Dockhead
Well-Known Member
Anyone do oil analysis on their main engines?
Any lab to recommend? Tips?
Any lab to recommend? Tips?
One part of the fleet was put on a shorter oil change regime and that did pay off
Years ago when I ran transport I was talking to a mechanic about the make of the next HGV I was going to buy, he said that Mercedes Truck Engines lasted longer as they had bigger sumps so the engines had more oil. A friend in the 1960's whose father ran haulage was given a Austin Healy Sprite for his 21st Birthday and immediately changed the engine to Diesel Engine Oil as with it being a Heavy Detergent would last longer plus he would change the oil every year. And after reading about the Volvo owner whose car had done over 1 million miles with the same engine it was because he changed the oil every 3000 miles.
The "classical" method of wear particle analysis (as opposed to the standard spectroscopic wear element analysis), IIRC, is known as a ferrogram (or ferrograph?) and involves flowing the oil sample over a microscope slide in a strong magnetic field.My understanding is that oil analysis is useless on a one-off basis; that it needs to be done routinely at the same point in the oil change cycle so that trends can be identified and if necessary action taken. I suppose that really bad wear might show up as metal particles, but @ducked suggests that standard analyses don't pick big particles up!
Thank you for this detail. In another field entirely, the automated counting of penguins in aerial photography is an established technique, so I think you're right when you suggest that modern analyses will use an automated method. For penguins, it's probably more reliable than human counting; we get tired and miss things. My former colleague worked on developing the techniques, and I helped at an early stage by check counting a few images!The "classical" method of wear particle analysis (as opposed to the standard spectroscopic wear element analysis), IIRC, is known as a ferrogram (or ferrograph?) and involves flowing the oil sample over a microscope slide in a strong magnetic field.
The ferrous wear particles settle out by size, and the smear is then microscopically evaluated by a human expert. I believe this is/was quite expensive and mostly just works for ferrous particles, which bearings arent.
I imagine by now there are more automated methods of particle scanning and counting, Coulter-counter stylee, perhaps involving lasers, but I dont know anything about such recent developments.
Being long ago slightly involved in the biosciences, I would think a particle size separation could also be achieved by rate-zonal centrifugation in a sucrose density gradient, but I dunno if this has been tried in this field.
It isnt part of the standard analysis supplied by, for example, Blackstone Labs (the big name in the field) but IIRC they do mention the size of a post-centrifugation smear, which will probably be a mixture of wear particles, soot, and solid oil polymerisation products aka varnish.
IIRC the standard spectroscopic wear element analysis CAN be modified to cope with big particles by acid digesting the sample, but this is not routinely done.
I did come across a UK-based lab that provided particle-size distribution data as part of thier standard analysis at punter-friendly prices but cant remember who they were, and, from a quick look, couldnt find them ont internyet, but there are quite a lot of companies advertising that sort of thing. I dunno how they did it but would guess it involved laser scanning.
EDIT: Might have been these people
LubeWear.com
In which case the enhancement seems to be acid digestion, they have moved to a harder sell presentation than I remember, and I dont see any published prices
But what evidence if any is there that the Volvo car engine lasted such a long time “because” of the extra oil changes?…….. And after reading about the Volvo owner whose car had done over 1 million miles with the same engine it was because he changed the oil every 3000 miles.
Automated image analysis of penguins, eh? Young people today dont know they are born!Thank you for this detail. In another field entirely, the automated counting of penguins in aerial photography is an established technique, so I think you're right when you suggest that modern analyses will use an automated method. For penguins, it's probably more reliable than human counting; we get tired and miss things. My former colleague worked on developing the techniques, and I helped at an early stage by check counting a few images!