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Soot particles have a "primary" particle size of 10-30 nanometres. A full flow filter can remove partcles down to 5 micrometres at best. In most diesels, soot is the main problem you have to deal with, however soot particles are so small, they can only be collected by bypass filter systems.Quote:
Originally Posted by jerryd
Hope this helps???
That person has given you bad advise :eek:Quote:
Originally Posted by jerryd
The full flow filter can not filter out the very small particles because it would restrict flow too much with a small micron filter element.
The bypass filter is there to capture the small particles. So it needs to have a small micron filter element. There is a flow restrictor in the port for the bypass filter so using the same element as the full flow filter will not achieve much filtration.
If the small soot particles are removed, oil change intervals can be extended. But it is best to use oil analysis to determine when to change it.
I have changed the stock bypass filter to a centrifugal unit that will remove smaller particles than the smallest micron bypass filter elements.
QDS $102-50 or $98 if you buy 3 drums.
Congratulations on the new improved method and publication isuzurover. :DQuote:
Originally Posted by isuzurover
There are many variables that alter the rate of soot buildup, but what sort of mileage range does the soot analysis show to be acceptable before changing the oil?
At say 10,000km is the oil always comprimised, or have you been able to get say 15,000km with more conservative driving?
Castrol RX Super - 5000k changes, zero oil consumption, very happy with it.
CHT
Fuchs oil, changed 5-10 000km depending on use. filter every 2nd change. It normally does not get started unless it has a minimum of 200km drive (To work) or driven all day on treks and staying hot. No oil use yet.:)
When I had to pull it down, not a drop of gum or build up anywhere
I don't have reasonable stats post turbo, and am about to fit a bypass filter...Quote:
Originally Posted by nice1guv
However when it was NA, soot levels got to about 1.3% by 20k km. There seems to be a lot of debate about what is acceptable. Smaller diesels owners seem to think >1.0 is high, however many heavy diesels don't have the oil changed till >3.0%.
My 10c Worth,
Since landing in NQ on the advise of the local Landy Guru I used 2 sumps full of Penrite HPR Diesel. Wasn't happy and could no longer get hold of the Penzoil MA 15w 40 Long Life that I used to run.
On advise from Dave (BLKNGHT) Friday night I did a change n used Nulon 15w 40 Semi Synthetic for Diesels.
Did 250k with the boat on yesterday and its heaps better.
It wakes up n gets outta the sump quicker but still keeps the rattles down even @ an Exhaust temp of 580c
So I'll buy another drum. :D
From what I've been told, soot condemnation limits vary according to engine families and this can only really be determined by using UOA and working with the engine manufacturer and oil blender, something none of us can do.Quote:
Originally Posted by isuzurover
Basically some oils can tolerate far higher levels of soot than others without engine wear, as do some engines.
My oil analyst always reckoned i had too high levels in both the Patrol and 300Tdi and yet neither ever exceeded 1% IIRC, with the patrol never exceeding 0.8% at 20,000km.
As Ben said, some operators use up to 3% (with the manufacturers OK) as the condemnation limit in the large over the road trucks, and usually it's the Fe that determines the oil change, not the soot these days in these vehicles using the synthetic oils, particularly when using centrifuges for the by-pass filter.
and FWIW I use Fuchs Titan Ultralube in the tractor and ATM I've been running Penrite (oh the shame...) Diesel SP 10W-40 in the Landy and Patrol. It's a low SAPS (1% ash IIRC) synthetic oil for Euro IV spec diesels so it'll be interesting to see how it looks in some old school engines when I eventually get around to getting some more samples done.
The reason I started using it was the add pack is reputedly very strong and it has a NOACK volatility under 9% which is very good, even though I believe it's a Group III/IV/V blend and it's a bucket load cheaper than Delvac 1. My oil analyst had been having 'issues' with some of Mobil's high end brews in the last few years in very taxing/extreme service applications. Some of these blends were stand out performers and the industry benchmark in the past, which is a real shame, so we changed.
I'm only using 10,000km OCI's in the Patrol these days (factory recommend 5,000km) as it's doing shorter trips, even though it's not towing and i haven't been oil testing either.
FWIW, the first few tests I did on it years ago were with Fuchs Titan Ultralube using 500ppm sulphur diesel and it could do 10,000km with ease, (highway towing) not bad for a dirty direct injected engine so the good mineral lubes are pretty damned stout.