Q on long idling diesel

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illusion_, Sep 24, 8:46pm
Just a query. With, just for example, an RD28 nissan diesel(non turbo), would any likelyhood of premature wear/damage be caused by idling it for very long periods of time. Am thinking perhaps as a slow running stationary engine. Cooling would not be a problem. Fairly light loading.

Thoughts?

Thanks

serf407, Sep 24, 9:07pm
I think what is important is the quality of the engine oil and engine oil filters that you use and the the frequency of the oil changes etc.
It also depends how good the engine oil pump and engine oiling/ lubrication system is at low rpms. Some oil systems with wet sumps do not perform at steep angles and low rpms so sometimes there ar dry sump kits to pump engine oil in to ensure adequate engine oiling.
If the engine is stationary in a dusty environment make sure the engine air intake is kept clean and the radiator fins are not clogged.

snoopy221, Sep 24, 9:09pm
Old enough and done enough miles and has good oil pressure and frequent changes .
No Immediate Worries.
{If ya just put new rings 'n' bearings in it}
No Way

Edits to add.
post#4 is an LD28.

Chain Driven
NOT AN RD. BELT DRIVEN UPSTAIRS

DEFINATELEY

Put an hour meter on it and check belt wear with prolonged idling.

K

keith190, Sep 24, 9:16pm
I have a LD28 running a irrigation pump over summer.It sits at half throttle 24/ 7 for as long as it is dry.sometimes for a couple of months.Never had a problem in 10 years. We are using 3.5 litres/hour @28/32 hp requirement

strobo, Sep 24, 9:23pm
The LD28 would be a better engine for that agree with keith #4 was on my mind before I read his post .Chain drive cast head as opposed to RD alloy head and cambelt. Not to say the rd28 wont do the job as they are both great engines ( in their day).

tweake, Sep 24, 9:23pm
idling for long periods will glaze the bores.
plenty of talk of fixes to mines vehicles that sit idling for long periods.

half throttle is ok as that puts load on the rings and makes them work properly.

illusion_, Sep 24, 9:24pm
interesting . thanks . so perhaps the LD28 could be an even better way to go

strobo, Sep 24, 9:32pm
otago Polytech had an old experimental diesel engine engine running continuously on sunflower seed oil for long periods ,just above idle , for months and months on end only stopped for teardown and measurement, not sure the results but don't see any problem with what Op is doing with that what ever it is.

illusion_, Sep 24, 9:37pm
the (bright - or not) idea, just in the thinking stages as yet if for a genset to recharge batteries when needed. possibly up to 4 or 5hrs a day but rather as a backup rather than every day.

like I say . just thinkin.

illusion_, Sep 24, 9:39pm
yeah . thanks . am sorta more a fan of the 6cyl though. smoother, quieter, etc

strobo, Sep 24, 9:40pm
mines vehicles . understandably bad news on any engine. Diesel ignites under sufficient compression which is plenty enough load on rings anyway.The higher speed jap diesel engines are a bit more over squared requiring slightly more revs to achieve a better torque curve , depends what op is doing with it really isnt that true?The nissan ED33 / 4 cyl was a great wee stationary motor back in the day too i remember.

bwg11, Sep 24, 9:42pm
In my experience an "pre common rail" diesel like the LD28 would have no issues with such use other than what comes out of the pipe the first time it is opened up after such use. I have no experience of treating a common rail to this abuse but would be wary.

stornello, Sep 24, 9:53pm
The LD28 has a camchain, but the injector pump is belt driven. and not changed very often as some think it chain drive. There were industrial versions, so a better choice than the RD28.

intrade, Sep 24, 10:35pm
Old Diesel can idle for ever solong as they reach correct operation temperature.
The problem is on marine direct we water cooled who never really reach operation temperature at idle and new Diesel with loads of catalisatores dpf and SCR. These should not idle all day as they need a constant continued load 2200 rpm my manual on my Passat states usually 50 km at this rpm with load or the filters start to block up.

kingfisher21, Sep 24, 10:57pm
On the other side, reminds me of when I used to work in a remote rock quarry, we had a Screaming Jimmy, 6-71 Detroit, that was started up 1st thing in the early morning and instantly ran at full throttle powering a generator, used to scream it's head off for up to 20 hrs a day.

stornello, Sep 24, 11:13pm
They sounded like they were doing 8,000rpm, but pushing it to be 2,000.

mrcat1, Sep 24, 11:47pm
Jimmys love doing that, you try and make it idle for any length of time and it will just stuff it.

mrcat1, Sep 24, 11:49pm
Can you use a smaller engine and just make it work harder as with prolonged idling in a diesel they will glaze bores, not maintain a high enough temperature in the combustion chamber to burn the fuel properly and in effect they start washing bores and end up with fuel in the sump.

mrfxit, Sep 25, 8:34am
Could get around any glazing problems in your start up / shut down procedure.
Eg:
Start up = run 2 minutes to warm up then 2 minutes of varied modest revs
Shut down = varied revs for 2 minutes but more aggressive on the revs.

Could even make a bit of fun with it by building a small shed next to the engine & fitting it with a steering wheel & peddles etc.
Would help isolate noise as well.

illusion_, Sep 25, 9:11am
heh . yeah

I dont see the glazing as being likely though as it would be running at "normal" temperatures. Was thinking at around 1000rpm . maybe 1200.

Could go a bit faster if needed but the main point of running it fairly slow is to minimise noise, vibration, and consumption. So going with a smaller engine while just possibly uses less fuel, certainly increases the first two.
REALLY quiet would be the aim. Like 100ft away and you cant hear it.

However . all the above have given lots to think about, and it's only thoughts at this stage. Thanks for your input. Much appreciated.

mrfxit, Sep 25, 11:08am
At low comparatively revs such as 2000rpm & under AND as a stationary engine, theres no real need to consider the issues around too little or too much back pressure from the exhaust system.

With that in mind, you can run a few mufflers inline (or near to inline) to get the lowest sound AND tone.
I would suggest trying a very large muffler then down to progressively smaller mufflers as you need to get the sound level desired.
Tone has a lot to do with total distance heard from.

As for vibration, custom mounts are going to be needed anyway & (again) with it being a stationary engine, you can choose large but relatively soft mounts

Fuel consumption can be a tricky thing due to each engines basic design.
Eg: Some are best at 1200 but can be pretty bad at 1000 or 1400.

It's the old story of "my car is cheapest at 105kph but drinks like a fish at 95kph" which does have a certain amount of truth.
CC plus torque plus rev's plus load.

An idea for economy & mufflers fitted, could be to use a vacuum/ eco gauge & rev gauge to check load & revs as you add mufflers.

illusion_, Sep 25, 11:38am
correct on the mufflers thing. was already thinking that way. there's also the mechanical sounds (smoothness perhaps) that come into the quietness equation, which it why I tend to steer away from less than 6cyl options. like an old lister is proven to be good of course, but you cant get right away from that clatter and thump no matter how good it is.

fungles, Sep 25, 2:45pm
My TD27 runs an alternator and burns waste oil as fuel. Every 100 hours or so, I just give it a good rev to blow the soot out, runs for hours at 1000 RPMs. every few days charging battery banks,,, I expect it to see me out.

illusion_, Sep 26, 10:21am
very much what I had in mind but with a 6 rather than a 4 and running pump diesel

thanks for that info

intrade, Sep 26, 10:48am
2.1 Isuzu are reasonably quiet Japanese have one advantage over old euro Diesel they are not as noisy but also don't generate as much power from the fuel as a euro like a VW or fiat