How Do Rings Bed In?

[Winston001]

I was talking to an engineer today and he referred to the bedding in of rings to create a perfect seal with the cylinder sleeve. Always heard about this but how does it actually work? Why doesn't it work sometimes? How does "running in" an engine help?

I enjoy learning about this stuff.

[Drew]

When the cylinder sleves are put in, they are scuffed up with a stone, which works like sand paper, so when the the rings first start gonin up and down past tehm they wear a bit to the exact shape of the bore.

Nowadays the running in thing is actually less for bedding in, and more a safety period incase something is very wrong, at least that is what I've heard from some reliable sources.

[homer]

It also allows for the heating and cooling effects in the engine
allows the working parts to polish and lets them get used to being placed under stress

Lets say i run over you foot

And lets say i do it another 100 times an hour later
do you think it will hurt more the first time or later on

[Motu]

The piston rings and cylinder go to bed together (with your permission of course) They pump up and down together quickly,generating heat....if they go too fast it's all over very quick and everyone is disappointed.By varying the speed the process can be extended.....and it all becomes very blissful and everyone is happy.

Rings can't go to bed with other rings,and cylinders can't go to bed with other cylinders - in the engineering world we have rules,and you cannot break them,no matter how hard you try.

[homer]

The piston rings and cylinder go to bed together (with your permission of course) They pump up and down together quickly,generating heat....if they go too fast it's all over very quick and everyone is disappointed.By varying the speed the process can be extended.....and it all becomes very blissful and everyone is happy.

Rings can't go to bed with other rings,and cylinders can't go to bed with other cylinders - in the engineering world we have rules,and you cannot break them,no matter how hard you try.

Yeah thats very clever

[Winston001]

You guys are great. Here I am laughing my head off having been gently threatened with pedial assault by Homer to illustrate his point, only to read Motu's classic description of how it all works. :eek:

[homer]

oops yeah
well its just to give the idea
i was laughing at the time as well

Where does that leave the lord of the rings
is he situated at the top

[Ixion]

The piston rings and cylinder go to bed together (with your permission of course) They pump up and down together quickly,generating heat....if they go too fast it's all over very quick and everyone is disappointed.By varying the speed the process can be extended.....and it all becomes very blissful and everyone is happy.

Rings can't go to bed with other rings,and cylinders can't go to bed with other cylinders - in the engineering world we have rules,and you cannot break them,no matter how hard you try.


Yeah? Wot abart the Knight sleeve valve engine then ?

[Motu]

Yeah? Wot abart the Knight sleeve valve engine then ?

That's a strap on.....one of the cylinders has to turn onto a piston.

[Winston001]

Enough of this levity and general chuckleheadeness. I have questions. :crazy:

So a piston reciprocates within the cylinder. The rings touch the sides and flatten off high spots during the first few hundred thousand cycles. At this stage the motor is referred to as tight. Fine.

Pistons do not simply reciprocate up and down. There are lateral forces transmitted by the conrod to the gudgeon and thence to the sides of the pistons. The conrod converts a turning force from the crankshaft into a vertical force but there is some sideways pressure.

So logically, since the lateral forces only go to each side, the bore should become slightly oval. Right?

But rings are floating. How can they turn and flex and move yet form a seal if the shape they are forming changes every 90 degrees? :dodge:

[Ixion]

It is actually more complex than that, in fact the crystalline structure of both a (new) bore , and the rings is usually changed in the process.

Not all rings float, two stroke rings are usually pegged as are some four strokers.

But in general terms you are right. Bores do become slightly oval with wear (in fact that is the most precise measure of bore wear, and why a hone on a lightly worn bore improves it ). And the ovality (though bear in mind that rings are flexible) no doubt is a major contributor to ring wear.

[jonbuoy]

I believe its the gasses from the explosion trying to force their way past the rings that pushes them out onto the bores and makes an even tighter seal. They do move and wear the bore and piston on the thrust faces - you can see scoring marks on the piston skirts to show this. Still amazes me that engines can be so reliable when you think of all that metal on metal contact and only a wee film of oil between them.

[007XX]

I just want to ask something, pretty please:

So, when someone says that the bike runs better after the running in period, is that because the bore has now become smooth(er) and is offering less resistance to the rings?

*and Motu's explanations rocked! :2thumbsup*

[imdying]

Hush woman! The men are speaking bikes! :rofl:

But yeah, that and lots of little bits all gelling together nicely.

[007XX]

Hush woman! The men are speaking bikes! :rofl:

.

You talk to your momma with that mouth? :spanking:
And there was I, trying to learn and take part in a serious bike thread...That''ll learn me! <_<

Now, back on topic...does the "bedding in" time vary from bike to bike? For example: would a Vtwin take longer than a normal in line four?

Reason I ask: still doing research for potencial next bike.

[imdying]

Yeah, some do... a 2 stroke GP bike might blow up after 200kms, so naturally you're not gonna run it in for 1500kms :no:

It's not really a biggy, after a few hundred kms you can give a bike plenty of stick, and as most bikes have plenty of poke in the midrange, its not like the waiting period is the end of the world :)

It is insignificant enough that I would not let if affect your next bike purchase, just get the one that makes you happiest.

[007XX]

Thanks Imdying:niceone:...I guess I was just trying to ascertain if there was to be a hard fast rule on how long you should allow for any bike.

But I guess I'll just have to make sure I ask at time of purchase, for whatever bike I purchase in the future.

As you said, no biggie, but I do like to know these things.

[Ixion]

..

Now, back on topic...does the "bedding in" time vary from bike to bike? For example: would a Vtwin take longer than a normal in line four?

Reason I ask: still doing research for potencial next bike.


Dunno about bike to bike but the bedding in time certainly varies from chick to chick.

[imdying]

But I guess I'll just have to make sure I ask at time of purchase, for whatever bike I purchase in the future.NZ is full of monkeys, just read the little book they give you with the bike :)

[chanceyy]

ahhh I guess i should have read this thread a few weeks ago ... Betsy has new rings installed .. As i had not ridden for a month .. took it a bit quietly anyhow .. so prob ran about 400 ks pretty quietly ... now back to giving her the good ole two stroke thrash .... or should i still be taking it quietly with her ????

yeah another female jumping in on male discussion ..

bling to motu as well - that was classic

[007XX]

Dunno about bike to bike but the bedding in time certainly varies from chick to chick.

:pinch: Must resist temptation to be strumpet...Gggnnnnnn! Ixion, you sadistic bugger you! :eek:


NZ is full of monkeys, just read the little book they give you with the bike :)

Good suggestion...I have had more than my fair share of problems with mechanics, hence the fact I'm trying to learn more...It's really pissing me off as they must see me coming a mile away with "rip her off" written on my forehead!

[vifferman]

So, when someone says that the bike runs better after the running in period, is that because the bore has now become smooth(er) and is offering less resistance to the rings?
Partially. It's bit like the losing of virginity for the bike: all the tightly-fitting things in the engine become a bit less tight. This includes the piston and ring clearances to the bores increasing slightly, and plain bearings elsewhere in the engine also becoming fractionally less tight fitting. All those slight bits of drag add up, so when the engine 'loosens up', there's less resistance to things turning or going up and down or back and forth.

[007XX]

Partially. It's bit like the losing of virginity for the bike: all the tightly-fitting things in the engine become a bit less tight. This includes the piston and ring clearances to the bores increasing slightly, and plain bearings elsewhere in the engine also becoming fractionally less tight fitting. All those slight bits of drag add up, so when the engine 'loosens up', there's less resistance to things turning or going up and down or back and forth.

That makes sense...so apart for driving within a certain range of revs only, is there anything else one has to do to help with the loosening up?

And if anyone mentions KY jelly, I'll get :mad:...I'm trying to be serious here people!

[chanceyy]

Good suggestion...I have had more than my fair share of problems with mechanics, hence the fact I'm trying to learn more...It's really pissing me off as they must see me coming a mile away with "rip her off" written on my forehead!

ohh goodie so I am not the only one .. it really really farks me off... ok must step off soap box now .. :argh:

[007XX]

ohh goodie so I am not the only one .. it really really farks me off... ok must step off soap box now .. :argh:

:eek: Don't get me started...I feel your pain.

[imdying]

That makes sense...so apart for driving within a certain range of revs only, is there anything else one has to do to help with the loosening up?I hear KY helps.... :innocent::shifty:

[007XX]

I hear KY helps.... :innocent::shifty:

You're lucky you ride an SV...<_< That is your only salvation at this point :bleh:

[vifferman]

That makes sense...so apart for driving within a certain range of revs only, is there anything else one has to do to help with the loosening up?
The two main things are to not labour the engine (too high a gear or too low revs for the speed) and not thrash it too much. Also it's not recommended that synthetic oil is used (hence KY jelly is out) until the engine's "a bit more experienced". :rolleyes: Worm on the street is that this is because the synthetic erl is a bit short on detergent properties.

Modern engines are (by and large) made to pretty exacting tolerances. In the Olde Dayes, there were all sorts of daggy little bits in the engine that needed to be worn off, so a special "running in" oil was used, and this was discarded after a few hundred leagues. Nowadays, the oil is still changed after the first 600-1000km, but as far as I know it's just ornery oil.

[imdying]

You're lucky you ride an SV...<_< That is your only salvation at this point :bleh:You should try an RGV, makes the SV1k look positively boring to ride :yes:

[007XX]

The two main things are to not labour the engine (too high a gear or too low revs for the speed) and not thrash it too much.

Thanks Vifferman, I know I can always count on you for knowledge...:niceone:


You should try an RGV, makes the SV1k look positively boring to ride :yes:

But...but...it ain't got the "doof, doof"...I am (and probably always will be) a Vtwin girl.
And a SV1K boring???? wash your mouth with soap, young man :spanking:

[imdying]

But...but...it ain't got the "doof, doof"...I am (and probably always will be) a Vtwin girl.It is a v twin... just not a ghey diesel one :second:

And a SV1K boring???? wash your mouth with soap, young man :spanking:Compared to an RGV, it is... sorry :scooter:

[007XX]

Compared to an RGV, it is... sorry :scooter:

Ok then, if you say so...Mind you, with my riding proficiency, anything going faster than 130 k/hr is exciting :o

I am so easy to please.......when it comes to bikes of course! :p

So I guess someone who would hit the rev limiter on a brand new bike would not be doing it any favours then?
How much damage could it actually do?

PS: not that I would do it, but I saw this woman do it to a brand new CBR600 at the Cold Kiwi and hated her for it! Cos I want her bike, maybe...

[Ocean1]

Materials and manufacturing tolerances have improved a lot, what works for a cast iron bore doesn't nescessarily work for a modern hard chrome bore with a mirror-like finish from the factory.

If you look long enough you'll get a full set of conflicting advice from a range of genuine experts. I tend towards this guy's thinking. Mostly. Unless I don't agree with that bit...

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

[007XX]

Hmmm, ok thanks for that...

I shall get the in-house engineer to have a read up and make my mind up for me on this! :D

[vifferman]

Thanks Vifferman, I know I can always count on you for knowledge...:niceone:
Oh - you were probably misled by my removal of the "and that's what I think.. or something.. or not... dunno really..." signature line.

I just make stuff up. :confused:



But...but...it ain't got the "doof, doof"...I am (and probably always will be) a Vtwin girl.
Yeah, y'get that.
It started for me when I first saw/heard the original Ducati 750SS, then was really rammed home when I first heard a 916 with Termignonis, and having owned a v-twin, I now know what it's all about. :yes:
Must get me another one, one time...

A V4 is a case of "close, but no cigar..."

[vifferman]

Materials and manufacturing tolerances have improved a lot, what works for a cast iron bore doesn't nescessarily work for a modern hard chrome bore with a mirror-like finish from the factory.
Yes... there is that.
I guess the rings still need to bed in a bit, and the engine parts go through a few heat cycles. But a pressed-in nicasil bore isn't going to change appreciably in the first 50,000 km or so...

[007XX]

Oh - you were probably misled by my removal of the "and that's what I think.. or something.. or not... dunno really..." signature line.

I just make stuff up. :confused:

Nuh uh, I don't buy it...but nice try El Humblo! :clap:



Yeah, y'get that.
It started for me when I first saw/heard the original Ducati 750SS, then was really rammed home when I first heard a 916 with Termignonis, and having owned a v-twin, I now know what it's all about. :yes:
Must get me another one, one time...

A V4 is a case of "close, but no cigar..."

Exactly...there is just a magic about the sound of it, the way the engine braking power assists, the rumbling of that engine under the rider, the way it just howls out of corners...:love:

:drool: 'scuse me, I think I need a moment here...:sweatdrop

[vifferman]

Exactly...there is just a magic about the sound of it, the way the engine braking power assists, the rumbling of that engine under the rider, the way it just howls out of corners...:love:
You get a similar flat drone from the V4 - I like employing "excessive or unnecessary acceleration" just so I can decelerate excessively to hear that noise.
But the howl at >8000 rpm when the Satantune's got the spud out lifts the hairs on the back of your neck in a way a v-twin doesn't.

[Ocean1]

...the way the engine braking power assists...

Smatter of fact I could do with a bunch less assistance there, tad too exciting occasionally. :baby:

Suppose I could refrain from stomping it down two gears way too late also... :Oops:

[more_fasterer]

Materials and manufacturing tolerances have improved a lot, what works for a cast iron bore doesn't nescessarily work for a modern hard chrome bore with a mirror-like finish from the factory.

If you look long enough you'll get a full set of conflicting advice from a range of genuine experts. I tend towards this guy's thinking. Mostly. Unless I don't agree with that bit...

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

What he says seems to make a lot of sense... when you consider that brand new bikes get thrashed to the limits on a press launch without blowing up, you've certainly gotta wonder just how bad using the bike's full potential can be - as has already been said, it's more to run-in the rider.

[007XX]

You get a similar flat drone from the V4 - I like employing "excessive or unnecessary acceleration" just so I can decelerate excessively to hear that noise.
But the howl at >8000 rpm when the Satantune's got the spud out lifts the hairs on the back of your neck in a way a v-twin doesn't.

I got to admit *sorry, hang on, 1098 going past my work...*
, that i did enjoy the sound of your bike that time you rode past me.:niceone:

But yeah, I definitely play with the acceleration and deceleration of my bike, just to enjoy the sound, especially in a tunnel...

[Ocean1]

What he says seems to make a lot of sense... when you consider that brand new bikes get thrashed to the limits on a press launch without blowing up, you've certainly gotta wonder just how bad using the bike's full potential can be - as has already been said, it's more to run-in the rider.

Actually, I suspect some of the more outrageously extended requirements are intended soley to minimise warrantee claims.

For me, with a modern road engine it’s enough to avoid the top 10% of the rev range and don’t lurk at the same rev’s or load too long.

[007XX]

Smatter of fact I could do with a bunch less assistance there, tad too exciting occasionally. :baby:
Suppose I could refrain from stomping it down two gears way too late also... :Oops:

:laugh: It's like a whole new riding experience, isn't it?

Not that I am that experienced, but a few people I spoke to told me they were a bit shocked at the difference when riding a Vtwin for the first time.

Ya got to be gentle...make her purr instead of bark til you've got her tamed...Or so I'm told! :whistle:

And how long did it take you to break her in? Or did you apply the rules of that guy you gave us the link to?

[Sully60]

Nuh uh, I don't buy it...but nice try El Humblo! :clap:




Exactly...there is just a magic about the sound of it, the way the engine braking power assists, the rumbling of that engine under the rider, the way it just howls out of corners...:love:

:drool: 'scuse me, I think I need a moment here...:sweatdrop

Sorry for going:
:Offtopic:
You need a set of my custom and highly illegal twin open megaphones on that little VTR.

Like these that I prepared earlier
http://www.kiwibiker.co.nz/forums/showpost.php?p=1300908&postcount=1852

http://www.kiwibiker.co.nz/forums/showpost.php?p=1312282&postcount=9

I thought it was pretty awesome just revvin it wild in the driveway, but the first time I shut the throttle at 11 grand ohhh....:drool::drool::crazy:

A v-twin with these would just be da bomb, and probably much louder than one!

Warning, these exhausts render the noise dampening effects of earplugs to levels were the earplugs need earplugs!

Back on topic , this issue has got to be the one where you'll here the most difference in terms of opinions.
A highly respected mechnic once told me about running in a race bike at the track from brand new. Two practice sessions, no lugging , no thrashing, changed the oil, full race pace from there and it was the fastest of all of the bikes in that team.
Then the rider rolled it into a little ball!

[Ocean1]

And how long did it take you to break her in? Or did you apply the rules of that guy you gave us the link to?

I didn't, she was "pre-loved".

But yes, as I said I've used that general principle for longer than he's been publicising it. I am a tad more concious of oil temp with a new engine though, some are easy to overheat for a while...

[more_fasterer]

Very good point there Ocean1 about the oil temp.


You get a similar flat drone from the V4 - I like employing "excessive or unnecessary acceleration" just so I can decelerate excessively to hear that noise.
But the howl at >8000 rpm when the Satantune's got the spud out lifts the hairs on the back of your neck in a way a v-twin doesn't.

:yes: :yes: :yes:

[smoky]

A new engine from a shop will already be prepped ready to go – ride it – by the time you get use to it and want to start pushing the motor it will be ‘bed in’. Just avoid labouring it (being in too lower gear)

If you however rebuild your own engine this is my approach; (haven't done it in years)
First time I fire it up – I give about 2000 RPM watching the oil pressure light (fit a gauge if you can) – checking temperatures and for any fluid/oil leaks – for about 20 minutes. Shut off and change the oil, reset tolerances – valving, check static timing, head bolts/nuts torque – bla bla. Then run up to idle and tune.

Take it for a blast – get it nice and hot driving it hard (not valve bouncing or anything) – a good windy hill road opening it right up, load the engine up a bit. Depending on the engine I have run hotter plugs while doing this.
Getting it hot and loading it up will burn the glaze off the cylinders and everything will ‘seat’ and bed in – 300 ks’ should do it.
Repeat the oil change and valve adjustments
Real fussy dudes worry about running up a new engine on un lubed valve springs, or a non ‘work-hardened’ cam and will often use a lighter set for run in and then replace them after 300 ks or so – never been that fussy myself.

[007XX]

Sorry for going:
:Offtopic:
You need a set of my custom and highly illegal twin open megaphones on that little VTR.

Like these that I prepared earlier
http://www.kiwibiker.co.nz/forums/showpost.php?p=1300908&postcount=1852

http://www.kiwibiker.co.nz/forums/showpost.php?p=1312282&postcount=9

I thought it was pretty awesome just revvin it wild in the driveway, but the first time I shut the throttle at 11 grand ohhh....:drool::drool::crazy:

A v-twin with these would just be da bomb, and probably much louder than one!

Warning, these exhausts render the noise dampening effects of earplugs to levels were the earplugs need earplugs!

And what makes you think my little VTR hasn't got after market pipes on already, Oh Wrongly Assuming One?

Ask anyone who's ridden with me before...my girl sounds Reeeaaaaall good :2thumbsup

[007XX]

I didn't, she was "pre-loved".

But yes, as I said I've used that general principle for longer than he's been publicising it. I am a tad more concious of oil temp with a new engine though, some are easy to overheat for a while...

Indeed...i could be wrong, but I was told this was especially an issue with Triumphs, they definitely do not like to overheat.

This was also a reason for my questions, as I am very tempted by a 675 Daytona...Mind you, if I was to buy myself such a little gem, I would spend any length of time required by the manufacturer to do it properly, no questions!

[Sully60]

And what makes you think my little VTR hasn't got after market pipes on already, Oh Wrongly Assuming One?

Ask anyone who's ridden with me before...my girl sounds Reeeaaaaall good :2thumbsup

I knew it did, I saw it on your profile pic before your changed it to the lovely picture yo've got now. Very cool btw Twin mufflers and all that, very balanced look from behind.

But you don't have a set of hand made NWM custom loudening pipes to scare the shit out of the entire Norf Shore though.

[Ocean1]

Indeed...i could be wrong, but I was told this was especially an issue with Triumphs, they definitely do not like to overheat.

This was also a reason for my questions, as I am very tempted by a 675 Daytona...Mind you, if I was to buy myself such a little gem, I would spend any length of time required by the manufacturer to do it properly, no questions!

Lot of the more serious sprotstoys are bloody light, one of the ways they get there is trimming coolant and oil volumes. Some of them are easy to cook.

[007XX]

I knew it did, I saw it on your profile pic before your changed it to the lovely picture yo've got now. Very cool btw Twin mufflers and all that, very balanced look from behind.

But you don't have a set of hand made NWM custom loudening pipes to scare the shit out of the entire Norf Shore though.

:laugh: No, and it may be just as well, given the supposedly upcoming noise regulations...:whistle:

Honnestly, i do think that loud is reall noice :niceone: but I'm still a bit of a girly girl, somewhere deep down, and prefer a musical growl to actual bark...However, you should hear 007XY's :rolleyes: :shit:

[homer]

Enough of this levity and general chuckleheadeness. I have questions. :crazy:

So a piston reciprocates within the cylinder. The rings touch the sides and flatten off high spots during the first few hundred thousand cycles. At this stage the motor is referred to as tight. Fine.

Pistons do not simply reciprocate up and down. There are lateral forces transmitted by the conrod to the gudgeon and thence to the sides of the pistons. The conrod converts a turning force from the crankshaft into a vertical force but there is some sideways pressure.

So logically, since the lateral forces only go to each side, the bore should become slightly oval. Right?

But rings are floating. How can they turn and flex and move yet form a seal if the shape they are forming changes every 90 degrees? :dodge:



This is all true
its called the thrust side
which is when the spark occurs it forces the piston harder to the front side of the cylinder
when it comes back up its with less force

[homer]

You talk to your momma with that mouth? :spanking:
And there was I, trying to learn and take part in a serious bike thread...That''ll learn me! <_<

Now, back on topic...does the "bedding in" time vary from bike to bike? For example: would a Vtwin take longer than a normal in line four?

Reason I ask: still doing research for potencial next bike.

i dont think it would take longer at all but this would depend on the woman and the time required and i guess the bed could be a problem
but i say no moslty just depends on the woman :whistle: