Interesting - I was not aware of this!
Say there are 2 engines. One runs for 6 hours, then 1 hour break and then another 6 hours.
Another engine runs continuously for 12 hours without a break.
If this is repeated several days, the stress on both engines will be identical then?
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You could repeat it for years - that's what long distance coaches and trucks do. A million miles on one engine/gearbox is very common, and there are lots of trucks that run sixteen hours a day with two or more drivers in the trunking sector.
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Believe it or not the shorter running time engine will be more (Thoguh infintessimally small) stressed.
Each start means getting the oil back up to pressure, and the metals heating up after having cooled down so expanding and contracting.
Edited by mss1tw on 25/05/2009 at 19:24
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Actually, since most of the wear is from cold, the engine with the fewer starts will have less wear.
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i dont see any reason the engine cant run 24/7 without overheating
i wonder if the wheel bearing grease and cv grease gets too hot with extended use?
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The Ice Road Truckers featured on the TV series recently used to leave their engines running continuously for the three month season because of the extreme cold, as far as I remember. They were only switched off when in the garage for servicing.
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I know its a bit different but when Stagecoach get a brand new bus they often run it for 24 hours routes permiting 7 days a week. They do this to make the most back of their £240,000 investment (the cost of a new bus) and it means the older less reliable ones get a good rest.
Many blackcabs run 24/7 too as they share the ownership.
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My Mondeo has been running for about 6000 hours of its seven year life, about 10%. It overheated once when the waterpump went, other than that its been fine. Compared to a lot of taxis its not even heavily used.
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Engines prefer to be run continuously. Not just car ones either.
When a helicopter landed behind my garden, I went to see and the pilot said he was early for a wedding he had been booked for and was waiting there until the time he was required. I said do you want to come and have a cup of tea? and the pilot said no he couldn't turn off the engine as it would cool down and the wear would cost £70 (or something like that) in maintenance, and it was much cheaper to burn fuel for an hour.
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In the days when company car tax was based on mileage I drove to Prague for a meeting in my 1996 2-week old Mondeo 2.0 mk1. About 15 hours continuous each way with much of it across Germany at a steady 110-120. The car still runs very nicely (I bought it from the firm).
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just dont go in a rover k series movilogo
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Agricultural tractors have an hour-ometer instead of a mileometer.
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Agricultural tractors have an hour-ometer instead of a mileometer.
As do fork lift trucks. Their servicing is based on hours run because the milage they do is too low in comparison to be meaningful.
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I once ran a 405 TD for almost 24 hrs solid didn't even turn when it was filled up, and that had almost 180k on and it was fine.
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I am searching, so far unsuccesfully, for details of some American who drove a Cadillac, somehow serviced while on the move, for tens of thousands of miles. The world record for continuous piston engined flight is something over 63 days. fuel, oil and food were hauled up on a rope by flying formation on a pick up truck driving over a salt flat. Crazy Americans but a good advert for Cessna and Lycoming.
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1966 150k north of Rome to Paris - basically nonstop. Wait for it, in a Bedford CA Van, with 3 drivers. took about 30hrs IIRC
Google maps shows it now as 22 hrs avoiding tolls/ motorways, as in those days much of the motorway network did not exist!
The advantage of the van was that you could change drivers without stopping with a little careful manouvering, altho we only did it at low speed.
There were a couple of scary moments, I remember that with yellow headlights ( at best described as inadequate) in the dark, we came across a section of road under construction. It seemed like a 30cm drop down followed by 30cm cliff back up, 20m later all at 60mph. It certainly woke up the non drivers. Une of the drivers was also dependent on very thick glasses. His tinted pair however gave no vision on entering an unlit tunnel in bright sunlight - the front passenger grabbed the wheel and took it thro the tunnel. Stopping in Italy was not an option.
p
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>>just dont go in a rover k series movilogo
I know not to bite anymore - however we did do 2000 miles in 10 days through Europe last summer and no problems in my MGTF (with a k-series!). We did over 600 miles through Germany at a very quick pace with only stopping for fuel!!
I also drove our old 214 from Teesside to London and back in one day when it was 11 years old and had 140,000 miles on it with no problems (other than a sore back!!)
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It is not unusual for one of our bulk blower lorries to be running at least 18 hours out of 24 in a normal working day, switched off only when refuelling, reloading or when the driver is taking a break.
Starting at 6am, driver goes to farm, engine is running whilst unloading (to power the PTO which drives the blower and tipping gear) repeat for up to four more farms, return to base, collect second load, repeat; on returning to base he refuels, night driver runs to a mill in Dorset to collect organic feed, returns about 5am, day driver starts at 6, etc.
Driver benefits most in very cold conditions as cab is always warm and he never has to defrost the windscreen!
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Most engines will break if run at max revs continuously, most are not designed for such treatment due to the high stress factors, unless of course the max revs allowed has been forced limited to within safe tolerances. Even an F1 engine only lasts for so long before it needs a rebuild or is discarded.
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We did do 2000 miles in 10 days through Europe last summer ...
and we did 3500 miles in 25 days around the western USA in 1964 - and again in 1966 - in an original Morris 1100, without overheating or anything worse than a bit of misbehaviour from the electric fuel pump and some wear on the rubber CV joints.
Certainly no reason why engines shouldn't run for very long periods, provided nothing runs out or wears out. Pumping engines in mills and suchlike were expected to do just that, and the longer-lived steam locos clocked up about 1½ million miles in 30 or 40 years.
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My Octavia used to be driven between 250-400 miles every day - in cold weather I kept it running between jobs for the heater. I once did 987 miles in one go (Bedford to Heathrow and back 3 times, then Bedford to Preston and back). The temperature needle rose to exactly 90deg within 5 minutes of a cold start and stayed precisely there no matter what conditions I was driving in (including, ahem, prolonged fast running from Gatwick to Bedford at 4am pre-M25 cameras).
In nearly 300k miles no engine work was needed whatsoever.
Dave TD.
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Stationary engines powering pumps, generators etc have often run continuously. It's just a matter of designing in adequate cooling. In the days before the national grid isolated properties often had private generators, some of these ran continuously for decades.
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I read a story a long time ago about a 1960's Harley Davidson Flathead engine found driving an irrigation pump in a remote shed on a farm somewhere Stateside. The farm was up for sale, and the outgoing owners claimed this engine had run for 'over 15 years' without being switched off. They'd change the oil with the engine running once a month using a system they'd rigged up to supply the new oil as the old stuff drained. That was all the maintenance it ever had. It was running at tickover day in day out.
It was switched off by the new owners, and dismantled for examination. Apart from the spark plug electrodes being worn away to virtually nothing, it was in remarkably fine fettle.
Wish I could find the story. It was amazing - photos and all.
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>>I said do you want to come and havea cup of tea? and the pilot said no he couldn't turn off the engine as it would cool down and the wear would cost £70 (or something like that) in maintenance and it was much cheaper to burn fuel for an hour.
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Couldn't you of just brought him out a cup of tea? lol
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So I suppose they can run until they need an oil change...
I have to say I sometimes drove from one to the next petrol station, and as long as you don't do it flat out, which you can't generally do anyway with laws and traffic, there is no problem.
It is also worth remembering that not just starting, but also switching a (turbo) car off can put some strain on things, so a bit of idle at the end might be a good idea.
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