:iagree: I live in an area ripe with racing activity and know many people in that business. Nearly all of them run synthetic no matter what kind of oil they have to "say" they run.

 

Rebuilt or overhauled motors are not built to factory specs and conditions. You can't use synthetic if your engine wasn't prepared for it. GM, Porsche, etc have million dollar machines doing their machine work. The shade tree mechanic doesn't have that available to him. Mobil 1 does not say that it is o.k. to break in a rebuilt engine with synthetic, just that some new cars use it.




[Modified by Chosen Won, 6:37 PM 4/12/2004]

 

its always just been my theory that mechanical parts dont break in...they wear out...therefore I want the best protection from the get go...I think that
is mobil 1...Ive rebult several motors over the years and have used Mobil 1 as the intitial fill...never had a problem...just my .02 cents......
:seeya

 

"Rebuilt or overhauled motors are not built to factory specs and conditions. You can't use synthetic if your engine wasn't prepared for it. GM, Porsche, etc have million dollar machines doing their machine work. The shade tree mechanic doesn't have that available to him. Mobil 1 does not say that it is o.k. to break in a rebuilt engine with synthetic, just that some new cars use it."

Yeah, rebuilt engines are most often times (when done by a special shop, not store bought) built to greater spec/tolerances then the factory could ever dream of doing on a production line.

I'm sure more than half the people here who built their own Hi HP motors spent a great deal more time on the tolerances and specs, then GM did on the build line. If the specs are better on a factory engine then why do you get what is suppose to be 1.5 ratio rockers on a stock car, but end up more like 1.3-1.4?

I hear this "You can't use synthetic if your engine wasn't prepared for it." I want to know since so many people say it. Back this claim up please. Where is it written that this is true? If the above is true then what is it that is done different to make mobile 1 OK from the factory but not a rebuild? What's the magic?

:confused: :confused:


[Modified by 88_vette, 9:45 PM 4/13/2004]

 

Use dino oil and change it in 5's
5 minute run time-Walmart
50 miles-Walmart (needs to get hot to set the ring)
500 miles-walmart for a loose motor/synth for a tight motor (also needs hammering to set the rings)
3000-5000 miles change to synthetic 0W-30

 

General Motors used Mobil 1 as first fill on LT1 LT4 and LS1 engines. This list does not include the L-98. These engines were designed, honed, and bored to use the Mobil 1 oil. They have a different pattern that is optimized for the synthetic. This pattern is not duplicated anywhere except by the manufacturer and the highest end machine shop. Don't believe me? Write GM or Mobil 1. Or read this. Please notice that nowhere does it say that Mobil1 is better than a dino oil for breakin of a rebuilt motor. It just says it is possible, not better or even as good.

I believe that many of you will find the following mails between me and the Mobil Corporation of interest. First comes the final answer of Mobil, then the previous mails.

Cristiano Rossi
thpnma 02869

----- Oprindelig meddelelse -----
Fra: Mobil Oil <mobil@ourdataworks.com>
Til: Cristiano Rossi <rossi@image.dk>
Sendt: 3. november 1999 17:24
Emne: Re: Mobil 1 for breaking in an engine?


Thank you for contacting Mobil.
Today's engines are built with much tighter tolerances and much improved machining compared to the engines of 10 and 20 years ago. The old concept of "engine break-in" involved two primary elements:

Removing any metal flashing (called swarf) or abrasive material
Allowing valves and rings to "seat" properly.

Today's engines do not require these break-in periods. In fact, Mobil 1 has shown excellent control of oil consumption in the industry standard ASTM Sequence III E test, which uses a completely rebuilt engine for each new test run. This includes freshly honed cylinders, new pistons, and
new rings (compression and oil control). The engine is exposed to only the test oil after rebuild. The outstanding oil consumption control of Mobil 1 in this test demonstrates that the old "seating" issue is not of concern in well machined engines. And don't forget that Mobil 1 is used as
initial fill on Corvette and Porsche engines.
However, if the engine rebuilder is using older machining equipment or lower quality components, it can leave you with an engine containing swarf or abrasive material inside the engine. In this situation, you would be best served by using a short drain interval on your initial oil fill.
Mobil 1 will still work in this situation, but it would be less expensive to use a conventional oil for this first, short duration fill.

If you have any additional questions, you may contact us at our E-mail address: lubes@ffx.mobil.com or by phone at 1-800-ASKMOBIL.
>
>
>
> Cristiano Rossi wrote:
>
> > To the Mobil Corporation.
> >
> > On 13. july 1999 I sent you the following e-mail:
> >
> > ---------------------------------
> >
> > Mobil 1 for breaking in an engine?
> >
> > To The Mobil Corporation.
> >
> > I have a question that I would like you to answer. You can often read recommendations like the following in the newsgroups etc.:
> >
> > >""One thing that you should be carefull of is the Mobil 1. It is great oil
> > >and will make an engine run better and last longer. The problem is that it
> > >is not suitable for CAM break-in. It lacks the correct extreem pressure
> > >lubricants for this purpose. I have been advised by Cam makers to break in
> > >about 500 miles with regular oil before mobil 1. Then Ring makers recomend
> > >2000 miles for proper ring seat before using mobil 1.""
> >
> > I normally use Mobil 1, and I have also used it for breaking in a completely rebuilt engine. Is it true that it was a bad idea to break in the engine with synthetic oil?
> >
> > Thank you in advance for your kind reply.
> >
> > ------------------------
> >
> > On 17. july 1999 you sent me the following reply:
> >
> > ------------------------
> >
> > Mr. Rosi,
> >
> > Thank you for contacting Mobil. Please accept our apologies for the
> > delay in replying to your email.
> >
> > You can start using Mobil 1 in new vehicles at any time. In fact, Mobil
> > 1 is the factory fill in Corvette LS1, LT-1 and LT-5 engines. And
> > Mobil and Porsche just announced a new partnership that will also have
> > all Porsche cars manufactured at the Zuffenhausen plant lubricated with
> > Mobil 1. One of the myths that persists about Mobil 1 is that new
> > engines require a break-in period with conventional oil. Current engine
> > manufacturing technology does not require this break-in period. As the
> > decisions by the engineers who design the Corvette and Porsche engines
> > indicate, Mobil 1 can be used in an engine from the day you drive the
> > car off the show room floor.
> >
> > If yoX-Mozilla-Status: 0009questions, you may contact us at our E-mail
> > address: lubes@ffx.mobil.com or by phone at 1-800-ASKMOBIL.
> >
> > ---------------------------
> >
> > On 17. july 1999, I sent you the following questions (sent to the address <lubes@ffx.mobil.com>):
> >
> > ---------------------------
> >
> > To the Mobil Oil Corporation.
> >
> > Thank you for your interesting reply to my question. I understand that with the current engine technology it is not necessary to break in an engine with conventional oil.
> >
> > I have breaken in a completely rebuilt Ford 351 Cleveland engine with Mobil 1. The engine has now been running about 10.000 miles, only on Mobil 1. The Cleveland is an engine from the early seventies, and can probably not meet the standards of what you call "modern engine technology".
> >
> > I have two additional questions:
> >
> > 1) Would it have been wiser to break in this old (but rebuilt) engine with regular Mobil oil, and then change to Mobil 1 after the break-in period?
> >
> > 2) If it is recommended to break in older engines with regular oil, can the possible damage now be corrected by using a regular oil for a certain period?
> >
> > I thank you in advance for your kind reply.
> >
> > --------------------------
> >
> > I have not yet received any answer to my last questions dated the 19. july 1999.
> >
> > I would be glad to receive your kind reply.
> >
> > Thank you in advance.
> >
> > Cristiano Rossi
> > rossi@image.dk

So Mobil 1 uses the same machines that GM or whoever else uses Mobil1 in initial fill to rebuild the motors for their tests. 99.99% of the machine shops a person will use does not have this setup.

Redline Oil and AMSOil do not recommend breaking in a rebuilt engine with synthetic oil, even their own.


AMSOil

Redline and Road & Track

In fact, AERA does not recommend using synthetics for break-in either.

<A HREF="http://www.aera.org/Consumer/breakin.htm" TARGET="_blank">AERA</A>

You guys can do whatever you want with your rebuilt engines. For mine, I will stick with a good dino oil for break-in, and switch to mobil 1 at 3000 miles. A conventional oil will not damage your engine for that 3000 miles, but a synthetic might. It's not even a close call.

There's all the proof I need, where's yours?




[Modified by Chosen Won, 10:37 AM 4/14/2004]

 

IT never mentioned honing being different.

It simply stated what was stated earlier in fact. That the tolerances of todays engines are much better and this allows you to simply avoid this swarf stuff. Which in return means you don't have to drain it asap after first warm up. They also stated that using it as a first filll oil is fine but you would have to drain asap and cost would be higher, but no where did it say that it would keep the rings from seating, or the engine from breaking in.

"However, if the engine rebuilder is using older machining equipment or lower quality components, it can leave you with an engine containing swarf or abrasive material inside the engine. In this situation, you would be best served by using a short drain interval on your initial oil fill.
Mobil 1 will still work in this situation, but it would be less expensive to use a conventional oil for this first, short duration fill."


Doesn't say it can't be used, just cost more because of the short drain interval.

 

First off, realize that this is all in good fun, and I'm not trying to be mean or anything. Just good fun.

The rest of the articles mention the differences in the boring, etc. You are correct, the Mobil 1 does not. Mobil 1 also does not say that it is better for first fill of a rebuilt engine. It's not what they say, it's what they don't say. It simply says that Mobil 1 will still work, but gives no other specifics. Will it work better? Faster? As well? As good as Mobil 1 is at pushing it's products, if any of that where true, you could bet that they would come right out and say it. But they don't because its either not true, or they don't know. I'm willing to bet they do know, it just doesn't favor them.

 

If you are breaking in a brand new engine go "dino" oil, if it's just a cam stick with synthetic

 

good point chosen won. They do not mention anything about it being great for a breaken as they do mention it being great for other things.

 

I don"t call it "BREAKING IN".

To me it's more "FLUSHING OUT".

Swarf, dust, dirt, crap, whatever. It doesn't matter how clean you try to be there's a lot of 'stuff' left inside the engines 'we' build.
Many times we aren't working with new parts or a production environment where everything is pristine,parts have been triple washed, etc..

The rebuilt engine needs to be flushed out. Some particles will be caught by the oil filter. Hopfully the rest of the particles that could cause damage/shortened engine life will be drained out with that first oil change.

Why spend 25 bux to flush out with Mobil 1 when you can do it with 6 bux worth of 'Coastal' or whatever cheap oil you want to start up with?

RE: Ring Seal.........
Most of you..(me included) will prbably use 'moly' faced rings. Molybdenum is an EXTRMELY soft substance. You can scratch it with your fingernail.
If you didn't hone the cylinders for it then in the first 5 minutes of running most of it will be worn away and the rings will be seated.
If you DID hone for moly rings then in the first 10 minutes the rings will be seated.
Doesn't matter WHAT oil you use.

There's really no other breaking in of consequence UNLESS you installed a new cam and flat tappet lifters. In which case it matters MUCH more the RPM you run for those first few minutes than the type of oil you filled with.

And THAT'Sa topic for another thread.

 

Myth busted...

Synthetics are better when the motor is built to higher tolorances...

Uh... yeah that's true for any good build

I may be a new vette owner... but oil... good oil... is still graded...

I put together a number of motors, and had a few delivered to me that showed me the difference between a good build and a superior one.

not all oils are the same, but good oil stands the test of time.

Most synth oils ARE high grade... many dino oils are too.

The difference is the builder... because the oil should get changed before the stuff causes a problem anyway... the point is moot.

Either will work. And work well... synth just stays in at a higher temp.

I've run both... straight, mixed, on-the-rocks. I've popped more than one motor, and I know the value of good prep work. Those of us that run the motor for what we can get out of it will see a benifit with an oil that stays viscose at high temps ( track et's can really put a strain on more than just the motor).

Motor run-in should be done with a good oil.

Mobile is a good oil. I do not use it in all my cars. But in the higher performance motors... like the vette... a little insurance in a sound well prepped motor cannot be understated.

Don't be afraid of using a synth motor oil for run-in of your motor. And if you leak... it wasn't done right in the first place... it ain't just the oil bud.

Just my 2cw