Running in what do you advise ?????????

[Ian]

I've finally got a Skorpion up and running .
But it needs running in because it's had a new piston and a re-bore.
I always thought running in was gentle / mild riding for 500 to 1000 miles .

Until I found this :

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

Now I'm undecided ?

[themoudie]

Aye xbrmz,

We've had at least one debate about this on the site with many views expressed. Try using 'Search' facility on site menu bar above to see if you have luck finding the threads.

If no luck we'll just have to have another shot at it!

Regards, Bill

[steveD]

Having read the chaps information I am of the opinion that he has a very good valued argument. What he doesn't really explain is the necessity to get the engine up to normal running temperature before 'gunning it' as he says.
The engine is built of so many different metal of differing co-efficients of expansion, the main one being the piston which we all know is a mainly aluminium alloy which expands quicker than it's surrounding environment. The different metals will also expand in an un-uniform way as they are of differing sections as well, especially a gussetted piston.
Once all of the component parts are up to temperature the clearances designed into the engine will be at their optimum, if anything is going to tighten up then it has been machined incorrectly in the first place.
I used to be a toolmaker and regularly used to rebore my own barrels to suit a piston and spent a lot of time getting a nicely honed bore at the correct clearance (used to use the equation of 1 thou per inch of bore if my memory reminds me)
...but in them days I used the old fashioned way of running in!
I am of the personal opinion that providing the engine is up to working temperature then I would do as he says.


......but then that's me!


SteveD

[MrFluffy]

I used to be a toolmaker and regularly used to rebore my own barrels to suit a piston and spent a lot of time getting a nicely honed bore at the correct clearance

Hi steve, Id love to have a pop at doing this, Ive got a arno universal miller with a 40int head, and a micrometer head to suit, so getting the hole the right size should be do-able, but what did you use for a hone? Ive been told a brake cylinder hone is no good as it doesnt true up the cylinder properly, and needs a rigid hone to do the job properly. I dont have a rigid hone and theres nobody near here that does that sort of work, is it possible to make your own rigid honer do you reckon?

On the running in (so not to divert the thread too much), Ive heard a lot of people saying run in motors hard, and if its a two stroke I learnt a initial run-in proceedure from someone who knew his stuff. He used to start the motor up, and blip the throttle bringing the revs up and down quickly for a minute or so, then shut off and let it all cool. Repeat for 3 or 4 cycles all the time listening to the motor as it started to free, then he used to hand the bike to the owner and tell them to run it hard once he was confident it could take it. This was usually a motocrosser or some other high performance two stroke and he never seemed to have any bore related problems afterwards.

[Andy M]

The guy is right, but forgets a whole stack variations.

1. He's talking modern watercooled engines with tight tolerances and good bearings/oil flows. Try this on a Bullet and it'll sieze, the machining marks are massive compared to a Jap sports bike. The effect on a Yamaha/MZ engine will be something in between.

2. He totally forgets about any other component, his only interest is in the rings. A new bike has a new gearbox, new chain and sprockets etc. Not a concern if you only run in a rebore, but "an extra 30 hp" is no use if the gearbox output shaft breaks.

Look at all the other caveats. Use non-synthetic oil, change it after 20 miles etc. etc. He's had failures. Take your rebuilt engine and ride it gently with a slight leak on the head gasket. It'll run rough and you'll have it to fix. Take it to a dyno and rev the nuts off it......

My advice would be to ride it normally, avoid short trips, motorways and over heating and you'll get something in between.

Andy

[bullet350]

this man knows what he's talking about. i've heard a similar argument from many different sources. they all talk of taking the engine up and down the revs, but not right to the redline. don't stress the engine but let it spin.

this theory is all well and good but i think the thing that proved it for me is my mates 883r sportster. he stuck to harleys aincent running in ritual (no riding during the week of a solstice, or under a full moon) for a bit then decided to repeatidly flog the nuts off it.
he has an 883r that can pull 115mph, and does quite often. if you have a go on an 883 thats been owned by your average harley rider (you know the type) it probably wont pass 85mph. Seriously!
his bike currently has 55'000 miles on it and the motor sounds 'sweeter' than almost every other harley.

also after reboring the 350 bullet i rode it gently for a mile or so then treated it as usual. i'm certain its faster to 50mph than most 500's. although that was only sealing the rings.
however the bullet is a completely different kettle of fish on a new engine as the tollerances are measured by the inch.

lets face it, on a modern sports bike that revs to 14'000rpm running in is just for the rings. to allow 14'000rpm everything has to be very accurately made, if it needed running in then it'd never reach the redline, ever.

the jap singles are not made as accurately because there is no need, it'll all go a bit silent at 9'000rpm regardless.

i think this method of running in would need to be 'softened-up' for the bikes we all have but i think its spot on for a sports bike.

350bullet

[Steve H]

I was tempted to follow his advice with the SRX engine I rebuilt. In the end I didnt have the time to mess about so just started using it for work and worked it progressively harder as time went on. It was being thrashed quite hard after 200 miles.
Unfortunately an air leak made it run weak and hence hot, and it eventually seized on my way back from Holland.
The problem is pistons arent cheap (especially forged items) and so I can understand any reluctance to try this out.

[guest27]

You utter barsteward.  I was supposed to be rebuilding a kitchen cupboard and I have spent the couple of hours or more reading his meanderings.  Seems to swing between engineering and selling the idea of thinking on the right side of the brain.  Both I am interested in so double Grrrrrrrrr

As to his thoughts, not being an engineer I have to agree with most if not all of them.  Running in a bearing that has not been made properly will not make it a better bearing etc.  Was advised by a number of people who should know, in the past, to let the engine rev, dont over load it - lugging the engine puts loads of torque stresses on components etc (I think) buzzing it does not.  (Reccomendations from amongst others Stan Stephens, Kenny Irons and Mez of Mez Porting)

I am not sure his explanation as to why his smaller ports work better totally holds up.  I have a friend with a PhD in fluid dynamics maybe I will pass them on to him.  However as a canooins I have to say what he is doing looks right to me - cutting out the areas of the river where the eddies form, so increasing the total velocity of the charge and less variation in that velocity - less variation less waste.  What he is doing in the inlet port seems to be similar to Micron's serpent pipes, get rid of the inside of the bend - it is where the eddies form.  It may be that he couold get even better results with a larger valve area, but D shaped or extended oval ports, mind that is one of the things that 4 valvers have over 2 valvers - less difference between the inner radius and outer radius of the tube.

I guess where the idea wins out is on the track etc, and he seems to be doing pretty good.

Mind I did have a RD350LC that had been run in sooooo well - the guy I got it from probably never took it into the power for the 3500 miles he had it for, it was far and away the best engine of the LC's in the bike club of the time, out performing even the supposedly 'tuned' ones.  Ditto my RD500, the first owner would not take it above 5000 until the temp needle was above the notch (on the Yam gauge).  Met a couple of other guys with bikes they thrashed from the off - convinced me to stick to the warm it up properly approach.  Mind the first owner may have thrashed it from the off, once it was warm, for all I know.  His Sunday riding buddies included people like the aformentioned K Irons.

Having pulled the Triumph lump from the Triton apart many times, I think alot of what he says about the quality of bearing surfaces etc are as appropriate to that as to a modern bike.

R

[Ian]

I think I'll just ride a little bit gentler than usual for a couple of hundred miles .
I'll try to keep it away from the red line and not let it labour then treat it to early oil changes.

After all it's only the piston and bore that needs running in ,not the whole engine.
Come to think about it I've never run any engine in.

Rog ,
Don't worry about the kitchen cupboard It will still be there tomorrow.......

Tomorrow never comes though

[guest27]

Ahh the kitchen cupboard will be there tomorrow (today) but the Boss and the boys were home last night and I wanted it clared up.

Have been back to the Motoman stuff, interesting - and his reccomendations are somewhat different from my first thoughts - I was told to build it up over the first couple of hundred miles, re reqading it his suggestion seems to be a version of the 80/20 rule, in that 80% of the work is done in 20% of the time and then the last 20% of the work takes 80% of the time.  Also identifying that the first 20 miles (30 to 50 mins) are critical.  The time extends if you have coarser honing and older cylinder liners, but it seems to work as a process for Harleys and as far as I know they are pretty agricultural (ooops).

What was more interesting was cruising the net reading other discussions / articles about his process, either for or against it.  Seems most people who are against it are worse at reading than I am.  The number of people who claim his process is for a poarticular type of engine (he admits himself that he has used it exclusivly on Jap 4/4s) whilst other people have used it and sent their reports on anything from harleys to Aprillia V twins etc.  Sites claim it is a process for aircooled bikes only, or 2-strokes only.  That he has never worked on a bike himself etc etc etc.  Was quite fun.

He wrote quite a long reply on one of the Kwak discussion pages - they had been having an informed discussion rather than the usual - "Honda say do it this way" etc.  Admits himself that you can be more 'mellow' on a more heavily honed barrel.

Most common misreading however seems to be the assumption that he says, rev the nuts off it from cold, from the start, when he quite clearly does not.  Next biggest argument is that it will produce a shorter lived engine (with no evidence either way) however  he does look at the causes for engine wear, excluding catastrophic failure of a component, in the main this comes down to the lubrication (oil and surface) not doing its job as well as it might and how the acidic by products from blow by a significant feature in this - something that is reduced by getting them rings really well bedded in.

R

[Ian]

First ride out consisted of a few minuets warm up then 15 mins @ 30 mph stop start traffic followed by 50 mph for 10 mins a stop for a fag and then the same back .

All seamed well and I rode it gentle

I can't see me continuing to do that for 200 miles ,even on a short run I was getting a twitchy right hand .
 

[themoudie]

Aye xbrmz,

When you got home was the time to drop the oil and filter, whilst hot. Then replace with fresh oil and new filter. I'd have said stop, start, 30mph wasn't a good idea. But what is done is done. You maybe horrified if you get the grey sparkly stuff out of the sump now! However, fresh oil/filter, some more working through the gears after warming through and minimal choke should see it OK, with another oil/filter change at 200 miles.

You'll feel when it starts to slacken off and just give it a bit more spin on the throttle.

All the best, Bill

[Ian]

Hi Bill ,

" I'd have said stop, start, 30mph wasn't a good idea. But what is done is done."

You don't get much of a choice around here ,either keep up with the traffic or it will run over you !
30 was a guess it was probably nearer 20 / 25 mph.

I will take your advice on changing the oil before the next run .

Thanks
Ian

[guest27]

Hi There
Dont think it was the 30 that was the question - the stop start. But again running into someone just because you would prefer not to stop does not look good on the insurance claim.

R

[themoudie]

Aye Ian,

Not meant nasty. As Rog says, it isn't the speed, more the stop-start.

I also know that I'm spoilt for variety of roads and scenery around here.

Hopefully it''ll all bed in nice for you.

Regards, Bill