rebuilt engine break-in ques...

[cashflyer]

This debate seems to come up ever once in a while, and it is going on with a club I belong to. Since most of them are driving rice, and I'm weilding mean schnitzengruben, I thought I should get some opinions from Pelicans.

On a rebuilt engine...

What do you do for break-in?
1) Drive it like you stole it?
2) Baby it for X miles? (how many?)
3) Alternate fast days and slow days?
4) other? (explain)

What oil regimen do you use during break-in?
1) Mineral, then synthetic after X miles?
2) Synthetic from day one?
3) Whale oil?
4) other? (explain)

How often do you change the oil during break-in?
1) Daily?
2) Every X miles ? (how many?)
3) When it runs out?
4) other? (explain)


Thanks

[RoninLB]

http://www.mototuneusa.com/break_in_secrets.htm

[cashflyer]

That's a good link, and I agree mostly with his advice. On drag and streetrod engines we have built, we install them, test them on the dyno, and then drive the piss out of them. Never had a smoker or a failure.

But my big question is about the oil. Most people still hold to the theory that "synthetic is too slippery for proper break-in". However,

Using synthetic-oil in engine break-ins
By Road & Track

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 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.

So... Is the synthetic fear just the ghost of old school thinking?

[ChrisBennet]

I use 30W non-detergent when I can get it or 10W-30 if I can't. Being a frugal guy, it would pain me to toss 11qts of Mobile one after just a few (50) miles.
Now if I had a setup so I could break the motor in on a dyno or something I might might consider delivering the motor with synthetic.
-Chris

[GIBSON]

I've always done what Chris said with good results but I do believe in driving the new engine hard with lots a varying revs but don't baby the engine, it will never seat the rings.
BTW, have you noticed the new Castrol synthetic oil commercials where the guy says it's impossible for synthetic oils to hurt old seals and that their oil will not cause leaks around old seals??
Very much aimed at all of us who feel that synthetics and old seals don't match. Interesting.

[RoninLB]

Originally posted by ChrisBennet


I use 30W non-detergent

ditto

[cashflyer]

Originally posted by ChrisBennet ... it would pain me to toss 11qts of Mobile one after just a few (50) miles.

I had not considered this, but I fully agree due to the economics. My debate on the other site is with ricers. They are probably just standard 5qt cars, but now that I am taking into account the $$ aspect I think it wise to do all break-ins with dino. Good point there, Chris!!

Originally posted by GIBSON ... the new Castrol synthetic oil commercials where the guy says it's impossible for synthetic oils to hurt old seals and that their oil will not cause leaks around old seals??
Very much aimed at all of us who feel that synthetics and old seals don't match. Interesting. [/B]

Most of the industry literature that I see on this subject says that synthetics never did hurt seals. The problem that caused leaks was that the synthetic oil tended to remove built-up deposits from seals, which in turn allowed them to start leaking.

How many of you know the trick of putting black pepper into your radiator to stop pinhole leaks (no, not on a 911). This is actually the same as when you buy the powdered aluminium ("bars-leak", etc) at the local pep-boys and pour it into the radiator. As coolant leaks from the pinhole, the small foreign particles accumulate and plug the leak.

Same physics with oil seals. Suspended contaminants in the oil will accumulate around seals and gaskets that are starting to weep. The contaminants will seal that leak much the same way as in the radiator example. Then something (like an oil with better dispersants) comes along and takes the contaminants away. Voila... a leak shows up. Was the synthetic oil the culprit, or was it just doing it's job?


At least, that's what they would have us believe....

[DW SD]

Let us know if you follow mototuneusa's advice. I don't have enough experience to dispute it one way or another.

Doug

[JeremyD]

After reading as much as I could on the subject - that's basically what I did with my engine...

[cashflyer]

Though not exactly what mototune suggests, it is basically what we already do with our V8s. When it's time for the P-3.0 overhaul (end of 2006 season is what we are hoping for) then I will definately post regarding my efforts since that will be my first Porsche rebuild.

[JP911]

I just dumped a big bottle of black pepper in my 911's oil tank. I sure hope this works! Thanks for the tip!