of yesteryear allow for a much smaller base circle than older designs . Anytime you can increase the valve lift without increasing the duration and resulting valve overlap you'll have problems keeping the lifters/followers/valves controlled without increased spring pressures and racing oil in certain applications .

The next best way to control the valve opening/closing events are to lighten the valve train....... the results and applications from racing programs and technology learned from are used on the street in many grocery getters today

 

[Jelly]

Motorbike,

Those are some nice replys there and I thank you for taking the time to write them out.

When I said "friction modified" oils, I was simply referring to PCEO's...

Second, please don't even try to talk to me about GF-3/GF-4 oils and engine cleanliness...there is simply no honest way you can tell me a GF-spec. oil is gonna keep an engine as clean as an HDEO.

Look, I'm not gonna write out a long reply to back up what I'm saying here, but to me, it's simply as this.

If you're looking for maximum anti-wear protection and engine cleanliness, then pick a HDEO.

If you're looking for good protection (and protection levels vary widely in PCEO's, with top-end synthetics offering great protection in gas engines) mixed in with the ability to get a little better fuel economy, then pick a PCEO.

Sure, modern production gas engines may not exert the pressures that require a HDEO, but I'll take the added protection...

 

[Jelly]

quote:

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Originally posted by heyjay:
As far as engine cleanliness and long life, a regular non-synthetic HDEO 15W-40 is FAR superior to a regular non-synthetic PCEO. There is a slight to nil effect on fuel economy.

---

I couldn't agree more...

 

[Doug Hillary]

Hi,
JERRY and JELLY - thats the conclusion I arrived at from EXTENSIVE testing in New Zealand in the 1950's and in Copenhagen as an employee with Caltex-Chevron in the 1960's.

HDEO's worked wonders on troublesome petrol engines then and that's why I've used them ever since. Its just one reason why Porsche have always required the secondary diesel rating for its oils

Regards

 

[TooSlick]

I'd say a 15w-40 engine oil will generally show lower wear rates than a 5w-30 or 10w-30, gas engine oil if the ambient temps are above freezing ....

It's a thicker oil with signicantly more ZDDP, so it will usually provide more valvetrain protection. However, the 5w-30 oil will provide better engine performance, cold starting and fuel efficiency. So it's a mixed bag ....

My testing of the Series 3000, 5w-30 showed the same wear rates as with the Amsoil 0w-30 and 5w-30, at least in my personal vehicles. The S3000 did hold up better over long drains than even the S2000, 0w-30. I have no idea how Delvac 1 will hold up compared to Mobil 1, although the TBN is a bit higher to start ....

Tooslick

[ February 23, 2004, 09:34 AM: Message edited by: rugerman1 ]

 

[heyjay]

quote:

---

Originally posted by Doug Hillary:
Jerry, one fleet I work with - a long term Cummins purchaser - had a very bad run with the Signature 500/600hp engines. He sold the lot after about 18 months use. He has had a good run with about 50 ISX motors but has just commenced a purchase programme based on Detroits. He has also tried the Cursor/Cummins range ( made by IVECO ) and has had an excellent run so far

Indirectly, independent tests here on the troublesome GM V8 have shown that M1 5w-50 is a great brew that they tolerate very well. Oil use has been reduced dramatically with no adverse effects. M1 R appears to do the trick too!

I am in Townsville, Far North Queensland today - 400kms north of where I live at Airlie Beach. The temperatures here were 27C overnight and at 2pm today it was 41C! The Z3 had a good work out for an hour or two above 100mph at the same time

I'm pleased to hear spring is springing for you!!!

Moribundman - your oil choice is an excellent one

Regards

---

Hi Doug:

The Cummins Signature series was a disaster for them, wasn't it? You would think with Fleet Testing they would have uncovered that nasty surprise.

Once you have a bad experience, you usually NEVER go back to that brand. You also tend to badmouth it every chance you get. Again, you'd think the big-wigs would understand that.

Even if you spend $1 million on Fleet Testing, that is NOTHING compared to lost sales, bad customer relations, poor brand image, etc etc.

I spoke too soon about Spring and must have jinxed it: heavy snow as I'm typing this. I am truly jealous of your wonderful Oz weather!

Doug, imagine the motor situation in North America where you have MILLIONS of LS1 car and LS1-derived truck Vortec motors, all with a certain degree of problems.

Especially the first year build, the 1999 Chevrolet Silverado pickup trucks and 1999 GMC Sierra pickup trucks. A lot of them are now in Used lots and I shudder to think of the guillable buyer who isn't aware of this problem.

I live about an hour away from a Cold Weather Test area, and many car makers test their cars in extreme cold. They also plough the snow off the lake and use the slippery ice to test the traction control and ABS.

I think GM did uncover an oiling problem in extreme cold with their LS1 and truck Vortec motors, as they recommended in the manual using a synthetic 0W-30 in temps colder than -20 F / -30 C.

A lot of Vortec owners who used a heavier viscosity (10W-40/20W-50 or synthetic 15W-50) in hot temps were able to substantially reduce or even eliminate their noise and oil consumption problems.

As long as the temperature is above 0 F / -18 C, Mobil 1 15W-50 is quite safe. I used Mobil 1 15W-50 year round in Utah in my 1990 Toyota 4Runner with 3.0 V6, and in cold starts at -18 C, no noise and quick oil pressure.

Jerry

 

[heyjay]

quote:

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Originally posted by Motorbike:
Quote:

I don't care much for friction-modified oils unless I'm trying to acheive maximum fuel efficiency levels, but I'd much rather have MAXIMUM WEAR PROTECTION than maximum fuel economy...but that's a whole other discussion.

Friction modified oils are nothing new . The only thing that's changed in the last 10 years or so is the type used .

API SL ISLAC GF-3 placed a premium on oxidative thickening . The traditional oxidation inhibitors were ineffective so three way combos of Moly , Nitrogen containing complexes " Borated Dispersents " and Sulfurized Ester Olefin " controls oxidative thickening " were developed and used in the low cost oils and now expands to include use in better oils. " witness Mobil SS and other formulas ". ISLAC GF-4 will also place a premium on piston ring belt cleanliness using sequence III-G in purpose , demands and requirements .

All I'm saying is these oils friction modified or not does not depict how long a cam/lifters will last in modern gas motors "modern is a keyword here" . A combo of quick flow to them in these modern OHC engines along with ample amounts of anti-wear such as zinc would be better in reasonable drains than an Army

of zinc that took forever to get to the battlefield " flow/pumping ". I'm not talking 20wts either though just so to be clear .

None of the current gasoline motors needs huge amounts of Zinc these days due to ever decreasing open and closed valve spring pressures and ability to use less of due to lighter valve train components and the newer variable valve timing to aid in reduced valve overlap w/o cost of top-end power .


Long drain intervals and increased ZDDP...different deal . Zinc is also a good anti-oxident

---

Motorbike:

I find it truly fascinating that GF-4 is finally going to address the issue of Ring Land Grove Fill.

HDEO first had to address this issue in the early 1980's. With the Ring Land moved much closer to the Crown Land, improper additives and poorly refined oils contributed to substantial Top Grove Fill and stuck/broken rings.

The current Top Grove Fill is set around 15%

I imagine GF-4 will require different FM packages. It was proven in HD diesel motors 20 years ago that regular PCEO FM additives contribute to substantial Top Grove Fill.

That is why every HD diesel engine maker forbids the use of "fuel saving" FM packages in HDEO. A few HDEO like Mobil Delvac 1 add special "fuel saving" FM additives that don't contribute to Grove Fill, but those additives are quite expensive.

For the average driver, a "savings" of 1-3% over the "reference" oil is statistically insignificant. If you truly want to save fuel, do the following:

1. Keep tires properly inflated, use highway all-season tires instead of aggressive tires

2. Air filter must be kept clean

3. Spark plugs must be clean

4. Buy a smaller car

The 1.5 l Toyota Echo Hatchback is very fuel efficient. I'm sure a 1.2-1.3 l 3 cylinder would be even more so. I have no problem trading performance for economy and don't need tire-smoking performance.

As far as engine cleanliness and long life, a regular non-synthetic HDEO 15W-40 is FAR superior to a regular non-synthetic PCEO. There is a slight to nil effect on fuel economy.

Most folks who run HDEO in passenger cars have truly benefited from all the advantages.

Jerry

 

[therion]

THANKS for the information

I found it very beneficial.

 

[TallPaul]

quote:

---

Originally posted by Jelly:
If you're looking for good protection (and protection levels vary widely in PCEO's, with top-end synthetics offering great protection in gas engines) mixed in with the ability to get a little better fuel economy, then pick a PCEO.

---

Excluding synthetics, do you think that in general the non-starburst/energy conserving oils (all high mileage oils and any 10w40 or higher grade oil) as a group are a good deal better than the friction-modified starburst/energy conserving oils? Seems to me we really have three classes of oils: Friction Modified PCEO, Regular PCEO, and HDEO. Obviously, the first two groups are not that far apart relative to the third, but within the PCEOs the difference may be significant.

 

[TheNauseator]

quote:

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Originally posted by Jelly:
Jerry,

I just want to say thank you for sharing your knowledge regarding HDEO's with us and taking the time to type out these fact-filled, well-written, detailed replies!

---

BITOG

 

[AV8R]

Regarding the "flaky" wear on the cam lobes, this signature is characteristic of fatigue wear. In this case, it is likely that the hertzian contact pressures are exceeding the fatigue limits for the material. This can be a materials problem, or a lubrication problem, with higher viscosity oil giving lower hertzian stress.

 

[Doug Hillary]

Hi,
AV8R - the flaking aspect of cam lobe wear on certain makes/models of heavy diesel engines has excercised the minds of the best Engineers for some years. It touches such things as the method of hardening the cam lobe amongst many others

The aspect of quality control at manufacture point is one aspect
The contact patch of the roller to lobe is another. Because of the broad rolling contact required a slight alignment mismatch places enormous stress on a very narrow contact patch
The move to twin overhead cams - one operating the valves and the other the injection mechanism has assisted but still it happens - spasmodically!
Cam wear on certain brands has been a continuing saga since about 1978
The modern heavy diesel is a very complex above the piston top due to the twin requirements of absolute emission control and longevity
Synthetic HDEO's have been a marvellous leap forward to minimising some of these problems

Some NA engine makers have solved the problem - others have not. It is NOT a problem in Euro heavy diesel engines and to my knowledge never has been!

Regards

 

[sprintman]

Doug I beleive it was either 46.8C or 48.6C at Ivanhoe recently. Did you hear that too?

 

[Doug Hillary]

Hi,
Sprintman - yes it was 46.8C I think
I was in Townsville on Sunday - it was 36C at 7.30pm!

Good in the Z3 with the roof down though - like a sauna without water

Humidity here has been between 86 and 96 for about 10 weeks I think

Regards

 

[Drew99GT]

Do HDEOs in reality contribute to more combustion chamber deposits/ring land deposits in gas engines, especially heavy oil burners? I've seen that posted here, because of the higher ash based additive package I guess.

 

[heyjay]

quote:

---

Originally posted by Drew99GT:
Do HDEOs in reality contribute to more combustion chamber deposits/ring land deposits in gas engines, especially heavy oil burners? I've seen that posted here, because of the higher ash based additive package I guess.

---

No.

For almost 20 years, HDEO's have been specially formulated to MINIMISE those sort of deposits.

When the EPA-mandated emissions controls required the piston Ring Land moved much closer to the Crown Land, oils with poor additive packages contributed to heavy and quick Grove Fill.

Just the way HD diesel motors are designed, they use more oil than a passenger car motor (I'm excluding the LS1 oil guzzler).

In most cases, if you add 1 litre every 4,000km (1 quart every 2,400 miles) you have excellent oil consumption control. Some HD diesel motors drink 1 litre every 2,000km or more.

So the HDEO is designed to minimise deposit formation, especially in the piston Crown Land and in the piston Ring Land. Regular PCEO cannot minimise deposit formation under those conditions, which is why HD engine makers forbid the use of PCEO or certain FM additives in their motors.

Jerry

 

[Drew99GT]

Thanks Jerry. I'm givin Delo 400 a try for my next oil change. For under 7 bucks a gallon, it sounds like ther absolute perfect summer oil to run.