When to switch to synthetic...

[bratt]

With my 03yz250f I ran Amsoil sythetic it's whole life, I have 5 hours on my 06 yz250f and want to switch from the yamalube back to the amsoil, is 5 hours enough time to do the swap? (Bike is currently on it's 3rd oil change)

Thanks,

Gina

[SUnruh]

as long as you think the rings are fully seated, you can switch.

others will say you can switch sooner (even though i personally had amsoil NOT let the rings seat) and some will say longer.

so when you feal it is time, go ahead. just beware they if they don't seat, there is only one fix -> re-hone cylinder and new rings.

[Stripes123]

30-60 minutes at variable load is usually sufficient

[bratt]

The bike has been raced for 2 hours of it's life so far at the "b" level if that makes any difference.

[txfour]

The bike has been raced for 2 hours of it's life so far at the "b" level if that makes any difference.

If that's the case, you are good to go. I am an Amsoil dealer and though I like to use my own stuff, I waited until I had a couple of hours of hard use on the bike.

[grayracer513]

0 hours is enough time. There is no reason whatever not to use synthetic oil during breakin.

[Stripes123]

0 hours is enough time. There is no reason whatever not to use synthetic oil during breakin.

I disagree

[mattoak]

I disagree

Disagree with gray

Certain death

haha jk

[txfour]

The age old when do I switch / what oil do I use deabte. Gray is a smart fellar and knows his stuff. Lucky for you the decision is easy as you already have 2 hours race time on your machine. Switch and be done with it.

[intensem1rider]

I agree with Grey, the rings are going to rub the cylinder walls no matter what. In expensive cars they use synthetic oil from day one except they have an additive added to aid break in.

[Matt96xr6]

I never have run anything but Amsoil in my bike. Came home, tore down the motor and swapped to synthetic before even starting the bike.

Same thing with my 05.

[Stripes123]

I just had my engine rebuilt by someone who builds racing engines for a living and his recommendation was to use Rotella dino for the first 30-60 minutes then switch over to Mobil 1. I'm not an expert but I am smart enough to listen to someone who is.

[sambo808]

sorry if i sound like a noob but if im not racing do i have to use synthetic?

[txfour]

You dont have to switch even if you are racing. However, it is very cheap insurance for an otherwise expensive engine.

I know several people that run dino oil in their bikes and they have no problems. For me, knowing the oils and what makes synthetics out perform the dino's, gives me piece of mind.

I will run two harescrambles (4 hours) between oil changes using Amsoil 20W-50.

[grayracer513]

I disagree

By all means, feel free to do so. However, I do have about 20-25 years of using synthetic oils in brand new engines to back this up with, and not a single failed ring set in all that time.

If you give any thought to it, the suggestion that that you shouldn't use synthetics in a new engine gets sillier the deeper you look. The underlying concept would seem to be that synthetics lubricate too well and prevent the rings from seating. First off, this is an admission that synthetics lube better. But does it seem like a good idea, then, to deliberately reduce the amount of lubrication delivered to the cylinder walls, main bearings, etc., during this time when they have not yet worn to match each other?

A microscopic look at the "perfect" surface of a new crank pin and bearing will reveal a surface that will remind you more of the Eastern Rockies than of a polished table top. In operation, these two "jagged" surfaces will be separated by the film of oil between them, and it is absolutely important that the two parts, such as a rod and a piston, never touch each other. Ever. The result of such contact is scoring and major surface damage.

Over time, the two parts do wear, but how does that happen if the parts never touch? Well, in the first place, they do, a little. When placed under sudden loads, and very often when cold started, the oil film will fail to keep the parts totally separated, and the highest of the surface imperfections (called asperities) will come into contact with each other. (This incidentally, is were the boundary lube additives like zinc and phosphorus come into play) The fact that this does happen does not make it desirable, however, and better oil avoids it to a greater extent than a poorer one.

The other way that parts wear is that the oil itself wears them. You find this a bit outrageous, I'm sure, but ask yourself this: does oil eliminate all friction? No, it doesn't. Now add to that the fact that we deliberately avoid ECII oils that have reduced friction so that our clutches will work right. It takes a long time for it to happen, but after a while, our crank pin and bearing will have a near mirror finish, and a microscopic exam at that point will show a general smoothing over of the surfaces, which actually makes it easier for a lower grade oil to lubricate effectively. But the oil has to be what does this, not the failure of a lesser oil to keep the parts out of mutual contact. So again, given that, why use less than the best oil you could during the first critical hours?

The answer often given is that a better oil will not let the rings seat, to which I reply, well it's not polite, so let's just say I think not. Rings fail to seat because either the cylinder was not machined and/or finished correctly, because they were installed on a used piston in which the ring grooves were excessively worn, or because they were not run hard enough in the initial stages of their service life. The question of which engine oil is used simply does not enter into it, because there is almost no oil at all at the compression rings in operation. Part of the reason the use of a cross hatch finish is important is so that ring will oil its entire wearing surface more uniformly, and an oil film between an oil ring and the cylinder actually helps it seal. The chrome-edged (typically), thin rails of the oil scraper rings remove nearly all of it, and do so almost immediately with little or no run in time. To give you an idea of how little there is, a single cylinder four stroke operating at 6000 rpm on the average that gets 0.00056ml of oil in the combustion chamber each time it fires will burn a half liter of oil in 5 hours. Does yours do anything remotely like that? How far do you imagine that half a micro liter will go in terms of slicking down the entire surface of a pair of compression rings?

Most modern high performance piston rings are moly filled, meaning that their outer edge is slightly hollowed during their manufacture and filled with a hard molybdenum coating, which is at once extremely hard, and also self lubricating so that it can run in the near absence of any oil and still seal and wear well.

The oil additives used in Chevrolet Corvettes, which are built, filled with Mobil 1 and shipped with no further ceremony is GM's Engine Oil Supplement, which is used in most of their new cars regardless, and is put there to address the fact that the car is apt to sit for several weeks after being built and/or sold. It helps an oil film stay in place on an unused engine's internals, that's all.

[SUnruh]

By all means, feel free to do so. However, I do have about 20-25 years of using synthetic oils in brand new engines to back this up with, and not a single failed ring set in all that time.

um, so what.

Eric Gorr has more years than that doing just bikes and he says NOT to.

2 sides of the coin.

[grayracer513]

Eric Gorr has more years than that doing just bikes and he says NOT to.

With all respet due to Mr. Gorr, and you, for that matter, that's very nice, but it does nothing to diminish the success I've had in ignoring that particular piece of advice, nor does it explain every Corvette built since about 1986.

[txfour]

Someone told me that vettes are broken in at the factory. Don't know if this is true or not, but I have heard this a couple of times.

[grayracer513]

It isn't true. The engines are assembled with only the assembly oil and shipped otherwise dry to the car assembly plant, where they are installed and filled with oil for the first time. At the end of the line, one of the more talented UAW types fires it up, and with no ceremony whatsoever, zooms off across the parking lot and lines it up with the other finished units. Other than that, the only break-in the get is about a 20 second low speed dead spin at the engine plant.

[455]

I use synthetic right from the start after a rebuild and have had no problems. But I think the key is a message on the back of a bottle of Red Line oil for example. They recommend not using their oil for break in unless the engine is run aggressively within the first 10 minutes.

I always build wet with synthetics, break in aggressively, and have never ever had a problem, 2 or 4 stroke.