Road & Track - Breaking in Engine on Synthetic

[buster]

Being this has come up lately, myself included, I thought I would post these two articles.

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Using synthetic-oil in engine break-ins
By Road & Track, Technical Correspondence Column, July 2000 issue


Many readers have questioned us on engine break-in procedures when using synthetic oil. Conventional wisdom has it that a new or freshly rebuilt engine should be broken in using mineral oil, then, once enough mileage has accumulated to ensure rings and cylinder walls have lapped themselves into harmony, synthetic oil can be used.

Readers have correctly pointed out that several major brands come from the factory with synthetic oil, among these being Corvette, Mercedes-Benz and Viper. How can these engines break-in if run on synthetic oil from day one, they ask?

To find out, we spoke with Mobil and Redline Oil companies for their take on the synthetic break-in question. Mobil's response was that engines break-in just fine on synthetics, and that any wear point in the engine significant enough to be an interference, and thus susceptible to rapid wear, would be a wear point no matter what lubricant is used.

Redline, on the other hand, has found it best to recommend a mineral oil break-in. Occasionally an engine will glaze its cylinder walls when initially run on Redline, they say, so by using a mineral oil for 2000 miles, verifying there is no oil consumption and then switching to the synthetic, glazing is eliminated.

Cylinder-wall glazing is not a deposit left on the cylinder wall, but rather a displacement of cylinder-wall metal. This happens when the high spots of the cylinder wall crosshatch are not cut or worn off by the piston rings, but rather rolled over into the valleys or grooves of the crosshatch. This leaves a surface that oil adheres to poorly, against which the rings cannot seal well. Compression is lost and oil consumed, and the only cure is to tear down the engine to physically restore the cylinder-wall finish by honing.

Why is glazing not a problem for the major manufacturer? Because they have complete, accurate control over their cylinder-wall finish and ring type. Redline deals with a huge variety of engines and manufacturers, both OEM and from the aftermarket. Cylinder-wall finish and ring type thus vary greatly, and glazing can therefore occur, albeit rarely.

While we were at it, we queried about synthetic oil-change intervals. Mobil says to use the maximum change interval specified by the engine manufacturer, regardless of oil type. Redline said that once past an OEM warranty, anywhere from 10,000 to 18,000 miles, or one year, whichever comes first, is appropriate depending on conditions (dust, short trips). They also recommend changing just the oil filter at 6000 to 7000 miles as a precaution against overloading the filter. Redline further noted a caution when using synthetics with leaded fuels, as synthetics do not hold lead in suspension as well as mineral oil. Aviation is one area where leaded fuel is still widespread, and avgas is often used by off-road and racing enthusiasts, so a relatively short oil change interval may thus be indicated.


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Synthetic Break-in
By Tom Wilson
Road & Track, Technical Correspondence Column, November 2001 issue


Exxon/Mobil's official policy is that their synthetic oil may be used at any mileage, including factory fill, unless otherwise stated by the vehicle manufacturer. Mobil pointed out, as you did, that all Corvettes, Vipers, Porsches and Aston Martins are factory filled with Mobil 1 synthetic. We can only conclude that improvements in cylinder-wall finish and ring design or materials makes this possible.

It is also likely that vehicle manufacturers not using synthetics as the factory fill are also not optimizing their cylinder and ring packages for the slippery sythetics, in which case approximately 1000 miles on mineral oil should prove ample break-in time. In fact, in modern engines a very high percentage of ring break-in takes place very quickly, probably in the first 10 to 20 minutes of engine running. Certainly, some final lapping of the rings and cylinders takes place over several hundred miles after initial break-in.

Just to add some confusion, Porsche dynos all of its engines before installing them in the chassis. We were unable to determine what oil is used for the dyno session, but would presume it's Mobil 1


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[oilcan]

Interesting, I'm very sure this question will be discused for years. My wife just bought an 04 Chevy Trailblazer and our Dealer suggested we go 10,000 mile then switch, and this seems to go with Exxon-Mobil which is what they sell. Yet the Trailblazer has an all alum. engine as I believe the Corvettes are and they run Mobil 1 out of the box. Go figure.

 

[Steve S]

I am not a beliver that pao is much different than petro oil as to make a difference in break in. I wonder about Redline and break in, some of the new Honda uoa's have a high moly with the factory oil. I am one that likes to do a low mile oil change on a fresh engine and driveline.

 

[farfel]

quote:

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Originally posted by buster:
Redline, on the other hand, has found it best to recommend a mineral oil break-in. Occasionally an engine will glaze its cylinder walls when initially run on Redline, they say, so by using a mineral oil for 2000 miles

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Okay then. Run the original factory fill for severe service (3000), and then switch to synthetic.

 

[Bob Woods]

Yet the Trailblazer has an all alum. engine as I believe the Corvettes are and they run Mobil 1.

I read somewhere that because of the design of the Vette the oil temp runs higher, so GM puts in an oil that can withstand higher operating temps. The vette needs an oil cooler but there isn't room for one.

 

[GMBoy]

Actually the Corvette lost its oil cooler in 1992 with the LT-1 engine. It was all about cost savings. Delete the cooler while specifying synthetic oil to make up for the lack of a cooler. This proves how much better synlubes are. My corvette never runs much more than 215 or so on hot days for the oil temp.

 

[XS650]

quote:

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Originally posted by Bob Woods:
The vette needs an oil cooler but there isn't room for one.

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Installing an oil cooler on a Vette is easy. It's done all the time.

 

[Patman]

quote:

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Originally posted by GMBoy:
Actually the Corvette lost its oil cooler in 1992 with the LT-1 engine. It was all about cost savings. Delete the cooler while specifying synthetic oil to make up for the lack of a cooler. This proves how much better synlubes are. My corvette never runs much more than 215 or so on hot days for the oil temp.

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Now that I've had my 98 Corvette's cooling fans reprogrammed, my coolant temp never goes above 194, therefore it helps keep my oil temps lower too. Most of the time it never goes above 207F, even in the summer.

 

[GMBoy]

I actually reprogrammed my 03's fans too at one time but than decided to put it back to stock because I don't want all that extra wear on the fans...plus with synlubes it can take the heat. 200+degrees is what GM wants to meet engine efficiency and emmissions, etc. I checked with some GM engineer buddys and the concur that the ideal temp is around 205 give or take. Now the older ones are different - I like my 67 to run under 180.

 

[GMBoy]

Forgot to mention that in my first post I was referring to my OIL TEMP not coolant temp. Big difference, since 215 is not at all hot for oil temps on a hot day.

 

[buster]

I'm not a chemist, but I think he is wrong. Found this on another site.

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I am a chemist with extensive experience in synthetic lubricants. I would
strongly recommend waiting to close to 10,000 miles prior to putting in
synthetic to allow good seating of rings, bore and bearings. Give it 2-3
changes of mineral oil in this time frame, THEN install the synthetic. Don't
believe what Mobil 1 says about break in periods not being necessary; you want to
PROMOTE wear to smooth out microscopic peaks and valleys which are still
present even after machining with the most precise tooling in the world. You
have to think in terms of what is happening on a molecular level! 1,000, 3,000,
5,000 miles isn't really sufficient to wear down these microscopic peaks/ridges.

On your question on of Mobil 1 vs. Redline, without a doubt Redline provides
superior temperature range performance, sludge removal, load bearing capacity, and
antiwear properties because it uses a polyol ester basestock versus a poly-alpha
oliphin (PAO) basestock. Mobil 1 is based on a long chain molecule, Redline is
closer to a microscopic "ball". The ability of the "ball" to roll inside bearing
surfaces vs the ability of the non-branched chains to slip by each other is what
gives the Redline basestock its superior performance, especially since the
additive packages are basically the same.

On the practical side, Redline costs almost 2x more, at least for me (perhaps
others on the list can get cost estimates for Redline from around the country; I
haven't found a good price in NJ). I personally run Mobil 1 in my car. I
could run longer drain intervals now that I am out of warrantee, but I am
obsessive about my car and go with the shorter drain interval.

Hope this helps!

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[crossbow]

quote:

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you want to
PROMOTE wear to smooth out microscopic peaks and valleys which are still
present even after machining with the most precise tooling in the world. You
have to think in terms of what is happening on a molecular level! 1,000, 3,000,
5,000 miles isn't really sufficient to wear down these microscopic peaks/ridges.

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I do agree somewhat with his argument...but after the inital wearing has occured, or "break-in" as many of us call it. Does the secondary breakin really matter if its done on dino or synthetic?

I mean technical synthetic lubes still allow for wear (otherwise there wouldn't be a single debate of dino vs synthetic)...just techincally "less wear" [argued greatly] as per these various experts discussion.

Wouldn't then the point be not that wear wasn't occuring to allow for proper secondary breakin, but it was just occuring slowly? I mean if you switch to syn too early...you'll just extend the amount of time it takes the engine to reach its "ultra super broken in stage". Wouldn't this technically be better anyway since wear is occuring much more gradually?

I honestly don't think it matters myself, I switched to mobil1 on my 2003 Mazda 6s ATX, and I had the higher stock dyno YET out of all the other ATX's.

Some poor fellas threw on exhausts, intakes, and all sorts of goodies, and still dyno'd less them my car did stock.

I just varied the rpm's breakin her in (through the entire rev range), changed the oil at 500 miles (stock factory oil), then changed to syn at 1k.

Of course on the new car I followed the ultra paranoid system of changing at 100, 600, 1600, then syn at 3600. Why? Cause its fun dang nab it!

 

[MGBV8]

May make a difference using an ester based oil to PAO M1

 

[hone eagle]

just a heads up from someone who has discussed this with a machine tool builder(gehring hone)when they intsalled our hone in the late 80's the final step of the new process was something they called plateau hone,this we were told removed several thousnd miles worth of folded metal from the valleys.at the same time the piston pounders noticed the ring tension dropped to a small fraction of what it once was.since then Gehring (and I suspect Nagel )have up dated the honing process with diamond brushing further cleaning the peaks and valleys. these machine tool builders are the only supplers to all the German engine builders from our stuff to ship and stationary diesels. so its possible we are diecussing somting that is no longer as important as it once was. Hone eagle

 

[buster]

Thanks hone eagle for sharing that. Your info. is basically what Mobil has stated. Too many people have changed over early and never had problems. It's a thing of the past. You'll find most people aren't quite up to date with oil and many myths still prevail as we see here on a day to day basis.

 

[hone eagle]

there is a video here somewhere of a million mile engine , and the cross hatch looks identical to brand new never run bores, amazing to me.If they look that way (like new) not much comes off in the course of its life.P.S I watch about 5000 a day go by.

 

[Matt_S]

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Originally posted by buster:
Too many people have changed over early and never had problems. It's a thing of the past.

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FWIW, I'm one of those. I switched to M1 at 1k miles on my Monte Carlo and see very little consumption. This is good information here, though. Nice to know.