Running in engines
Discussion
My new 160 is about 6 weeks away now so I'm starting to think about things like running in engines.
Has anyone seen this before?
http://mototuneusa.com/break_in_secrets.htm
My experience with Lycoming aviation engines would seem to bear out the advice in this article. You don't need to rev engines too hard but you do need to make them work early on. The power difference was VERY noticeable for machines that weren't baby'ed through the first hours of their run in.
I don't know if aviation engines are different from automotive. Any opinions or experiences that confirm or contradict this?
Has anyone seen this before?
http://mototuneusa.com/break_in_secrets.htm
My experience with Lycoming aviation engines would seem to bear out the advice in this article. You don't need to rev engines too hard but you do need to make them work early on. The power difference was VERY noticeable for machines that weren't baby'ed through the first hours of their run in.
I don't know if aviation engines are different from automotive. Any opinions or experiences that confirm or contradict this?
My old gran used to say (yes she was a mouthy bint) "The faster you run them in, the faster they go." And I think this was advice given to her by a race engineer, so it probably makes sense.
This 'regime' method seems to work on high revving motorbike engines, so a high reving Honda might be the same. How does iVTEC effect this though?
This 'regime' method seems to work on high revving motorbike engines, so a high reving Honda might be the same. How does iVTEC effect this though?
There was a great article in one of the bike mags that compared a Blade which had come out of the crate and did the TT race - bog standard - and a reader's one who had run it in carefully. The first produced 127bhp; the carefully run in one 117bhp. Autocar also published acceleration stats on a number of their long-term cars over time. All of them improve significantly.
The reason why you have to thrash it out of the box is difficult to accept for people who remember the good old days. Machining standards are so much better and hence the tolerances are much tighter, that there simply aren't "rough edges" to smooth off, which used to be the case. Metallurgy and casting techniques have also improved, so the wear resistance and consistency of the metal is much, much better. Couple that with the quality of modern synthetic oils, which coat the surface more thoroughly, degrade less and bond much better with the metal, particularly over time, and you can get a modern engine with 20,000 miles or more on the clock that hasn't loosened up and may never do so fully.
Net is that you need to CAUSE a high wear rate in the early days of the engine before the wear surfaced become too polished (as opposed to "bedded in") to loosen the engine. This is why the bores in new engines have a light cross-hatched surfaced honed onto them. If they do become too polished, the oils can't bond properly and the engine will remain tight and seal badly. The initial high wear rate declines very quickly as the surfaces do polish, so the curious situation is that the period you have available to get the engine bedded in is very short. There is virtually no effect on longevity, and remember that internal friction is the enemy of power and torque.
Goes against the grain to old f@rts like me, but that's the engineering reason why you need to thrash them out of the box. Don't forget to change the oil and filters after 500-1,000 miles.
MC
>> Edited by coxm on Friday 15th April 16:16
>> Edited by coxm on Friday 15th April 16:17
The reason why you have to thrash it out of the box is difficult to accept for people who remember the good old days. Machining standards are so much better and hence the tolerances are much tighter, that there simply aren't "rough edges" to smooth off, which used to be the case. Metallurgy and casting techniques have also improved, so the wear resistance and consistency of the metal is much, much better. Couple that with the quality of modern synthetic oils, which coat the surface more thoroughly, degrade less and bond much better with the metal, particularly over time, and you can get a modern engine with 20,000 miles or more on the clock that hasn't loosened up and may never do so fully.
Net is that you need to CAUSE a high wear rate in the early days of the engine before the wear surfaced become too polished (as opposed to "bedded in") to loosen the engine. This is why the bores in new engines have a light cross-hatched surfaced honed onto them. If they do become too polished, the oils can't bond properly and the engine will remain tight and seal badly. The initial high wear rate declines very quickly as the surfaces do polish, so the curious situation is that the period you have available to get the engine bedded in is very short. There is virtually no effect on longevity, and remember that internal friction is the enemy of power and torque.
Goes against the grain to old f@rts like me, but that's the engineering reason why you need to thrash them out of the box. Don't forget to change the oil and filters after 500-1,000 miles.
MC
>> Edited by coxm on Friday 15th April 16:16
>> Edited by coxm on Friday 15th April 16:17
i read all that stuff some time ago, as did my boss, who'd just bought his T350.
he's a good engineer, and he stuck to the book, ie run in gently.
has anyone actually subscribed to that site and found out the 'secret'?
i'd like to believe it, but it goes completely against everything i was ever taught about engines in my younger days, and i'm struggling to get over my indoctrination.
have previously heard about the tests the bike mags did.
what i'd really like to see is someone who's done a breakdown with a reasonable number of engines from the same production line at the same time under the same conditions.
ie a controlled experiement. until i've got some real stats to look at....
are there any manufacturer's out there who actually recommend the procedure given by matey?
he's a good engineer, and he stuck to the book, ie run in gently.
has anyone actually subscribed to that site and found out the 'secret'?
i'd like to believe it, but it goes completely against everything i was ever taught about engines in my younger days, and i'm struggling to get over my indoctrination.
have previously heard about the tests the bike mags did.
what i'd really like to see is someone who's done a breakdown with a reasonable number of engines from the same production line at the same time under the same conditions.
ie a controlled experiement. until i've got some real stats to look at....
are there any manufacturer's out there who actually recommend the procedure given by matey?
Honda.
There is no difference with aero engines, this is about machining quality and metallurgy, not configuration or usage.
Its how our new supercharged one will be run in. Its how we manage our race engines, and is consistent with advice from people like Ricardo. Its what happens to Formula 1 engines (except the oil change).
I hadn't read the link before writing my diatribe above; I don't think that what matey is suggesting there is that controversial - certainly not in the bike world - these days. The points he makes aren't contentious: his focus on ring sealing is more important for bike engines than cars, since
a) they run fewer rings than in cars, where the longer period (which is the polishing issue I referred to) rather than the sealing issue becomes more relevant; and
b) the stroke is much shorter and piston speeds higher, so the ring is in contact for a shorter period so there is less time for the pressure to build.
The point on oils is spot on as well - as I alluded to with the point on oil efficiency.
What is not brought out in the link is that it is vital not to use constant load conditions, whatever the load level, running in. Different throttle positions, revs, gears and loads are important to prevent any pattern-related wear in the early stages. Its intrinsic in what he says, but not explicit.
I know it goes against the grain, but he's spot on. If you like, we can dyno Al's and mine new (although that alone will help yours significantly compared with the traditional proceedure) and then again after 1,500 miles and I'll bet mine is more powerful (relatively, before Bruce points out that I am cheating since I have a 300 coming!).
MC
>> Edited by coxm on Friday 15th April 16:20
There is no difference with aero engines, this is about machining quality and metallurgy, not configuration or usage.
Its how our new supercharged one will be run in. Its how we manage our race engines, and is consistent with advice from people like Ricardo. Its what happens to Formula 1 engines (except the oil change).
I hadn't read the link before writing my diatribe above; I don't think that what matey is suggesting there is that controversial - certainly not in the bike world - these days. The points he makes aren't contentious: his focus on ring sealing is more important for bike engines than cars, since
a) they run fewer rings than in cars, where the longer period (which is the polishing issue I referred to) rather than the sealing issue becomes more relevant; and
b) the stroke is much shorter and piston speeds higher, so the ring is in contact for a shorter period so there is less time for the pressure to build.
The point on oils is spot on as well - as I alluded to with the point on oil efficiency.
What is not brought out in the link is that it is vital not to use constant load conditions, whatever the load level, running in. Different throttle positions, revs, gears and loads are important to prevent any pattern-related wear in the early stages. Its intrinsic in what he says, but not explicit.
I know it goes against the grain, but he's spot on. If you like, we can dyno Al's and mine new (although that alone will help yours significantly compared with the traditional proceedure) and then again after 1,500 miles and I'll bet mine is more powerful (relatively, before Bruce points out that I am cheating since I have a 300 coming!).
MC
>> Edited by coxm on Friday 15th April 16:20
well, did a search last night with google on "running in" and "bed in", and it bore out pretty much everything you've said Meyrick - and as you say running at constant revs is a Very Bad Thing.
Apparently letting the engine run down ( engine braking ) is good, as this encourages oil up the sides of the pistons to sweep out debris, though it's not ideal to drop down through the gears.
do not labour the engine ( low revs, wide open throttle ).
only other thing that a lot of guys seem to say is not to use the full rev range initially ( limit to aout 75% ) with only an ocasional blip to the red line, and change the oil early ( at 500, and i can't imagine changing again at 1000 or 1500 would do any harm ) to clear all the microscopic bits of metal, and harmful chemicals produced during combustion, out of the system.
it seems that after the initial change you're ok to go use the full extent of the rev range.
all this garnered during a trawl of the net, so none of what i am saying is based on my own experience ( i've never had a new engine ), but it all seems to be based on sound reasoning.
makes sense to me anyway, so when i get mine that's how i'll go about it, unless anyone can convince me differently
Apparently letting the engine run down ( engine braking ) is good, as this encourages oil up the sides of the pistons to sweep out debris, though it's not ideal to drop down through the gears.
do not labour the engine ( low revs, wide open throttle ).
only other thing that a lot of guys seem to say is not to use the full rev range initially ( limit to aout 75% ) with only an ocasional blip to the red line, and change the oil early ( at 500, and i can't imagine changing again at 1000 or 1500 would do any harm ) to clear all the microscopic bits of metal, and harmful chemicals produced during combustion, out of the system.
it seems that after the initial change you're ok to go use the full extent of the rev range.
all this garnered during a trawl of the net, so none of what i am saying is based on my own experience ( i've never had a new engine ), but it all seems to be based on sound reasoning.
makes sense to me anyway, so when i get mine that's how i'll go about it, unless anyone can convince me differently
I had my engine on a Pulsar GTi-R rebuilt by a guy that used to make the engines for the BTC Cosworths etc. His instructions on running in where very precise.
First 200 miles
60% rev's max and never full throtle.
200-600 miles
75% rev max, full throttle possible further up the rev range.
Up to this point ran on very basic (but good) oil.
600-1000
85% rev's max, full throttle possible further up the rev range.
Changed to a organic performance oil
1000 on
Yippy!
And fully synthetic oil.
All the way though this I was told to warm it up till the Oil gauge moved, never let the engine labor, use the gear box up and down as often as you can, try and avoid motorway use.
I don't believe that you should thrash the life out of your engine right from the box, but too gentle use can glaze bores, lead to oil use and friction.
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First 200 miles
60% rev's max and never full throtle.
200-600 miles
75% rev max, full throttle possible further up the rev range.
Up to this point ran on very basic (but good) oil.
600-1000
85% rev's max, full throttle possible further up the rev range.
Changed to a organic performance oil
1000 on
Yippy!
And fully synthetic oil.
All the way though this I was told to warm it up till the Oil gauge moved, never let the engine labor, use the gear box up and down as often as you can, try and avoid motorway use.
I don't believe that you should thrash the life out of your engine right from the box, but too gentle use can glaze bores, lead to oil use and friction.
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