Do modern engines need running in?
Discussion
NGRhodes said:
Very true.
I've read stories that some production engines are pre-run before being installed as a quality control (but also acts as a running in stage) but never looked into.
I remember having specific instructions for running-in fast-road and rally cams I used to fit to some of my cars many decades ago, so ensure no excess pressure on the tips ( before surfaces harden - I think).
Depending on the engine complexity (i.e. the number of systems and joints for coolant/oil/inlet exhaust, engines are often cold tested (typically a flow/pressure check of the system) and then on a 1 in XXX system, which varies, they will take an engine for a hot test, which is an extended dyno run with hot fluids, exhaust up to temp etc to check for leaksI've read stories that some production engines are pre-run before being installed as a quality control (but also acts as a running in stage) but never looked into.
I remember having specific instructions for running-in fast-road and rally cams I used to fit to some of my cars many decades ago, so ensure no excess pressure on the tips ( before surfaces harden - I think).
Edited by NGRhodes on Wednesday 22 July 12:31
But it's pretty much only to check for leaks in any gaskets/seals, not for any sort of run in.
IforB said:
Ah OK. It is the rolling road test I have seen being done. It still seems pretty brutal though. Certainly not a gentle functionality test. There was definitely redlining going on!
That is what I mean by does it really matter? If the manufacturer have given the car a good thrashing (for whatever reason) as part of the build process, then what else is gentle running in going to do?
From memory (and it's a long time since I was in a production facility) it wasn't redlining but you're right I may have underplayed it somewhat.That is what I mean by does it really matter? If the manufacturer have given the car a good thrashing (for whatever reason) as part of the build process, then what else is gentle running in going to do?
IforB said:
Are heat cycles important for example? Or is it just the bedding in of bearings and mating surfaces etc that is important? If so, how much really goes on?
I don't recall (and should really know) but it takes longer operation than the tests on the rolling road for mating surfaces to wear together, as I say the primary one is pistons/rings but you also have valve to seat interfaces, seal deformation etc - nothing catastrophic but they will all settle to a degree. Temperature would help with seals and gaskets and the like (some downstream exhaust gaskets have a softer metal component that deforms to create a perfect seal for example, heat will assist with this) but for the rotating internals, it's probably more easily expressed in terms of engine hours, I'd expect maybe 10-20 hours for the rings to be where they need to be, and probably the bearings as well.Plain bearings don't wear in, as a ring/bore would, but are tempered due to the high pressure created by the oil film between the crankshaft and bearing surface, in combination with the crankshaft pin lapping (very very fine directional surface finish in the direction of rotation, imagine carpet fibres) but they will harden in operation - they are still relatively soft so that any very small debris can be absorbed into the bearing itself.
Interesting point raised about wearing in cam surfaces, had not considered this but I expect it's ensuring that you get a good contact between cam and follower, so you're not putting big point loads from a high spot on a lifter into the cam surface for example.
RDMcG said:
I generally get factory delivery. Three GT3RS that way. 200km if that on day 1 . Race track within a few days. 5,000 km in three weeks as I have zero interest in all that keep mileage low palaver. Never had the slightest engine problem.
Robert Mitchell (owner of Apex at the ring) posted a video on youtube recently saying he never runs in engines either and hasn't had any issues. He just picked up a 620R and took it straight out onto the track. Mr.Jimbo said:
IforB said:
Ah OK. It is the rolling road test I have seen being done. It still seems pretty brutal though. Certainly not a gentle functionality test. There was definitely redlining going on!
That is what I mean by does it really matter? If the manufacturer have given the car a good thrashing (for whatever reason) as part of the build process, then what else is gentle running in going to do?
From memory (and it's a long time since I was in a production facility) it wasn't redlining but you're right I may have underplayed it somewhat.That is what I mean by does it really matter? If the manufacturer have given the car a good thrashing (for whatever reason) as part of the build process, then what else is gentle running in going to do?
IforB said:
Are heat cycles important for example? Or is it just the bedding in of bearings and mating surfaces etc that is important? If so, how much really goes on?
I don't recall (and should really know) but it takes longer operation than the tests on the rolling road for mating surfaces to wear together, as I say the primary one is pistons/rings but you also have valve to seat interfaces, seal deformation etc - nothing catastrophic but they will all settle to a degree. Temperature would help with seals and gaskets and the like (some downstream exhaust gaskets have a softer metal component that deforms to create a perfect seal for example, heat will assist with this) but for the rotating internals, it's probably more easily expressed in terms of engine hours, I'd expect maybe 10-20 hours for the rings to be where they need to be, and probably the bearings as well.Plain bearings don't wear in, as a ring/bore would, but are tempered due to the high pressure created by the oil film between the crankshaft and bearing surface, in combination with the crankshaft pin lapping (very very fine directional surface finish in the direction of rotation, imagine carpet fibres) but they will harden in operation - they are still relatively soft so that any very small debris can be absorbed into the bearing itself.
Interesting point raised about wearing in cam surfaces, had not considered this but I expect it's ensuring that you get a good contact between cam and follower, so you're not putting big point loads from a high spot on a lifter into the cam surface for example.
"Research indicates that most cams that wear out start to fail during the first few moments of operation. Many cams are irreparably damaged, even before the engine is started, because the basic rules of camshaft break-in have not been followed.
The cause of premature cam and tappet failure is metal to metal contact between the tappet and cam lobe. Should this contact occur due to lack of proper lubrication or excessively high pressure due to valve train interference shearing the oil film, then ‘galling’ will take place. When this happens, metal is transferred from the tappet to the cam or vice versa in a process comparable to welding. Microscopic high spots, which are present on all machined parts, become overheated due to friction and pressure and bond together, tearing sections loose from the tappet or lobe. These pieces of metal remain attached and create further local overheating during the following revolutions of the camshaft and lead to ultimate failure of the affected components"
I get the oil up to temperature and drive in a variable fashion, using all the revs and avoiding sitting for long periods on a constant throttle.
I don't know whether it's 'wrong' but it seems to work and I've done it for years. Even my old 1.9 PD TDI didn't use oil and they were notorious for it.
I've done it with every new car I've ever had and always will.
As far as the next owner goes, I didn't buy the car for him!
I don't know whether it's 'wrong' but it seems to work and I've done it for years. Even my old 1.9 PD TDI didn't use oil and they were notorious for it.
I've done it with every new car I've ever had and always will.
As far as the next owner goes, I didn't buy the car for him!
I drive near the docks in Southampton a lot.... if the boys and girls who drive the new cars on and off the ships are anything to go by....then none of us has to worry about "running in an engine"...cause believe me....those cars are ragged, so what ever you do will be undone by them anyway...on cold engines, especially in the winter
We had a diesel 1.9 pug 306, the book said oil change every 6k, now my mini wants a change every 20k or 2 years. So the oils must be better? the engines better in engineering tolerances/machined?
I do a higher mileage than most so the Mini requires an oil change every 7/8/9 months, I would not be happy with every 2 years....is that because the manufacturer wants to make the service intervals long to make car look cheaper? or the oils today that much better along with manufacturing standards?
When I had the pug, an oil change every 6k or so was expensive and not always done, but it never drank any, and never let us down (the engine that is...everything else did
)
My diesel 1999 V70 requires new oil every 10k, never had to top it up between services, bought it abroad, loaded it full of beer and wine, and from Belgium back to UK did between 70-85 mph. Engine has never let us down apart from a fuel pump about 18 months ago, and now on nearly 250k
Big ocean going ships engines last for ever....but they maintain them 24/7, which includes lubrication changes, which help them last longer, so as little as I know about engines, if it requires new oil, I change it, be it on age or miles.
Can it hurt a new car to change it's oil after a 1000 miles? I doubt it, but could certainly help long term. Red lining it on a cold engine would more than likely not help, but then that kind of driver is likely to visit the garage more often than not anyway
We had a diesel 1.9 pug 306, the book said oil change every 6k, now my mini wants a change every 20k or 2 years. So the oils must be better? the engines better in engineering tolerances/machined?
I do a higher mileage than most so the Mini requires an oil change every 7/8/9 months, I would not be happy with every 2 years....is that because the manufacturer wants to make the service intervals long to make car look cheaper? or the oils today that much better along with manufacturing standards?
When I had the pug, an oil change every 6k or so was expensive and not always done, but it never drank any, and never let us down (the engine that is...everything else did
)My diesel 1999 V70 requires new oil every 10k, never had to top it up between services, bought it abroad, loaded it full of beer and wine, and from Belgium back to UK did between 70-85 mph. Engine has never let us down apart from a fuel pump about 18 months ago, and now on nearly 250k
Big ocean going ships engines last for ever....but they maintain them 24/7, which includes lubrication changes, which help them last longer, so as little as I know about engines, if it requires new oil, I change it, be it on age or miles.
Can it hurt a new car to change it's oil after a 1000 miles? I doubt it, but could certainly help long term. Red lining it on a cold engine would more than likely not help, but then that kind of driver is likely to visit the garage more often than not anyway
I've always treated delivery mileage engines with care for the first 1,000 miles. It can't do any harm.
I have never really wanted to 'rag' a costly V8 or V12 (or any car for that matter) - there's no point.
It's interesting to watch Iain Tyrell on YouTube (for example) who always treats rebuilt engines with the greatest of care by running them in. I suspect he knows what he's doing.
I have never really wanted to 'rag' a costly V8 or V12 (or any car for that matter) - there's no point.
It's interesting to watch Iain Tyrell on YouTube (for example) who always treats rebuilt engines with the greatest of care by running them in. I suspect he knows what he's doing.
I've seen the video from the BMW motorcycle factory where they take the finished bike (a boxer twin, in this case) off the line, put some fuel in and prime the system then fire it up. The bike is then ridden 80-100 yards to the dyno where it is run up through the gears and given two full-throttle power runs up to the rev-limiter pretty much from stone cold. Every bike has this as far as I could glean from the video.
So, I reckon that nothing an owner could do would be 'worse' than this and running-in is not necessary. As an engineer, however, I would want my oil to be at least warmed through before giving it some!
So, I reckon that nothing an owner could do would be 'worse' than this and running-in is not necessary. As an engineer, however, I would want my oil to be at least warmed through before giving it some!
When I was having the engine for my bike built I spoke to a technical advisor at an oil company to pick their brains on what spec of oil to use for running in, they suggested semi-synthetic for the first 500 miles then switch to fully synthetic.
I'm also a beliver in moderate amounts of engine braking when running in as it loads everything up the 'wrong way'
I'm also a beliver in moderate amounts of engine braking when running in as it loads everything up the 'wrong way'
Majorslow said:
Buster73 said:
Running in , please pass.
Blimey...not seen one of those signs for a while....are you old as well? One of my neighbours has steadily restored a Mk3 Cortina 1600L estate, and rebuilt the 1.6 crossflow recently. He’s running it in as per the book.
The only new car I've ever had was run in mostly using cruise control. I set it for 65 on a long motorway run and just changed up and down 4th-5th-6th-5th-4th every few minutes so as to give it a range of revs...It didn't burst in the 2 and a bit years we had it and it's someone else's problem now. New bikes often have a rev limit/miles sticker on the tank, some new ones have LEDs or idiot lights which come on to tell you you're revving too high for the running in period.
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