Break in Procedure

[PCD]

This is a touchy subject and I'm not trying to start a war here. Someone asked me why I only gave my last GIO Quad a semi easy time for 30 minutes and then ripped it. This guy explains it better than I could.

Having over 30yrs in the precision machine shop game leads me to agree 100% with his take on modern machining technology and metalurgy though.

Now I'm old enough that it just goes against the grain to follow this guys procedure to the letter, and besides, its just some guy on the net (Bob the Oil Guy was too though and look at him now), but I've done about half a dozen 4 strokes with the 15-30 minute "take it sort of easy" time, then kill it routine and I still have 4 of them. All run great.

I am not affiliated in any way, shape, or form with this guy. Just using him for explanatory purposes.

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

[Weldangrind]

I agree that honing is different and better than in the past, and piston rings are smaller, lighter and lower tension than ever. Certainly, compression pressure on the rings forces them out to the cylinder walls, which provides the ring seal. Where I differ from this fine gentleman is that I believe the rings and cylinder wear during the break-in procedure, not just the cylinder.

That said, I've only ever held 2000 rpm for 20 minutes to establish the cam to lifter (or cam to rocker) realtionship, and then give 'er!

[Reveeen]

WELL!!!!!!!

"Rip it", or "go easy"?

I am inclined to lean closer to the manual. Running it "in" for 5 hours, avoiding "lugging it" (if that means "ripping" so be it, but I feel it important it isn't "lugged") THEN CHANGE THE OIL. Let it "rip" (still avoiding "lugging") for a further 5 hours, then CHANGE THE OIL. It should now be broken in.

[PCD]

I agree that honing is different and better than in the past, and piston rings are smaller, lighter and lower tension than ever. Certainly, compression pressure on the rings forces them out to the cylinder walls, which provides the ring seal. Where I differ from this fine gentleman is that I believe the rings and cylinder wear during the break-in procedure, not just the cylinder.

That said, I've only ever held 2000 rpm for 20 minutes to establish the cam to lifter (or cam to rocker) realtionship, and then give 'er!

We are in a bit of a pickle because we dont know the hardness of the cylinder liner used in out little engines, but I can tell you that about 15 years ago Jap cars started using steel comression rings around 50RC and up even. I have seen this myself with a Rockwell hardness tester.

Then they even got in to Nitriding the things, but thats another kettle of fish.

I believe the ring wears aslo, but at a much slower rate if its a steel ring as most are these days (compresssion anyways, dont think the oil ring matters too much, if we even have one!).

[TurboT]

Ahh shit.. let it get some heat in it and then stomp on it.. WTF!

If there's a defective rebuild or part it'll eat itself right away anyhow, under any method. 8)

[PCD]

WELL!!!!!!!

"Rip it", or "go easy"?

I am inclined to lean closer to the manual. Running it "in" for 5 hours, avoiding "lugging it" (if that means "ripping" so be it, but I feel it important it isn't "lugged") THEN CHANGE THE OIL. Let it "rip" (still avoiding "lugging") for a further 5 hours, then CHANGE THE OIL. It should now be broken in.

Not for me.
I change the oil after the first 5-10 minutes and I think its crazy not to. My belief is 80% of the metal particles are chewed off in the first 5 minutes. I've seen too much silver metalflake colored oil to think otherwise.
Granted, I'm 51 and have found it very difficult to change my old fashioned thinking, but i have to believe my own eyes.

[PCD]

Ahh sh--.. let it get some heat in it and then stomp on it.. WTF!

If there's a defective rebuild or part it'll eat itself right away anyhow, under any method. 8)

Where is the "thumbs up" icon when you need it ;)

See, now thats another area I DONT believe the manual on. Take a modern car engine "There is no benefit to warming up the engine before driving, it is not needed" HA HA HA....never in a million years bud. I let it warm up regardless of what the manual says.

EDIT: I dont think I'll ever be able to change my thinking on this one unfortunatly. Pump up lifters, broken rings, clattering valves...i just cant get that old fashioned stuff out of my head even though (again) modern tech has probably eliminated all of the drawbacks to running cold.

[TurboT]

Motors and metals and parts of today are so far ahead of what they once were I think mostly the conventional or old school way of doing things has changed.

The rings are better manufactured, the cylinder walls are either some strange new metal or have been bored and honed much more accurately, and measured much more accurately than ever before.

I mean, I was grinding crankshafts making every journal the same size, with virtually no taper or out of roundness evident. When I say same size, I mean exactly to .0001. I'd be pissed if I had any variation beyond that. I'd seen aftermarket 'race' cranks come in that were of lower quality in terms of size and shape than what I was expected to turn out.

This goes for all the machining work in most machine shops in the province. (Some bad, but most did a good job)

My point here is the motors of today are not loosely slapped together with dirty parts and crappily machined parts and I expect most of the 'relationships' between metals are established very quickly because of this.

[PCD]

Motors and metals and parts of today are so far ahead of what they once were I think mostly the conventional or old school way of doing things has changed.

The rings are better manufactured, the cylinder walls are either some strange new metal or have been bored and honed much more accurately, and measured much more accurately than ever before.

I mean, I was grinding crankshafts making every journal the same size, with virtually no taper or out of roundness evident. When I say same size, I mean exactly to .0001. I'd be pissed if I had any variation beyond that. I'd seen aftermarket 'race' cranks come in that were of lower quality in terms of size and shape than what I was expected to turn out.

This goes for all the machining work in most machine shops in the province. (Some bad, but most did a good job)

My point here is the motors of today are not loosely slapped together with dirty parts and crappily machined parts and I expect most of the 'relationships' between metals are established very quickly because of this.

With you 100%.
Dont neglect the advances in Engineering and CAD stuff either. 25yrs ago all that was around, but VERY esoteric and insanely expensive. The hardware to run it was out of reach of all except VERY large companies like the big 3.
Now anyone can buy a moderately powered desktop and run ACAD or CATIA, or any other spiffy modelling software.
Desin your engine, model it, modify, build.

[TurboT]

With you 100%.
Dont neglect the advances in Engineering and CAD stuff either. 25yrs ago all that was around, but VERY esoteric and insanely expensive. The hardware to run it was out of reach of all except VERY large companies like the big 3.
Now anyone can buy a moderately powered desktop and run ACAD or CATIA, or any other spiffy modelling software.
Desin your engine, model it, modify, build.

Bang on dude. Things today are built quicker, cheaper, and more accurately than ever. I mean really, I've got two complete running motors with wheels and handlebars in my back yard, and I got them both here for under 500 bucks. How is that even possible??

I spent 13 years in a motor building shop and I can't recall a motor came back for warranty work because of a 'bad break in procedure' Not EVERYONE could be doing the exact same thing, we used many different installers, and had many different repair shop customers. Everybody gets set in there ways and does something a little different.

Don't get me started on the stupid things people would do to fuck up a perfectly good rebuilt motor, and then blame the engine builder, but that is not about break in. 8O

We'd spin these buggers over hundreds of times on the engine stand during assembly and check over, the things were pumping air on the first turn, over and over again.. wouldn't surpise me if those relationships were established on the engine stand, mostly, before it ever saw an explosion.

Just my .02c here.

[Weldangrind]

Just my .02c here.

And worth every penny, T. :lol:

As a semi-hijack, Sam and I finished honing the XR200 cylinder and filing the new rings last night. I measured the bore and found no taper or out-of-roundness, despite the cylinder being at the outer edge of tolerance (according to the shop manual). Despite that, both top rings took over 40 passes with a file to attain the 0.50mm gap clearance.

That much filing and the fact that the top two rings have exactly the same profile surprised me. There is no typical wedge profile or anything; these rings are totally square edged, and they're Honda rings.

Back to your regularly scheduled post. :D

[FastDoc]

Having over 30yrs in the precision machine shop game leads me to agree 100% with his take on modern machining technology and metalurgy though.

Problem is the Chinese engines are made of tofu and goat cheese.

The break in for my Q's was ridiculous, 3,000KM 8O . I did it their way to be on the safe side, but it seemed silly to me. My guess is to keep the bike at such a low stress level it would have no chance of puking in the 2 year warantee period. 8)

[PCD]

Having over 30yrs in the precision machine shop game leads me to agree 100% with his take on modern machining technology and metalurgy though.

Problem is the Chinese engines are made of tofu and goat cheese.

The break in for my Q's was ridiculous, 3,000KM 8O . I did it their way to be on the safe side, but it seemed silly to me. My guess is to keep the bike at such a low stress level it would have no chance of puking in the 2 year warantee period. 8)

Maybe.

Then again, maybe not. ;)
http://imgnews.naver.com/image/028/2007/03/27/04032081_20070328.JPG
http://www.futurefirepower.com/wp-content/photos/orig_Type_99.jpg
http://www.jeffhead.com/redseadragon/2009-PLAN-Type094-02.jpg

[FastDoc]

Alas, the downside of enjoying cheap Chinese bikes. :x