Jump to content
Dodogree

Engine run in and pillion

Recommended Posts

Dodogree

When you are running the engine in on a new bike, when is the earliest you can have a pillion?

I'm at 103 miles at the moment, but I don't think I can hold the Mrs much longer, she's too excited to go for a ride... :hyper:

 

  • Like 1
  • Haha 1

Share this post


Link to post
embee

In reality it's about the best thing you can do. The most difficult thing on a bike with relatively high power/weight ratio is getting enough load on the engine without revving it too much. With cars it's fairly easy.

The principle behind a good break-in is to progressively increase engine speed and load during the first 10-20hrs of running, the engine speed being the more important aspect (sliding speed of rings in bores is what generates the high local temperatures at the points where the metal to metal contacts occur while they wear to conform to each other). In a car you can apply plenty of load (throttle opening) at low and mid speeds for reasonable periods without exceeding speed limits etc, on a bike you're usually limited to a few seconds before speeds increase too much. Get a pillion on, find some hills and pull up them using progressively more throttle as miles increase. Keep the engine to mid speeds for the first couple of hundred miles/5hrs or so, then progressively increase the revs you use through the gears. By 500mls/20hrs you should ideally be using full throttle occasionally and letting it rev through to near max every now and then. This is essential to get the full bedding of rings/bores. The engine will perform and behave better over a longer service life if you can do it this way.

Don't leave the engine idling while warming up, it's not good for it. Start it, let it settle down for 30sec or a minute or so, then ride off gently until it's reached normal temp.

  • Like 1

Share this post


Link to post
Dodogree

That's great news embee, the Mrs will be very very happy!

The thing is that I have the DCT version, so no real control over revving.

I could go manual, but don't want to, I'm enjoying the DCT so much.

I assume leaving it in D would essentially be the same thing.

The commute to/from my and my Mrs work is 5 miles and the max speed limit is 50.

If I understand you correctly, these speeds are ideal for the first hundred miles.

Share this post


Link to post
trisaki

Wouldn't use "D" gets into top too soon use S for around town  and D for faster roads 

  • Like 1

Share this post


Link to post
elbee

OK, I'm calling "Emporer's new clothes" here. Proposition: running in is a waste of time.

 

I ran my bike in properly in August (96 mpg, 60-65mph on a few short M'way bits) but thinking about it, is there any empirical evidence? What difference at 40K or 80K miles can be detected in an engine that was run in "properly" compared to one that was just ridden "normally" for the first 300 or so?

 

I average 87 mpg. All my bikes are always treated gently after starting when cold.  Recent thread - apparently you can run a bike with no head gasket without doing any harm.

 

I'm concluding running in is not required on a modern engine.

  • Like 1
  • Thanks 1

Share this post


Link to post
embee
8 minutes ago, elbee said:

..... Proposition: running in is a waste of time.

 

...., is there any empirical evidence? ......

Plenty of knowledge in the engine design/manufacturing industry.

This debate is done to death on all bike/car forums. The engine industry has established "ideal" break-in procedure strategies for very sound engineering reasons and the effects are well recorded and understood, more or less along the lines I suggested earlier and have described in previous threads, but it's your engine and you can do what you want with it.

  • Like 1
  • Thanks 1

Share this post


Link to post
Andy m

Just ride it and don't go mad. Pillion as soon as you like unless you are doing the Hardknott.

 

Don't forget you are bedding brakes and settling a gearbox too. The piston rings debate on REOC is only second to the oil thread in is resemblance to a cat fight in a certain Soho establishment. Don't feel the need to get involved, most bikes survive regardless. 

 

Andy

  • Like 3

Share this post


Link to post
embee

There isn't a lot of debate amongst folk who design, develop and manufacture piston rings and cylinder bores. They're more or less of a common mind.

 

It'd be worth getting used to using the manual mode too, it'll let you have the engine running exactly how you want regarding load and speed. I wouldn't lose too much sleep over that though.

  • Like 1

Share this post


Link to post
gonzo

Let it spin freely, dont let it labour, it should be fine, !!

Share this post


Link to post
Gerrymac

Ride it like you own it.

  • Haha 1

Share this post


Link to post
DelBoy
1 hour ago, Gerrymac said:

Ride it like you own it.

Exactly....

 

 

Modern bikes are so well engineered that I would not  worry too much about "running in" as long as you do not thrash the life out of it or conversely put it under too much load you should be ok.

 

In fact "running in" too carefully can glaze the bores,

 

Just ride it normally and listen/feel what the engine wants, let it spin but don't redline it everywhere.

It is quite a tourqey engine, so find the sweet spot and keep it there...

 

 

Share this post


Link to post
elbee

With everyone able to report their fuel consumption so easily these days, it seems my normal riding (87mpg) is probably more sedate than most people's running in. Not much chance of me thrashing it; on my Er6 I reckon I used full throttle/red line around four times a year :baby:

Share this post


Link to post
embee

As Del says, being too gentle or sedate isn't the best way to do it. Use it progressively harder through the break-in period, around 20hrs road use or 5-600mls is ideal. It's designed to operate up to max power, work up to that condition.

Share this post


Link to post
GerJ

Better only use S for running in, especially with a pillion. And if you need more revs than DCT is inclined to give you, there is always manual mode.

Share this post


Link to post
Graham NZ

Riding your bike 'normally' should be fine for 'running in'.  Just keep the engine from lugging and avoid long periods at idle and sustained high revs, say more that 4k.  Change the oil properly and at the recommended distances.  Some manufacturers put a different oil in at the factory from the one which is specified at the first change and beyond.  Keep checking for oil and coolant leaks until you are confident that all is well.

Share this post


Link to post
SteveThackery
On 12/01/2018 at 19:39, embee said:

There isn't a lot of debate amongst folk who design, develop and manufacture piston rings and cylinder bores. They're more or less of a common mind.

 

I'd like to understand this better, because in the motorsport industry "running in" is extremely brief compared with the norms for road vehicles.

 

What is different?

Share this post


Link to post
Spindizzy

Speaking as someone that has dealt with the effects of poorly 'run in' aero engines and its causes, just ride it normally. 

 

Don't be too gentle, keep the engine working. What you want is to maintain pressure on the rings. Gentle throttle at a constant speed I would avoid.

 

I will try to get some data from one of our test cell runs to show what happens to an engine that is mollycoddled versus one thats been given some beans.

 

As for Pillion, just do it. The extra mass will load the engine nicely

Edited by Spindizzy
  • Like 1

Share this post


Link to post
Trumpet

Being too gentle is the worst thing you can do. Use it normally, but don't lug it. Honda tend to bed in their engines before sale, so its a bit of a non issue. Most other manufacturers do as well. Triumph, on the other hand never used to, from personal experience.

Edited by Trumpet

Share this post


Link to post
Trumpet
47 minutes ago, Spindizzy said:

Speaking as someone that has dealt with the effects of poorly 'run in' aero engines and its causes, just ride it normally. 

Poor oil consumption ?

 

I had the priviledge of running in an IO-360-C1C Aero engine, and the real buttock clencher at the end was the full power run at near sea level. I could smell the hot paint in the cockpit baking on the Engine .. I was just off the coast, and I can't swim ..

Quote

 

 

Edited by Trumpet

Share this post


Link to post
Spindizzy
1 minute ago, Trumpet said:

Poor oil consumption ?

 

I had the priviledge of running in an IO-360-C1C and the real buttock clencher at the end was the full power run at near sea level. I could smell the paint baking on the Engine .. I was just off the coast, and I can't swim ..

 

Yep, drank oil like it ran on the stuff. Polished bores, poor compression. Its one of the reasons we set up our own test cell so we can pre-run in at full bore on a load. Too many well meaning pilots unable to grasp the concept of high power rich running in, or resented the fuel burn. Then its arguments about warranty etc.

 

Non ashless dispersant oils for run in until oil usage stabilises then back to AD oil.

Share this post


Link to post
Trumpet

Of couse its far easier to run in a Motorcycle Engine !.  No gears on a lycoming. Same principle though. Varying the Engine load to avoid glazing of the barrels.

Share this post


Link to post
Spindizzy

Modern Hondas its about as necessary as it was running in my Volvo. Just drive it. People far smarter than us designed it, developed it and built it with appropriate pre installation performance checks. However we do love to feel we have in some way contributed to the faultless engine that would have been fine almost no matter what we did.

 

Excluding aero engines, thats 1940's technology.

Share this post


Link to post
Foxy

I know running in has been covered to death but in the last 6 months we have purchased a new Mazda car and new Honda and BMW motorcycles, at no point did anyone ever mention a "run in" procedure. 

 

Forget about it, it seems Mazda, BMW  and Honda have.

  • Haha 1

Share this post


Link to post
embee

See, what do I know? Always happens.

  • Haha 1

Share this post


Link to post
embee
3 hours ago, SteveThackery said:

 

I'd like to understand this better, because in the motorsport industry "running in" is extremely brief compared with the norms for road vehicles.

 

What is different?

Not that anyone is interested, but just for you Steve ...... ;)

 

Have a look through this for example www.digitalmetrology.com/Papers/CylinderBoreNoBkgd.pdf

The idea of the manufacture is to achieve a plateau honed surface which will quickly wear down the peak asperities during the break-in, typically 10-20hrs run-time, and reach the "kernel" of the surface. This then gives the optimum oil retention volume and longest durability with normal wear rates. This phase can be usefully used to wear the ring periphery to conform to any "waviness" which might be present. This will ensure the optimum oil film thickness all round the ring, and to some extent helps reduce blowby.

This is a different source plot but gives the idea

 

DescribingASurface.jpg

 

A production car engine will need to comply with emission regs for typically 100k miles (certification standards) so the long term control of oil cons and blowby is important (catalyst deterioration). Rings are designed to retain acceptable wall pressure by starting off with appropriate tension ("tangential loads" or "tan load") such that as it wears and relaxes it retains control of oil/gas sealing over that service lifetime, maybe 10yrs/150k miles typically. They need to be robust enough to survive this, and consequently take a certain time to complete the initial bedding to get down to the bore surface kernel.

I don't have personal experience of racing engines, but I've worked with folk who have (from the company next door in fact). Everything is designed for lightness not durability. Bore surface finishing can be more time consuming, multi-stage honing, rings are generally much thinner and lighter and ring bedding will take place much more rapidly due to lower contact areas. The engines get oil changes every couple of hours typically (other than endurance which might be 24hrs but even then oil is typically added at a fair rate so is renewed in effect). They don't have to worry about emissions, exhaust catalysts etc, nor particularly oil consumption and blowby in quite the same way as a production engine.

The one thing in common is the need to avoid wherever possible any scuffing of rings and bores, where due to the initial contact on the asperities (high points in the roughness) and the sliding speed (which is why engine speed is the critical aspect rather than load) very high friction at the point contacts can generate enough heat locally to result in break-down of the oil film and then micro-welding and tearing of material. This more or less permanently damages the bore/ring interface. While minor scuffs will "heal" or polish over, it means the underlying plateau hone surface is lost locally and oil consumption etc is likely to be worse than ideal to a greater or lesser extent.

The addition of load to the engine as the bedding proceeds is beneficial, gas pressure from combustion gets behind the top 2 rings and helps force them out onto the bore, aiding the wear rate as the contact area increases. Not applying this extra gas loading can sometimes result in the wear effectively halting and the surfaces polishing instead, giving glazing. This is where the label "Don't baby your engine" sometimes attached to reconditioned light aero engines comes from. They usually get a somewhat extended sign-off test so the initial phase is done, it just need the final phase which asks for load to be applied.

One vaguely interesting thing is that the max piston sliding speeds for a 4-valve engine don't vary all that much regardless of type. A nominal 20m/sec is typical at max power, modern direct injection etc can raise that to maybe 23m/sec or suchlike, but it's a similar ballpark. It's down to gas speeds and speed of sound. The NC piston speed at max power is unusually low because it isn't a typical 4-valve design done for power, but that's another discussion.

Edited by embee
  • Like 1
  • Thanks 3

Share this post


Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×