Question for Doug Hillary regarding oil analysis

[REDDOG]

Doug Hillary,

I have always found your posts very informative and can remember you posted what you used for "limits" with your DD engines a while back. You shared your TBN and TAN limits with me a short time ago and I would very much like to know what you used for wear metals limits, viscosity, soot, etc.

I am monitoring a small fleet of fire engines (CAT and Cummins engines)and would appreciate any advice you could give. As you can probably imagine these engines see low mileage per year and are monitored/maintained in terms of hours, as they spend most of their time idling and/or pumping water. I would imagine though the operating conditions are very different from over the road service, the alarm limits would still be very similar.

I have recently begun monitoring the TAN levels based on our previous discussions. Any insight you could give into balancing optimum engine longevity/reliability and maintenance costs under these conditions would be appreciated.

Thanks very much in advance,

REDDOG

 

[Doug Hillary]

Hi,
REDDOG - The following data is what I used/use and in all cases it is still current

My limits - actual limits I reached from time to time are shown thus [ ? ]

Iron - 150ppm [ 221ppm ]
Copper - 30ppm
Lead - 30ppm [ 43ppm ]
Soot TGA Mass % - 3.5-4% #
TBN - 1 (D4739)
TAN - 7 (with TBN around 2) [ 7.7 with TBN @ 1.90 ]

The following condemnation factors that were NEVER reached with any of my engines but would have been the precursor to more research and an OC with monitoring via reduced UOA intervals are;

Viscosity @ 40C - >40% increase or Pentane insolubles % - >1% (D893)
Water vol % - >0.30% (D1744)
Fuel vol % - >2.5% (D3524)
Glycol max - >trace (D2892)

I always monitored ferrous metals via a PQ Index reading

# In this case even >5% would have been OK by me if Iron was below 150ppm (at say 125ppm) and all other condition factors were OK too, as I am very aware of the excellent soot handling capabilities of the synthetic lubricant I use. NOTE: This may not be the same for lessor lubricants

* Viscosity was always very close to new throughout the OCIs and in all engines - over several years and millions of kms. This was primarily due to the synthetic lubricant used and IMO the use of centrifuge oil cleaners. The centrifuge was cleaned at every second OC but had the capacity to go to three OCI without cleaning. Donaldson ELF FF filters were used and changed at each OC

In Interstate use around 100kkms was the safe/predictable operational limit for the lubricant - either of soot or iron limits were reached about then. Top up averaged around 6kkms per litre. No oil was added during the last 20kkms of an OCI as the oil was let run down to the "Low" mark. Normal operational oil level was about mid point "Full" to "Low" on the dipstick. Higher levels just raised the consumption rate

In city use one year (40kkms) was about the maximum operational life for the lubricant as soot condemnation levels were reached about then. Low TBN or high TAN reading were never a problem in this use. City use for me is just that - no rural running and long periods of idling in traffic

Operational ambient range = -10C to 45C

 

[jaj]

Doug

Did you maintain the same meticulous records for tires, brakes, and the rest of the package?

 

[Doug Hillary]

Hi,
jaj - Yes I kept very good records for tyres, brakes, fuel usage and cooling system mainenance(coolant analysis done monthly). This was all part of my training via Daimler-Benz (at Unterturkheim and Worth) - I never forgot!!

The running cost records were updated weekly and a P/L estimate undertaken for each vehicle at that time - fixed costs are of course known. I started my business off in 1988 using an Amstrad computer and updated as technologies allowed

All running costs were computed as cents per km to two places!
This included repair and maintenance, tyres, wages and fuel but brakes were not a major issue really - Jacobs engine brakes are a great tool!

Michelin tyres were my "standard" for instance but Bridgestones with Michelin caps were most cost effective. I only capped once and then sold off the cases

In trucking the main cost areas are wages, fuel - the others are less important in real terms. Minimising downtime is the key to profitability and it starts with the selection of the right specification equipment! I ran courses for Fleet Owners on this subject as part of my Transport Consultancy Business

Many Australian Fleets use all or some of my Fleet Management systems including programmed maintenance and Workshop control

 

[REDDOG]

Doug,

Thanks for the great response! This is exactly what I was looking for.

I will probably set my soot levels a bit more conservatively, 3%, as I will not be using Delvac 1.

There has been much debate on BITOG about the true value of oil analysis, especially in regards to actual engine wear. Did you find any correlation at all between metal uptake rates and tear down results for the same oil in the same engine family?

Thanks for sharing your experiences so freely. I always look forward to your posts!

REDDOG

 

[Jim Allen]

Doug: Great, informative post above.

What struck me was your mention of oil levels. I quote, "Normal operational oil level was about mid point "Full" to "Low" on the dipstick. Higher levels just raised the consumption rate."

This falls right in line with my own observation in various engines of the last 40 years or so. There are many on BITOG that strongly advocate maintaining to "full" in all circumstances... some apparently pedantically enough to perhaps use eye-dropper amounts to top off. That last was exaggerative humor, but you get the idea.

Topping off before the "Add" mark may be more advisable in an engine with low sump capacity, but even then, windage is still a factor and I have always thought, intuitively at least, that a bit more space between the oil level and the crankshaft is not a bad thing. Windage trays, of course, render that a moot point but otherwise a slight loss of oil capacity may be better than constantly churning and aerating the oil (which may increase oxidation rates, right?). Exceptions might be some older engines that rely more on splash than the newer ones. Emission laws seemed to have rendered excessing splash a bad thing. Any comments?

 

[OVERKILL]

Originally Posted By: Jim Allen
Doug: Great, informative post above.

What struck me was your mention of oil levels. I quote, "Normal operational oil level was about mid point "Full" to "Low" on the dipstick. Higher levels just raised the consumption rate."

This falls right in line with my own observation in various engines of the last 40 years or so. There are many on BITOG that strongly advocate maintaining to "full" in all circumstances... some apparently pedantically enough to perhaps use eye-dropper amounts to top off. That last was exaggerative humor, but you get the idea.

Topping off before the "Add" mark may be more advisable in an engine with low sump capacity, but even then, windage is still a factor and I have always thought, intuitively at least, that a bit more space between the oil level and the crankshaft is not a bad thing. Windage trays, of course, render that a moot point but otherwise a slight loss of oil capacity may be better than constantly churning and aerating the oil (which may increase oxidation rates, right?). Exceptions might be some older engines that rely more on splash than the newer ones. Emission laws seemed to have rendered excessing splash a bad thing. Any comments?


Jim:

Touching on this: A 302 Ford will be faster run 1 quart low at the track due to windage...... So you are definitely correct.

 

[Doug Hillary]

Hi,
REDDOG - Thanks
used oil analysis IME have proven to be a great oil condition monitoring tool. IMO they are less effective in accurately measuring engine wear unless you embrace them in an all emcompassing way. This is by trending within an engine family over much time and/or distance. That said some excessive wear indications may present themselves especially when the engine's metallurgy is known and the wear metals are complimentary (copper, lead etc)

Wear metal uptake rates are the way I monitor an individual engine's health. Sometimes spikes occur for unknown reasons but once the trends are established these can usually be discounted. People also forget that wear metals accumulate within the lubricant until they are drained out, this is why the final UOA at the OC point is so valuable - it overwhelms and can be used to confirm the interim used oil analysis in this regard

Wear metal levels from programmed used oil analysis co-related to the condition of the components at tear down IME by confirming that the wear metal limits set were reasonable and sustainable

Sudden failures are not UOA "material" of course - I had two faulty camshafts fail under Warranty - these were between used oil analysis (some excessive metal was evident in the emergency used oil analysis) but the failures were detected in the "old fashioned" way - by exhaust sound. I also had two turbochargers fail under Warranty and not detected by used oil analysis of course

Gradual excessive wear such as some bearing "issues" and etc may be able to be detected but you need to be experienced in reading and interpreting the sometimes obscure signs

Failure to respond to negative indicators in used oil analysis (such as excessive glycol) will likely result in engine failure. This was the case in one Client's vehicle where the Service Manager failed to act. The engine Manufacturer would not cover under Warranty, the Oil Company correctly blamed the Service Manager. The Owner blamed the oil. Of course it was a leaking liner seal! The Fleet Owner paid the $20000 bill!

Jim Allen - Hi Jim. Like you I think windage plays a real role and contributes to the oxidation rate. In high speed heavy diesels the application places the engine in various locations and mounting angles. This means changes in sump configuration and of course oil level and capacity. I agree with you on design contraints too and have had other engines where the operating oil level had a distinct affect on oil consumption and degradation

 

[Jim Allen]

Originally Posted By: Doug Hillary

Jim Allen - Hi Jim. Like you I think windage plays a real role and contributes to the oxidation rate. In high speed heavy diesels the application places the engine in various locations and mounting angles. This means changes in sump configuration and of course oil level and capacity. I agree with you on design contraints too and have had other engines where the operating oil level had a distinct affect on oil consumption and degradation


I currently have two diesels where this is true, both "old school," a 6.9L Ford/IH IDI and a Neuss D358 in an IH tractor. They like to be midway beteen A and F, in theory a quart low (add mark calls for 2 quarts). Have had engine in the past where this was true also, a 413 Chrysler V8, a 230ci L-head Dodge six and an A-Series BMC in a Spridget.

I'm not sure if windage vs oxidation has ever been discussed here (that I recall). Observation will answer the level vs consumption questions for any engine. My newer gas engines (3.0L Honda V6 and 5.4L Ford V8) don't seem to mind staying at the full line. Neither uses more than a few drops of oil between 7500 mile changes (no apparent change in level, but I don't know about oxidation. Haven't tested to Ford oil at all yet but and haven't had the Honda tested in that way.

 

[XS650]

Jim, I had a discussion with a Mobil engineer about oil temperature about 16 years ago when I was involved in a vehicle development program.

He said that windage had a significant effect on oxidation rate.

 

[Doug Hillary]

Hi,
Jim Allen - Yes the BMC "A" suffered from this - depending on vehicle application as I recall (the "A" was a popular engine family as you know)

I am very familiar with The IH Neuss D358 (from Neuss in Germany). Again vehicle application specific too - some disliked what they called the "throwaway" engine. In various fleets here however they were great performers when looked after correctly - I agree that windage was an issue here again (causing oxidation) and regular OCIs in road vehicles cured a lot of ills. I saw many of these engine heavily "coked" up through poor quality lubricants and a lack of maintenance - the turbo version which was available here (DT358) especially IIRC

 

[REDDOG]

Hi all,

Thanks all for the great discussion. I have heard of oil churning secondary to overfilling, but I had never thought much about windage being a factor in a "factory" set up. I will certainly give it more consideration in the future!

Thank you all again, excellent points!

REDDOG

 

[Jim Allen]

Originally Posted By: Doug Hillary
I am very familiar with The IH Neuss D358 (from Neuss in Germany). Again vehicle application specific too - some disliked what they called the "throwaway" engine. In various fleets here however they were great performers when looked after correctly - I agree that windage was an issue here again (causing oxidation) and regular OCIs in road vehicles cured a lot of ills. I saw many of these engine heavily "coked" up through poor quality lubricants and a lack of maintenance - the turbo version which was available here (DT358) especially IIRC


Interesting comments on the Neuss. I haven't seen many in OTR trucks here in the USA (they were used in medium duty trucks), but they were common in IH tractors and combines into the '80s. In that realm, they are not considered "throwaways" but not as highly regarded as the bigger, more powerfull American made engines. My 826, for example, was marketed as a "budget" tractor, essentiall built by taking an 856 and replacing the Yankee-built D407 with the Neuss D358 and making a bunch of normally standard features optional. That gave people the impression of a "lesser" engine, but I don't think it was, really. Smaller and somewhat less powerful, but not junk.

My D358 has 8300 hours and, AFAIK, is all original. Still runs well. It's a very low compression DI diesel, so is prone to "wet stacking" (notoriously so) when the whip isn't cracked hard enough to get combustion temps up. When I first bought the tractor, it used 6 or 7 quarts of oil that first season on a fresh change of Case/IH SAE 30 (recommended by the PO). Buyer's remorse big-time! I learned several things: don't let it idle much, work it hard and I changed to a 15W40 oil. I didn't have that oil from the first season analyzed but it reeked of diesel fuel, so I suspect fuel dilution was a part of the oil consumption problem. The next season, oil consumption was cut in half and the oil analysis came out surprisingly excellent for such a high time engine. The season after that, my oil consumption had slowed to 1-2 quarts per season. This last season, about 55 hours IIRC, it was only one quart. I'm not sure I understand all the reasons why this occurred.... but I'll take it! I give some credit to 15W40 Rotella-T and some to the new operating parameters instituted. The engine is VERY fuel efficient, using about 4 gallons an hour pulling a 9-shank chisel plow 8 inches deep in Ohio clay (that works out to about 80 percent power, which is about all the power the available traction can support most times). My neighbor has a similar class tractor (a John Deere 4020) and uses 2 GPH more with the same type of chisel.

 

[Doug Hillary]

Hi,
Jim Allen - Great to hear about your Neuss! I was always a fan of these under appreciated engines (much like the IH DT466 was in its earlier life in the '70s etc), many of my Clients purchased them (under my direction) for use in city and near rural delivery situations
They were reliable and sound performers when given the correct care and attention and worked as they like best!

Many are still around and still going well!

 

[Jim Allen]

Doug, and other interested parties, I think I'll start a new thread on windage, oxidation and oil consumption in case you'd like to partake.