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Breaking in an Engine
- Thread starter akbeemer
- Start date
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- Tags
- engine breakin
pglaves
#13338
I found the noted difference in ring end-gap interesting. The gap gets bigger when the ring wears. 
Also, he didn't mention ring sealing against the lands of the ring grooves. Good sealing here usually requires the buildup of a bit of varnish.
But he did make a point and it is that any differences are not yet significant at 1,000 miles. But failed, of course, to determine what they might turn out to be at 20K or 50K miles.
Also, he didn't mention ring sealing against the lands of the ring grooves. Good sealing here usually requires the buildup of a bit of varnish.But he did make a point and it is that any differences are not yet significant at 1,000 miles. But failed, of course, to determine what they might turn out to be at 20K or 50K miles.
I’d always followed manufactures recommendations till I got my 1600gt, it was a demo bike with 1500 miles on it when I got it. Pretty sure it was ridden like it was “stolen” during its demo time, I know I did on demo ride!! In the next 25,000 miles it had zero oil usage
My 15 RT wasn’t babied and at 12,000 miles no oil usage so far
One caveat both bikes had 600 and 1500 mile oil changes and changes every 4000 miles thereafter
Top tier synthetic oil only
Jim
My 15 RT wasn’t babied and at 12,000 miles no oil usage so far
One caveat both bikes had 600 and 1500 mile oil changes and changes every 4000 miles thereafter
Top tier synthetic oil only
Jim
I think a combination of the two extremes might also work. Upon first start, I hold RPM at around 3000 for 45-60 seconds, then without stopping the engine, immediately go for my first ride for about 20 miles, avoiding idling as much as I can. For the duration of the break-in period, I try to only go to 75% of normal RPM before shifting, getting good acceleration and deceleration phases during the rides. I feel the first minute is important as there's little oil to "float" the metal rings off of the cylinder wall, thus promoting good wear on the rings before the oil starts to splash and heat up on the cylinder walls.
Then again, on my /7, I decided to break it in the same way I would ride it. I changed rings within the first year or so of ownership (I'm 2nd owner)...felt I was using too much oil. Lasted probably 80K miles with reasonable oil usage...changed things when I freshened the top end at 100K miles.
Then again, on my /7, I decided to break it in the same way I would ride it. I changed rings within the first year or so of ownership (I'm 2nd owner)...felt I was using too much oil. Lasted probably 80K miles with reasonable oil usage...changed things when I freshened the top end at 100K miles.
stooie
Member
Yes and No
Ari makes several excellent points:
1. This is an extremely contentious topic.
2. Break in involves all engine metal sliding surfaces: gears, bearings, and cams as well as the probably most sensitive area - the piston ring / cylinder wall interface.
3. Advances in metallurgy, machining processes, and lubricants have vastly reduced the criticality of the break-in procedure.
Some things he didn't touch upon:
1. All though he and his troops did a sincere job of inspecting before and after, I think they missed some critical parameters. The microscopic surface finish of the rings and cylinder walls and how they change with time is what the break-in process is all about. Without quantitatively measuring this I think they (and we) are just waving our hands and talking loudly.
2. Ari described looking at the oil at the oil change intervals. Um... how 'bout sending it to the lab and getting some numbers?
3. For most modern cars and bikes, the engine is probably 99% broken in by the time you get it home from the dealership. There's so little wearing in to do that it happens in minutes, not hundreds of miles. This is why most of us don't experience any measurable oil consumption on a new engine. My 18 RT oil level didn't drop any perceptible distance (much less than 1 mm) in its first 600 miles. I expect that experience is pretty typical.
4. "Ride it like you stole it" is a myth in terms of stressing the engine during street riding. Running-in a light aircraft reciprocating engine involves operating full throttle for 5 - 10 minutes at a time broken by lower-power cool down periods. Even the most squidly of bike riders would be hard pressed to maintain full throttle for more than ten seconds at a time before arriving at arrest me/suicidal speeds. At a race track one is able to hold wide open throttle for 50 - 90 per cent of the time; on the road, not even close.
All of this leads me to advise taking the Bobby McFerrin approach to breaking in a new engine: Don't worry; be happy.
Ari makes several excellent points:
1. This is an extremely contentious topic.
2. Break in involves all engine metal sliding surfaces: gears, bearings, and cams as well as the probably most sensitive area - the piston ring / cylinder wall interface.
3. Advances in metallurgy, machining processes, and lubricants have vastly reduced the criticality of the break-in procedure.
Some things he didn't touch upon:
1. All though he and his troops did a sincere job of inspecting before and after, I think they missed some critical parameters. The microscopic surface finish of the rings and cylinder walls and how they change with time is what the break-in process is all about. Without quantitatively measuring this I think they (and we) are just waving our hands and talking loudly.
2. Ari described looking at the oil at the oil change intervals. Um... how 'bout sending it to the lab and getting some numbers?
3. For most modern cars and bikes, the engine is probably 99% broken in by the time you get it home from the dealership. There's so little wearing in to do that it happens in minutes, not hundreds of miles. This is why most of us don't experience any measurable oil consumption on a new engine. My 18 RT oil level didn't drop any perceptible distance (much less than 1 mm) in its first 600 miles. I expect that experience is pretty typical.
4. "Ride it like you stole it" is a myth in terms of stressing the engine during street riding. Running-in a light aircraft reciprocating engine involves operating full throttle for 5 - 10 minutes at a time broken by lower-power cool down periods. Even the most squidly of bike riders would be hard pressed to maintain full throttle for more than ten seconds at a time before arriving at arrest me/suicidal speeds. At a race track one is able to hold wide open throttle for 50 - 90 per cent of the time; on the road, not even close.
All of this leads me to advise taking the Bobby McFerrin approach to breaking in a new engine: Don't worry; be happy.
Ditto.
greenwald
New member
Another thing not considered is variation in castings, finishing and assembly. I suspect many DOHC 1200’s left the factory with bores slightly out of round at operating temperature, causing variable oil consumption issues for at least some of those bikes, regardless of break-in procedure followed.
FWIW, one BMW R1200 cylinder is similar in size and design to a Suzuki DR650 cylinder, but DR’s are not known for break-in issues or oil consumption, so it’s at least possible to build a 4 valve 650cc nicasil-type cylinder correctly.
I’ve also read that some have had to ‘beat’ their R1200’s to get them to stop burning oil.
FWIW, one BMW R1200 cylinder is similar in size and design to a Suzuki DR650 cylinder, but DR’s are not known for break-in issues or oil consumption, so it’s at least possible to build a 4 valve 650cc nicasil-type cylinder correctly.
I’ve also read that some have had to ‘beat’ their R1200’s to get them to stop burning oil.
powwow
Member
I"m currently breaking in a new 2018 Honda CRF250 Rally. My plan in addition to the usual vary the RPM's, etc., is to run dino oil for the first 3000 miles, then switch to synthetic. I don't know specifically if that makes a difference in break in, but it makes me feel good so that's what I'm going to do.
Uh oh...I may have just started an oil thread.
Uh oh...I may have just started an oil thread.
pglaves
#13338
It should, but it won't.
Of course it won't. A sample size of two, and the barest minimum of mileage proves absolutely nothing. From a scientific research standpoint is is just an elaborate anecdote. But believers will stay believers because they want to be believers.
greenwald
New member
IMO, and I have rebuilt hundreds of different engines over the years, about 50% of the break in happens in the first few minutes, and 90% of the break in happens in the first hour of running. Also, if the engine is warmed up I do not believe flogging it a bit will hurt it at all, not more the flogging it after 5,000 miles. The worst is taking a cold, new engine and putting it to work without warming it up.
Considering the dealer will set up the bike and run it a few miles the worst is over by the time the owner picks it up. The first few minutes are more critical than the next few hours.
Considering the dealer will set up the bike and run it a few miles the worst is over by the time the owner picks it up. The first few minutes are more critical than the next few hours.
akbeemer
SURVIVOR
On the new bikes I have purchased in the past several years I have changed the oil and filter as soon as I rode it home. That has ranged from 20 to 125 miles. I figure any debris that is produced by break-in will be in the oil very soon. I can say with scientific certainty that this practice has been successful in making me feel better. If I ever buy another new bike I should send that first oil to a lab for analysis.
ncpbmw1953
Member
I haven't rebuilt a single engine, did remove the head and did a valve job on an old Saab once though! Adhering to what seemed reasonable to me ever since I bought my '16 RT new I always start the bike when cold and just let it idle for about 30 to 60 seconds, then head down my flat quiet street and keep RPMs not more than about 2200, just ambling along at a slow pace. Once I see the coolant temp start increasing I will start adding a little more revs. At 37K miles now no oil is used between changes, which I do at 4-5K miles using full synthetic oil. I'm sure this ritual is hardly necessary but I like to do nice things for her then she lets me ride her real hard
dieselyoda
Active member
Same boat, rebuilt lots of engines, almost all big diesels, 700 cui and larger. Break-in occurs right away or not at all.
dlong
New member
I had the dealer do a dyno break-in, followed immediately by an oil and filter change. A printout of the HP and torque curves was provided, confirming that the motor was up to factory specs. I realize that not everyone may see the value, with a cost of about $300, but I did enjoy riding the bike hard from the get-go.
On bikes, rarely have the opportunity as we are second owners on all but one of our bikes.
Have one 1100R that must have been babied as it always has been oil needy, but not enough to fret over, just deal with it.
Our /6 until I did a top end refresh also used a bit more than I cared for.
When we do, its the manual recommend methods, no same rpm droning and no serious high revving early.
Have rebuilt VW and American V-8's among other smaller utility engines, including motorcycles..worry at start up if I lubed where I needed to lube during assembly, but after run in and many miles and oil changes later, overall satisfied it broke in well and I am overthinking the whole process.
My chuckle is how many generators, welders, water pumps, and other high dollar utility engines running at pretty much one speed their whole life from that original start up one does is not a concern to many.
Have one 1100R that must have been babied as it always has been oil needy, but not enough to fret over, just deal with it.
Our /6 until I did a top end refresh also used a bit more than I cared for.
When we do, its the manual recommend methods, no same rpm droning and no serious high revving early.
Have rebuilt VW and American V-8's among other smaller utility engines, including motorcycles..worry at start up if I lubed where I needed to lube during assembly, but after run in and many miles and oil changes later, overall satisfied it broke in well and I am overthinking the whole process.
My chuckle is how many generators, welders, water pumps, and other high dollar utility engines running at pretty much one speed their whole life from that original start up one does is not a concern to many.
happy wanderer
Day Dreaming ...
My '00 RT is a bit of a slurper. Has been since I rode it home from Raleigh NC. The previous owner only rode it under 10K miles in 10 years and I am quite sure he toddled along at 60mph or less in 5th gear most of the time. So the rings never broke in properly.
I've redone the top end on both my airheads in the last two seasons. Both times I followed a similar process. At first startup I revved to 3K RPM with basic carb rebuild settings for about 2 or three minutes. Then I jump into my gear and go for a ride that involves a lot of speeding up and slowing down to no more than 5 or 6K for a good hour or two. By now the job is probably done but I continue to stay under 6K RPM for a hundred kms or so and then I just ride the bike like I stole it as per usual.
In both cases about a half a liter disappears and then it stays there in the middle range of the dipstick as airheads normally do. Filling them to the top mark of the dipstick is futile; just like the oilheads. When filled to the full top mark they come down to the middle anyway. A slurper will continue on it's way down while the well broken in engine will stay there and not use much or any more oil unless you ride the heck out of it ALL the time.
I've redone the top end on both my airheads in the last two seasons. Both times I followed a similar process. At first startup I revved to 3K RPM with basic carb rebuild settings for about 2 or three minutes. Then I jump into my gear and go for a ride that involves a lot of speeding up and slowing down to no more than 5 or 6K for a good hour or two. By now the job is probably done but I continue to stay under 6K RPM for a hundred kms or so and then I just ride the bike like I stole it as per usual.
In both cases about a half a liter disappears and then it stays there in the middle range of the dipstick as airheads normally do. Filling them to the top mark of the dipstick is futile; just like the oilheads. When filled to the full top mark they come down to the middle anyway. A slurper will continue on it's way down while the well broken in engine will stay there and not use much or any more oil unless you ride the heck out of it ALL the time.
