Running in...
Posted By : Simon Adamson, 27-May-2005, 12:31pm
Gently does it! It's an old engine, so the old method is probably best (unlike modern motors that you can apparently thrash straight away).
My advice would be to try to keep the revs below 3,000 RPM for the first 500 miles, but most importantly not to let the engine labour at any time. I change the oil and filter at 500 miles. During the next 1,000 miles, you can gradually raise the rev limit, particularly for short bursts when fully warm. I would change the oil and filter again at 1,000, and then follow your chosen service interval (maybe 3,000 - 6,000 miles / 12 months).
The way the engine will bed in depends a lot on how it was rebuilt (bearing clearances / cylinder bore honing etc.) and also the choice of oil. Personally, I'd always stick with a good 20/50 grade. You will most probably find that the engine will burn a bit of oil to begin with, but consumption should rapidly reduce over the first 1,000 miles. Sometimes it can take at least 3,000 miles before the engine's at its best.
Enjoy!
My advice would be to try to keep the revs below 3,000 RPM for the first 500 miles, but most importantly not to let the engine labour at any time. I change the oil and filter at 500 miles. During the next 1,000 miles, you can gradually raise the rev limit, particularly for short bursts when fully warm. I would change the oil and filter again at 1,000, and then follow your chosen service interval (maybe 3,000 - 6,000 miles / 12 months).
The way the engine will bed in depends a lot on how it was rebuilt (bearing clearances / cylinder bore honing etc.) and also the choice of oil. Personally, I'd always stick with a good 20/50 grade. You will most probably find that the engine will burn a bit of oil to begin with, but consumption should rapidly reduce over the first 1,000 miles. Sometimes it can take at least 3,000 miles before the engine's at its best.
Enjoy!
Running in...
Posted By : Nigel Gibbins, 27-May-2005, 03:06pm
In all honesty, you should never have to take it easy with a new engine. We'll maybe on the first heat cycle anyway, you can never be totally sure that
the heat expansion won't cause something to go somewhere it shouldn't. You should also turn the whole engine over by hand (on the pulley nut) a few
times before trying to start it frst time - just to check the pistons and valves don't hit each other. If you can't turn it or it suddenly stops then
there is a problem.
I have strong doubts about engine builders saying "keep the revs down for the first xxx miles" as IF the engine is built properly then it will be good whatever you do with it after the bedding in period (30 mins).
Running in needs to do three things - bed in the piston rings, bed in the bearings and run in the new camshaft (followers and bearings). Do not let the engine idle for any time after you start it for the first time, you MUST take it for a half hour drive... this will bed the piston rings in propely (otherwise they'll glaze) - take it easy on this run though. You need to do lots of hard (ish) accellerating from low revs to mid revs and keep an eye on the oil pressure and the engine temperature. When you come back from this run, you should change the oil and you're ready to go... and that's a lot more running in than any of our race engines get.
I suppose the racers get the most engine builds done of everyone except a 'professional' (about once a year) and our engine are built to high tolerances. We can't afford to run them in in the conventional way - my last engine did about 15 mins running in on the rolling road before going racing where it was pushed all the way to 8,000 rpm. That engine lasted two years (of racing) and I'm now waiting for my next engine which will be pushed much harder than that one was.
One racer has his engine builder rev the engine up three or four times on the dyno... and then that's all it gets!!!
I have strong doubts about engine builders saying "keep the revs down for the first xxx miles" as IF the engine is built properly then it will be good whatever you do with it after the bedding in period (30 mins).
Running in needs to do three things - bed in the piston rings, bed in the bearings and run in the new camshaft (followers and bearings). Do not let the engine idle for any time after you start it for the first time, you MUST take it for a half hour drive... this will bed the piston rings in propely (otherwise they'll glaze) - take it easy on this run though. You need to do lots of hard (ish) accellerating from low revs to mid revs and keep an eye on the oil pressure and the engine temperature. When you come back from this run, you should change the oil and you're ready to go... and that's a lot more running in than any of our race engines get.
I suppose the racers get the most engine builds done of everyone except a 'professional' (about once a year) and our engine are built to high tolerances. We can't afford to run them in in the conventional way - my last engine did about 15 mins running in on the rolling road before going racing where it was pushed all the way to 8,000 rpm. That engine lasted two years (of racing) and I'm now waiting for my next engine which will be pushed much harder than that one was.
One racer has his engine builder rev the engine up three or four times on the dyno... and then that's all it gets!!!
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Running in...
Posted By : Philip Brammer, 28-May-2005, 10:15am
Sorry Nig, don't agree with you on this one (tounge sticky out thing). Even my almost brand new Corsa advises in the handbook not to exceed 4000 rpm or labour the engine for the first 600 miles. Running in is very important for an engine and allows a very tight new engine to free off under lower stress levels. Racing drivers have always been an impatient bunch who enjoy rebuilding their engines on a regular basis so I see where you are coming from, but most of us want a nice quiet reliable engine with no oil leaks and no oil burning. so my vote is for Simon's advice!-
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Posted By : James Carruthers, 28-May-2005, 10:20am
Oh dear... oh dear oh dear...
That 17 mile old Corsa I had for a rental car last month will be knackered soon then!
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Posted By : Philip Brammer, 28-May-2005, 10:28am
Lol, Why am I not surprised James?? Sigh......-
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Posted By : Jason Chinn, 28-May-2005, 10:35am
Surely the first thing you do in a hire car is establish peak power by thrashing the guts out of it in each gear. Or of course if you need to bed in that new clutch you just get towing a Vitesse home with your 1 litre Hyundai Getz!!-
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Posted By : Philip Brammer, 28-May-2005, 10:44am
Don't listen to them Ian, they are trying to tempt you over to the dark side.......Heathens!!-
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Posted By : James Carruthers, 28-May-2005, 11:14am
Quite obviously I would never treat my own car - I am going to have to go through the pains of running in very soon - what a nasty thing to have to do - especially when you have built a beasty engine.
Still - the Corsa has probably been fixed by now - it was making an odd thuddy noise under load by the time I gave it back - new cars eh!
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Posted By : Ian Johnson, 02-Jun-2005, 10:18am
Dark side? That always seemed far more fun to me anyway... Always fancied a black Vitesse with black leather, lowered with plenty of chrome and maybe some flames fown the side - just for the sake of it, surely the Triumph of choice for Darth Vader...!
Dark side in what way? You mean they want me to drive modern cars? Corsas are just a little bit too small and as for a Hyundai - I mean really - they might be really good cars but I live in Liverpool, I need any excuse not to get beaten up. I'll stick to the Mark 4 Golf instead! Sorry Jason!
P.S. Are they any good? Can't keep putting this many miles on the six!
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Posted By : Andy Vowell, 28-May-2005, 11:25am
Not all race drivers are impatient, (eye rolly thing) I always run my engines in. 500 miles if possible though sometimes less as I'm not road legal. I do rebuild my engines every year and the only one I did not run-in blew on the 4th race. (an emergency build after other problems)
Not running-in may or may not have not been the ultimate cause of a conrod escaping through the sump, but I firmly believe that at least 500 tender miles below 3/4000rpm on a newly built engine can only pay dividednds later on.
Andy-
Running in...
Posted By : James Carruthers, 28-May-2005, 01:14pm
I've read up lots of opinions on this - and it seems the answer lies somewhere between the harsh and the gentle.
The science behind it - as far as I understand it...
Piston rings need to match themselves to match the cylinder wall - they use the honed crosshatch pattern to do that. Essentially it works as an abrasive.
Pistons rings don't push themselves outwards with their spring tension - instead the huge gas pressures created in the combustion chamber get behind them and push them outwards.
They need to exert enough pressure on the cylinder walls to make this happen - imagine using a file to grind something down - not enough pressure and it wont do a thing. In fact if you do just drag a file across something you get a very harsh surface - not something suitable to seal the combustion chamber.
The way to exert pressure on the rings is opening the throttle fully and loading the engine. If you don't do this soon enough then the crosshatch will disappear and you have to start again (ie take the engine apart to rehone it)
The rings are quite easily matched to the cyinder within the first half hour of driving on the road.
Note that running in on a dyno is more agressive than on the road as driving on the road puts more strain on the engine due to wind and tyre resistance - so not fully comparable.
I am still unsure of the rev limit and mileage you should do after the initial running in - it seems that you have to do some mileage in a reasonably gentle fashion - but "gentle" is relative - and it doesnt mean driving at 2000rpm everywhere - even running at 50% of an engines capacity is 3,500 or so. Also running in an engine with a race cam is going to be at a higher rpm due to lower gas pressures at low rpm.
That's what I've read up anyway - bring on my new engine
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Running in...
Posted By : John Davies, 28-May-2005, 06:57pm
All,
I'm not getting into the hard/soft argument, just want to add a couple of points:
1/ Especially on that first run accelerate then back off alternately. Stay in third gear to ensure that as they say, the engine doesn't labour. The rings are indeed forced against the cylinder wall by chamber gas pressure, as James says, but they need to be re-lubricated after that. The chamber pressure will be negative if the engine is turning against a closed throttle and oil will be sucked up into the bores on the overrun.
2/ For the first fill up of oil, don't be tempted to use Duckils best green magnetic synthetic lubricating fluid (nothing but the best for my engine - certainly not that old fashioned 'oil'!). Apart from anything else, you will throw it away after 500 miles, and what you are paying for in that stuff is long life and anti-wear additives, which you don't need. Buy the cheapest oil you possibly can. I use B&Q's recycled oil.
John-
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Posted By : James Carruthers, 28-May-2005, 07:12pm
Another few points from wot I av reed...
Backing off the accelerator brings up oil, which not only lubricates but washes away the metal that should be left over from the running in.
Supposedly, if you are able to run the rings in within 30 miles or so - you should change your oil straight away too. So even more reason to use cheap stuff...
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Posted By : James Carruthers, 28-May-2005, 07:14pm
Of course when I say throw away I mean "dispose of in an environmentally responsible way"
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Posted By : Philip Brammer, 29-May-2005, 08:45am
Ermm, I'm not sure I agree with all that (theres a surprise!!) cos the 4 stroke engine runs on a 'suck, squeeze, bang, blow' principle so on the suck or intake cycle the piston is creating low pressure to draw in petrol/air therefore no need to keep baccking off as the engine does it for itself every 4th stroke of the piston. Also the only lubrication a bore gets (apart from the occational glass of red wine in my case!) is from splash and mist created in the crankcase. The bottom ring, the scraper or oil control ring, has the job of making sure enough, but not too much, oil is left on the bore surface to lubricate the piston and compression rings. If any more than that gets 'sucked past' the scraper then its not doing its job, and the engine will burn excess oil. Apart from that there are loads of other engine bits that have to get to know each other as well!
Don't add any of these 'low friction' addatives Ian until your engine is well run in, in my opinion anyway.-
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Posted By : Philip Brammer, 29-May-2005, 09:12am
Sorry, overlooked a bit. If its the compresion from the ignition of the petrol/air mixture that keeps the rings sealed against the bores and piston, and not the 'spring' in the ring (bum bum) then what keeps the piston gas tight during the exhaust, compression and intake cycles?-
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Posted By : John Davies, 29-May-2005, 10:30am
Philip,
Never noticed blue smoke on the overrun on a worn engine? Part burnt oil, sucked up into the cylinder. Okay, that's with worn or sticking piston rings, but 'sticking' means not moving out from the groove under cylinder pressure.
I think we are arguing about relative details. Yes, to all your points, but there is more pressure in the burn stage of the cycle and more suction on the overrun than at other times.
John-
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Posted By : Andy Cook, 01-Jun-2005, 05:05pm
When I replaced the Engine in my GT6 about 10 years ago now, I had a high oil consumption and a fairly smokey engine even after about 500 miles of running in. I thought this can't be right so I phoned up John Kippings who supplied the Engine. They immediately asked had I used running in oil? I had to confess that hadn't even heard of the stuff before??, Kippings said, that I needed to run in using running in oil and unless I had done this then the rings would probably not bed in properly and oil consumption would always be high and the Engine would smoke. They suggested that I changed the oil for running in oil and continue to run in for another 1000 miles. I was a bit sceptical, I just thought oh yeah they are trying to wriggle out of replacing what could be a faulty recon engine, however I tried the running in oil and was well surprised when it did the trick. The oil consumption gradually got better and after a few hundred miles it was no longer smokey. 50,000 miles and 10 years on it's been a really good Engine, a real smooth runner and still holds a good oil pressure (of just over 60lbs per sq ") even when pushed hard. Yes I do have to top the oil up every now and then but that's only to be expected after 50K miles plus it tends to leak a bit of oil from the back of the rocker cover and the front pulley which must be using a bit of oil.
Looking at the owners manual it appears that Triumph supplied their cars with running in oil and this was scheduled to be changed at the first service. So by design our cars were meant to be run in using running in oil, this is much thinner viscosity than normal Engine oil.
I'd therefore say that if you are running an Engine in make sure you use running in oil and run in for 1000 miles or so. Keep it down to say 3K revs for the first 500 miles with no hard acceleration or labouring then over the next 500 miles gradually increase the revs and accelerate a bit harder. Hold off using the full potential until about 1500 miles or so.
I was really surprised when I purchased a new BMW MINI last year in that it came with strict instructions in the owners manual on running in and the dealership even stressed this further when I picked the car up. The recommended running in was for the first 1,250 Miles drive at varying engine speeds, without exceeding 4500 RPM or 90MPH, avoid putting the accelerator in full-throttle after the 1250 Miles engine speeds can gradually be increased up to the 6750 red line. So even some modern cars need running in.
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Posted By : James Carruthers, 01-Jun-2005, 08:52pm
Usage of running in oil also works with the "hard" theory.
Thinner oil = more wear on the rings...
I still reckon, from all I have read, that you need to labour the engine for the first 30 minutes of running on the road. After that you take it easy for the following 500. You can push it more after this - but the idea of running it gently is so that you can keep an eye on everything.
I shall be using this method with my own engine in the next month or so.
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