running new piston rings and bores in ?
 

how should i run the new piston rings and bores in ? 6k for a million years or just work my way up the rev range like 1k at a time every 10 miles or something like that

Re: running new piston rings and bores in ?
 

I think the key is, not to thrash the knackers off it straight away.

And it's about letting the metals get hot then cool, hot then cool.
They wear/bed in nice that way....

Re: running new piston rings and bores in ?
 

Rest of engine is already bedded in. Avoid low speed/high load situations.

Go and ride gently for 10 miles until at full temp, then with fairly light throttle accelerate to high rpm smoothly in first then coast back down, ride gently a bit more, do same in second etc. When you get up to third you'll need to add throttle in order to smoothly accelerate, this is what breaks it in. Keep this up for 50 miles then change oil and you are done breaking it in.

Do not go flat out, do not let it lug and bitch at low rpm, after every run up to rpm let it coast back down on engine braking to cool off, don't keep constant speed/throttle for a long time keep varying it.

Re: running new piston rings and bores in ?
 

Agree with Chris---------important thing is the oil change,no later than 100miles and it doesnt do any harm to change it again at 500 max.
Even with a brand new engine I change it at 100 again at 200 then 500 building up to max revs after which I consider it well and truely run in. I've never had a problem doing this,not with oil consumption or a slow engine.
I am aware what the book says just my way of doing it.

Re: running new piston rings and bores in ?
 

The most important parameter is sliding speed of the rings, i.e. RPM. Don't increase the max RPM you use too soon, gradually increase it as hrs/mls increase. Sliding speed is what can cause scuffing or micro-welding of rings and bores. EDIT - this is crucially important with bores honed at an outside machine shop, they tend to produce surfaces significantly rougher that manufacturers do. Err on the side of caution.

Engine load is a secondary parameter. It's not as sensitive to load as it is to speed (there's only high pressure on things for one out of the 4 strokes).

It needs to be a progressive process. The first 15mins is the most important. Keep RPM to typically no more than about 30-40% of max.

In engine development you'd consider a "full" break-in to take typically around 10hrs test bed run time in a light duty petrol engine, maybe a bit more on-road.

In broadest terms just gradually increase engine speed at light loads and add load at the lower speeds as you ride. Accelerate gently in low gear up to the target RPM, change up and make it pull a little harder then ease off the throttle as the RPM increases.

As time goes on gradually raise the RPM target and allow the higher load to be used for a little longer.

For the first hour or so, the ideal thing (dull as it might be) is to ride round town (as long as you can keep moving more or less, not sitting stationary).

By 5hrs (typically 200mls) you should be using up to say 5-6k RPM briefly and up to around half throttle briefly.

By 10hrs/500mls use 8k and full throttle briefly.

After that it's ideal to try to get some real load on it for short spells, accelerating up steep hills ideally with a pillion works a treat, I use Fish Hill down at Broadway.

Change the oil as frequently as you like, personally I don't overdo this, we'd never change oil during a test bed break-in, filters are pretty good these days.

You can't do a proper break-in in half an hour, whatever others may say.

Re: running new piston rings and bores in ?
 

ok so should i change oil filter after the bed in process ?

and when should i change the oil 100miles - 200 miles ?

Re: running new piston rings and bores in ?
 

Well the others have given recommendations, personally I'd say do an oil change at maybe 200mls then oil+filter at 500mls, after all it's relatively small oncost compared to what you've already spent, and it can't do any harm.

One other thing, there's no advantage in doing a break-in in short bursts, you can do it all in one go if you feel like riding all day. A 10hr test-bed break-in would be done in one go usually.

Re: running new piston rings and bores in ?
 

ok cool just wondered because 10 hours usually amounts to more than 100miles ..... got a lot of riding to do tomorrow then :D

Re: running new piston rings and bores in ?
 

There is conflicting views on how to do it. Best to air on the side of caution and do the usual.

I after reading some bike engine mechanic blog, i tried a different technique. I cant remember exactly how, but i did none of the staying at xxxx revs for the first xxx etc.
I Just rode it through all the rev range from the start, i changed the first batch of mineral oil very very early, then the second batch at the standard recommended milage.

Compression was perfect, and it didn't burn any oil after id finished, cant say if it was any better doing the way i did, but thought id try something different.

Re: running new piston rings and bores in ?
 

^ i have also heard that as well, i think it was some where on hear that it was been talked about

Re: running new piston rings and bores in ?
 

There were photos off different pistons from engines run in differently. I think that conviced me to give it ago, was 2 years ago now, i forget the details. :-)

Re: running new piston rings and bores in ?
 

Well, not blowing trumpets or anything but I've worked in Engine design and development for 30+ years, including piston/bore interface development which means working with piston/ring manufacturers to specify materials, profiles, clearances, surface finishes etc, even modifying the block structure and cooling if required, and what I described was in essence how it would be done according to industry knowledge. That's all.

Yes, 10hrs is more than 100mls, maybe read it again. On the road during a sensible break-in you're likely to average somewhere round 25mph early on and maybe only around 40mph later. 500mls will amount to around 15hrs running total, which is fine.

In the end it's your engine and do what you will.

Re: running new piston rings and bores in ?
 

I agree, and i would advise everyone to take your advise.

I was just putting it out there :-)

Re: running new piston rings and bores in ?
 

We have always bedded our racebikes in on the dyno, running the bike upto temperature circa 80oc and then letting the bike cool down. Usually repeating this process around 5-6 times and each time gradually increasing the load on the engine.

The bike then goes to the test day, run upto temperature fully before going on track and taking the first session steady but using full revs. IE not stressing the engine, just letting it rev out freely.

Then go off and race. Have had no issues with rings or bores using this method.

We often find the biggest killer on the SV is when people run no thermostat and a larger radiator and dont keep an eye on the running temperature and then let the bike run too cold.

This is on the SV's aswell as any other bike.

We only use Fully synth oil in all the bikes now and the oil will get changed along with the filter after the first test day.

Re: running new piston rings and bores in ?
 

ok cheers for the info, kept it below 4k for the wee ride today until it decided to empty its coolant all over me ... o ring on order...

reminds me i need to get my vapor reading temp again i left it for 15min on tick over before i rode it so should have been up to temp (rad felt like it was)

Re: running new piston rings and bores in ?
 

Ride it gently until the engine is fully warmed up, then ride it like you stole it! :o

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

I have never tried this method, BTW.

Re: running new piston rings and bores in ?
 

That sounds like a Shervin!! (Guy looks like him too)

Re: running new piston rings and bores in ?
 

oh look, free extra power available right off t'internet...

One question though, it was always said to use any old crap oil for running in and not good oil, then change it for good stuff after the first period (e.g. 600 miles) otherwise you'd always (?) get a smoky engine. Any real truth in that?

Re: running new piston rings and bores in ?
 

in a new modern bike motor, the oil is meant to be slightly different for the running in process. I don't know the exact truth in that

Re: running new piston rings and bores in ?
 

the rest of it i honestly know nothing about, but an oil filter is barely £10 so for what its worth just change it with every batch of oil. just my opinion fella.

Re: running new piston rings and bores in ?
 

Modern syth oils apparently lubricate so well that it will take a long time to bed the rings in. Thats why its said you should use standard mineral oil.

Just repeating what is said elsewhere on the internet though, no way of testing this myself.

I personally would change the filter after the bed in process, because this is the time the engine will experience the most wear in its lifetime.

Re: running new piston rings and bores in ?
 

In essence, no. Use the regular oil, 10W-40 semi synth bike oil (JASO-MA). Very basic oils tend not to have the anti-scuff properties (cheaper additive pack), and you still want to protect for that.

In simple terms fully synth isn't "slipperier" or anything, it has better stability and high temperature capability than "traditional" mineral oils, so it can offer better protection under extreme conditions and will offer a longer service life, that's it in a nutshell. By high temps I mean local surface temps between rings and bores, which can be 160C+, not bulk oil temp in the sump (more typically 100-130C).

There's plenty of tech reading on the 'net, but try this for quite readable and accurate stuff.