Suggested Break-in - New Rings

[pmonk]

Since you said in your original post that the bike started fine, then you are past the first step in break in. I would ride a bunch of those neat fm roads north and west of Tomball keeping speed varied and lots of acceleration and deceleration. I torqued my heads and reset valve clearances after my initial ride, and dumped the oil. Then about 600 miles of riding again I torqued, set valves and changed oil and filter. I really haven't found much change after the initial 600-1000 miles as far as valve clearances go, but it still uses some oil (through cc breather) but not enough to worry about.

[Manfred]

Hey Paul - good to hear from you! Before we head to church tomorrow, while most folks are sleeping late, I will head out on some good roads to follow Dan's specific guidance: "On a straight, deserted road, I put the bike in second or third gear and accelerate with wide open throttle to about one or two thousand RPM BELOW red line. I then shut the throttle and coast down, in gear, to two thousand RPM or so. I then do it again. I do this about ten times. Then I ride around for a while at an easy pace. I do this several times, if possible. This seats the rings without overheating the engine."

[ME 109]

Cranking to get an empty oil circuit fully charged is the problem with going the 'installing rings dry'. The cranking splashes oil into the bores and negates any benefit from installing rings dry. This is at least for nikasil barrels.

I am very curious about this.

if just a couple slow turns of the crank to charge the oil channels is going to splash oil into the cylinders and destroy any ring seating advantage of dry ring installation, then, how will the first couple revolutions upon startup (including however many revolutions it takes to start) be any different at all in regards to the rings?

A couple of slow turns of the crank will not charge/prime/fill an empty oil circuit. It will take 10 -15 seconds cranking to get oil throughout.
No one with an empty oil circuit is going to go straight to 3000 rpm.
I'll add from my readings over the years, it's the first seconds with the dry rings that does the trick.
More than a few of the more knowledgeable airhead mechanics on ADV recommend this method.

[Duane Ausherman]

I wish that I still had the service bulletin that suggested one wash the cylinders with soap and water, then let it rust up. Run it with the rust in place to help seat the rings. Basically, they were saying that one needed some abrasive in the engine to fix some defect.

How much "dirt" do you want in your engine on a new top end?

Check around and see how many manufacturers ever suggested running rust, or another abrasive in an engine. None.

It never became a procedure in my shop and we got rings seated anyway.

[Manfred]

I just returned from 30 mile break-in run. Several phases of 3rd gear run up to 5,200 rpm then coast down to 2,500 then back up for 8 - 10 repeats; with some easy riding in between. Runs good, oil pressure is very steady.

[Major Softie]

A couple of slow turns of the crank will not charge/prime/fill an empty oil circuit. It will take 10 -15 seconds cranking to get oil throughout.
No one with an empty oil circuit is going to go straight to 3000 rpm.
I'll add from my readings over the years, it's the first seconds with the dry rings that does the trick.
More than a few of the more knowledgeable airhead mechanics on ADV recommend this method.

I believe Manfred only changed rings and had the heads done, so we are not talking about an empty oil circuit. We are talking about the couple turns it takes to see that oil flow is still correctly getting to the rockers. Also, you said:

This needs to be done with a fully primed oil circuit so the engine can be taken to 3000 rpm immediately on start-up without molly coddling the rpm until the oil light goes out.

so I don't know why you are now talking about empty oil circuits since neither you or I were talking about that (can't find a good "confused" smiley over to the right).

"More than a few knowledgeable mechanics" have been wrong about many things before. That's why I ask the question. I'm well aware that many mechanics believe this is the best way to go. I also am pretty sure they "believe" this rather than having any certain evidence. That doesn't mean they are wrong, it just means it's worth questioning. Also, I know race mechanics believe in very hard quick break-ins of entire engines (not just top ends), but they are interested in getting an engine to max operating efficiency immediately rather than making sure it will achieve maximum life, so there are competing interests here.

[DucatiPete]

G'day,

I'll add from my readings over the years, it's the first seconds with the dry rings that does the trick.

As I'm looking at a ring job (at least) on my '79 pre-nikasil RS I was wondering if this advise is concurrent for both nikasil and iron bores?

I'm guessing it is...

pete

[ME 109]

I believe Manfred only changed rings and had the heads done, so we are not talking about an empty oil circuit. We are talking about the couple turns it takes to see that oil flow is still correctly getting to the rockers.

Having oil pressure at the big ends and main bearings is the ticket. As you say, Manfred will have that.
Perhaps I should have dealt with the case at hand, and not generalised as for a full tear down/re-build.

"More than a few knowledgeable mechanics" have been wrong about many things before. That's why I ask the question.

Quite right major. All I can say is that after reading about this subject for years, I am of the opinion that it is the optimum procedure.
Searching ADV on the subject will enlighten.

Not sure about Pete's query re cast iron bores......

[Mal S7]

I've read lots of the "start it with rings and bores completely free of oil" posts and can't bring myself to 'believe' in it.

It relies on two assumptions.

1) that this run-in will method will cause rapid wear of the high points of the rings
2) that this is a good and desirable thing to happen

I'd like to see proof. I'd like to see electron microscope pictures of the outsides of the rings that show how a few seconds of being run on a dry bore has worn it down any more than it would have done on an oiled bore. And if indeed it has (might expect that something has happened) then I'd like to know it was actually a good thing. I'd like to see that there is no sign of pick-up from any microscopic metal-to-metal welding that has done more long-term harm than good. Until then I'll go with the manufacturers advice.

Otoh I like Duane's let it rust method. Lapping paste logic makes sense to me.

[daz]

I've read lots of the "start it with rings and bores completely free of oil" posts and can't bring myself to 'believe' in it.

I'm with Mal. Call me skeptical. I just think any wear is going to take some time on those coated cylinder walls. Way more than minutes. Just my gut feeling.