break-in oil

[bmad]

Is there such a thing as "break-in oil" for a new engine? I was thinking of doing the first oil change after only 200 miles, or should I wait for the 500 mile mark

[Red01]

It can't hurt to do it @ 200.

As far as "break-in" oil, I'd still use a good quality dino oil during break-in and save the synthetics, if desired, for afterward. Maybe that's old school nowadays, since some vehicles are delivered with synth inside when new, but that's what I'd do on any fresh motor I built.

[pmackie]

Not really much need for a "break in" oil any more. Back in the "good old days" you had to make sure that the piston rings got properly seated into the liners. Usually Chrome rings and iron liners.

Most new engines have much more sophisiticated alloys now. The important thing about breaking in a new rings is to ensure that you have sufficient cylinder pressure to keep the rings pushing into the cylinder walls. This is why you should avoid idle and steady throttle. Steady acceleration is best for keeping up cylinder pressure, so you want to run through the gears, gently accelerating as much as possible, slowly increasing the revs as the miles increase.

So...do you need to change the oil? Initial breakin will cause an increase in metallic particles in the oil, so you want to change it. But 500 milies is not a lot of miles. Nothing wrong with changing early, but don't fuss about it.

Synthetic oils based on PAO (or SHC) technologies won't interfere with break in either. I would suggest you wait until the 500 miles and then change to your favourite oil. (Esso XD-3 Extra 0W40 for me).

(But oh, by the way, if you are rebuilding a 50's vintage John Deere tractor, you likely WILL need a break in oil. Something like Esso Mineralube.)

[Ranger]

[solman]

I don't know if this applies to all new bikes, but there is talk about not doing break-ins at all and just going for it.  At least I have heard that for sport bikes, or doing a more aggressive break-in.  I know that some bikes have liners or something in the cylinders that resists wear and tear.

[Ranger]

[pmackie]

I don't have any experience with the water cooled sport bikes (I'm a 70's mechanic...only water cooled bike then was the Suzuki 3cyl water buffalo!!). However, all the recent (past 20 years?) dirt bikes have been water cooled, so I assume the new sport bikes use similar technology, some of you more recent guys can feel free to correct me if I am mistaken.

Basically new water cooled designs now use some form of ceramic spray on liner over the aluminium cylinder (Nickel Silicone Carbide for eg). This stuff is hard as diamond, as basically does NOT wear. This means you now need softer rings. So...breakin now means getting the rings to seat to the hard cylinder liner, which happens much more quickly, but the basics still apply. You need to breakin using sufficient cylilnder pressure to keep the rings pushed into the cylinder wall, so avoid idle and steady throttle, and try to accelerate gently through the gears as much as possible.

The 2nd breakin item is getting the piston when hot, to wear into the cylinder. Because the ceramic liner is so thin, the cylinder and piston basically expand as similar rates (compared to old style iron/steel liners) which means you can have tighter piston to cylinder clearances. So...you need some heat cycles to expand the whole top end so any "high spots" can wear in. Again, on a new water cooled design, this takes less time than on old air cooled engines.

So...for either design;
1. Let it get hot and cool down a bunch of times.
2. Try to accelerate gently, as much as possible, increasing the revs as the mileage accumulates.
3. Change the oil to get rid of the accumulated metal particles.

[CWO4GUNNER]

Most manufacturers still warn of using any type of friction reducing or synthetic oils before the break in period so that the engine working surfaces can break in and the term we use in gun smithing "match" properly. So I use the manufactures recommended oil for the first 300 miles and change both oil and filter with the same type mineral oil, then at 1000 miles change them all again but use Super Tech all synthetic for only $12 for a 5 quart bottle.

[Ranger]

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[Blade]

I would recommend staying with a good petrolium base oil for the first 4K miles and then switch to synthetic oil if you want. This will ensure that everything in the engine is fully mated properly.

1st oil change at 600 miles
2nd oil change at 2K
3rd at 4K.

This is my opinion.