Correct oil filter!

[Guy Croft]

A seemingly simple thread that has developed into a rather interesting one - unfortunately unlike Sandro Pino who designs spark plugs - we don't have a commercial oil filter designer in the membership - as far as I know..!

Homme has remarked that "oil filters are very good at filtering out particles that are larger than 40-50 micrometer. However, the smaller ones will pass through". I may a bit out of date on this but my understanding is the minimum particle size the filters are designed to capture in our engines is much smaller than that - probably about 15 microns (micrometers). In case you don't know one micron is 1/1000 of a millimeter or 1/1000000 of a meter. That is a practical and achieveable limit without massive cost implications. Now the oil film thickness on the big end journal at max loading can fall maybe as low as 2 microns thick. I took that from a Ricardo test on a big diesel - there isn't a lot published about this. That is a pretty thin film so naturally one wonders how much untrapped debris there is likely to be in the oil in the 2-15 micron range? I guess the answer is not much or engines would not last very long. Most of the debris must be bigger than that. Racecar filters are available from companies like Canton Mecca in the USA that, according to the them can fiter as small as 8 micron. They are beautiful filters but extremely expensive in comparison with OEM types. No doubt there are others.

Commercial filters are (or certainly used to be) selected according to the % particle size entrapment they can cope with during their service life cycle. There will be a set of criteria I imagine that calls for a certain percentage of large and small particles in the critical 15 micron + range that they must cope with before being selected for introduction.

I think it's important to be balanced about oil filters. An engine that is a very clean build (and I consider this to be of paramount importance) and which is correctly calibrated and fitted with a good air filter - will generate almost no metallic or other particle debris of any kind during use. Apart from a tiny amount of material during the bedding-in phase, depended, again, on how good the build is. A rough honing job will certainly generate plenty! An engine that uses a measurable amount of oil between changes has worn internals and plenty of debris will go into the filter. But an engine with very low oil consumption (provided a sensible oil-change routine is followed) will have an oil filter that will come off almost as clean as it went on. Though that said everything wears over time and as the engine gets older the demand on the filter will increase, but the better built engine will wear far more slowly, if you follow my logic..

Bypass valves - I have no doubt that on pretty-well every engine I ever have built the canister filter bypass valve will have opened at some time (eg: very cold start accompanied by sudden high rpm & very high pressure in the filter) allowing unfiltered oil to circulate around the engine. But at the same time I have no great concern over this. I have never heard of a consequential failuer and why should there be one? All the oil in the sump has already been thru the filter and the only possible source of contamination is some external line or accessory that has been introduced latterly and which is not clean, or some new contaminant introduced into the sump. I've only really ever used canister filters and they pretty-well all have had bypass valves. And I have used them on all my dry-sump systems too and they really do shove out high pressure on cold start. I have no criticisms to offer of any of the following and have used them routinely: Mahle, Fram, Champion, Purolator, Motaquip to name but a few. And if they are of genuine OE supply they are certainly good enough for us, I have stripped many, many TC Fiat units with well-over 150,000miles use on them and found crank and bearings in 'mint' condition. You don't get that if the filtration is under-par.

GC

[twincamspit]

All the oil in the sump has already been thru the filter

Now there's a good point that had totally bypassed my tired mind! Thanks Guy.
I'm now less concerned about the non-'standard' rating of the bypass valve in the smaller filter.

[WhizzMan]

Guy is right, i had my microns in silica particles wrong. Any silica particle between 1 and 5-10 micron will give you wear on your piston rings. The value of 40 microns stuck in my head, because that's the largest size particle a lot of full flow filters tend to filter fully effectively. Anything smaller and they'll let some of the particles pass.

I've been doing some reading, and it appears that there are several standards for effectiveness and size of particles filtered by oil filters.

Getting filters that are filtering anything bigger than 5 micron or even less, is not that easy for older cars, but you can find them. Especially for older cars, these don't seem to be the "manufacturers standard" at all times, so you may have to check actual specifications of the manufacturer and the aftermarket producer. 1 micron filters are harder to find, but they do exist as well.

The "micron" specification is not really a standard and any manufacturer may use their own method to classify their product. It seems that typical paper filters that are rated "10 micron" will only filter 40% of all particles in the 10 micron range, so be aware that a filter that only has a micron rating (and nothing else), may not be as effective as it suggests.

There's also a "beta ratio" number, that essentially means that the higher the number the better the filter. Anything over 75 is generally considered good. There beta number is derived from a multi-pass repeatable test, that is vendor-independent and specified in SAE J1858. If a filter that is classified as 3 micron, Beta 200, it will filter out 99.5% of all particles that are 3 micron or bigger.

With this new found knowledge, I'll be much more careful in purchasing oil filters. I tend to travel a lot and I like to keep my cars until well after they've lost economic value, so anything to increase the life span of my engines significantly, has my attention. From what I gather, Mann filters that use polyester fleece seem to be able to get 75 beta at 1-3 micron and do even better at bigger particles. There must be other brands too, but it's hard to find data.

Regarding Purolator, It appears they are (also?) reselling various other brands, including Mann. It could very well be that the filters they resell are made custom for them, to their specification, but it seems they have stopped manufacturing, at least for several models.

[timinator]

This has been an interesting thread. Just like to add some ideas. I like to use 2 quart non-bypassing oil filters. To do this it is required to increase the size of the bypass channel in the oil pump. Then remove any pressure relief valve and plug the channel. The advantage to this is no unfiltered oil. Most of my filter catalogs give a nominal rating to this style of filter at 15 microns. Most of the standard OEM filters are at 22-25 microns. Filters at 8 microns or less are generally in the hydraulic machinery or power transmission category.

After every race week the oil filter is removed and cut open. I use a Champion CT 470 filter cutter as it makes a clean cut and does not put any shavings into the filter. If there are no significant amounts of metal in the filter element I put on a new filter and top off the oil level. It is much cheaper to use good oil and just top it off than to do a complete oil and filter change after every race. At the end of the season the oil still looks new.

The Beta 200 ratio actually means that if there are say 2000 particles of a certain size or larger upstream of the filter then downstream there will only be 10 particles of that size or larger. It does not mean there will be zero particles of that size or larger. There is also little information as to the total amount of particles a filter can hold. So changing filters often is reasonable.

Tim

[Guy Croft]

Do you have a photo of this 2qt filter monster?

G

[WhizzMan]

Filters at 8 microns or less are generally in the hydraulic machinery or power transmission category.

It appears those filters are being used in the "extended service" intervals of modern cars as well. Long life oil of high quality, combined with synthetic ultra fine filters seem to do the trick.

Doing only a visual inspection of oil quality can be misleading. Most of the damaging stuff can't be seen because it's too small, or because it's a chemical compound that's not in the right quantity in your oil. It could very well be that your filter and oil are fine, but I'd spend some money and send a sample off to verify that just in case, if it was my car.

[timinator]

This is one of several I use. Baldwin B-7, AC PF932, Fram PH373 to name a few. It can present a problem in trying to remote mount due to size. On a small block Chevy with a deep oil pan it just fits.

Tim

2qt. Filter

filter.jpg (97.46 KiB) Viewed 9191 times

[Guy Croft]

Now I understand, big Chevy unit..

G

[timinator]

Just to be clear, I was not implying that there are any non-bypassing filters that will thread on a 130TC. The largest filter that I believe will thread on without hanging below the oil pan is a Fram PH5100 or Baldwin BD232 which are 144mm. tall. They have a bypass pressure of 36 psi and an anti drain back valve.

The idea of using a non-bypassing filter involves making it work by whatever means. Since these filters have to be big enough to handle 100% of the oil pump output they are large. Creating bits and pieces to adapt things has always been part of my business. I enjoy doing it and hope others do to.

Tim

[Urbancamo]

There was some in-depth oil filter comparison couple years ago in my country's leading automotive magazine called Tekniikan Maailma (World of Technology). Of course I cannot publish this, because it's copyrighted material.

They tested 15 different brand filters for Volvo cars. Why Volvo? Because Volvo has used this same filter for decades.

Filters were tested in laboratory using ISO 4548-12 test method (google for it)
There was pretty huge differerences. They tested their filtering ability in 20-50 micron range and made a graph for it. They also tested their dirt capacity.
They also opened the filters and inspected the internals. There was pretty big differecens in filtering area, biggest filtering area was in Volvo filters, 19 dm² and smallest was in some Chinese made filter which had only 10 dm² of filtering area.
If this isn't enough, they tested also every filters burst pressure (which was in 16 bar range for every filter) and also inspected the pressure difference when by-pass valves start to open.

Top-three filters were wery close to each other and two of them were made in the same factory line.

Volvo Oe oil filter (Small).jpg (39.07 KiB) Viewed 9164 times

This is my choise for Fiat Twin Cam, Lada SOHC engine and of course most Volvos today. It costs 6,90 €uro, comes from reputable manufacturer (MANN) and it's easily available. I don't sacrife any more thoughts for this.

My team member has an old 740 Volvo petrol, which has done over 625.000 kms. It has flawless service history. Oil change interwals had been 10.000 - 20.000 km range depending on interest and driving. Oil consumption is negligible. Oil used has been synthetic 5W-40 far as I know. It has a similar top end like Fiat TC, with buckets and shims. When i last saw the camshaft, it looked like brand new...

T

[Guy Croft]

yes, Tommi,

Volvo - like some other manufacturers a byword for reliability.

Just goes to show how high some European car mfr standards are really which reinforces the point I made earlier about OEM supply or big name equivalents usually being 'good enough'.

G

[Urbancamo]

You're absolutely right Guy.

And one part I forgot. They collected used OE Volvo oil filters on Volvo services. They were used 15.000 kms which is regular service interval.
Every filter had still filtering ability left and they were not near of clogging this point. But they don't recommended longer service interwall with these "regular" oil filters.

With today's oils and filters you're engine is gonna be very long-lived. In the 70's regular engine job interwall was 100.000 kms or less. Nowadays car scrapyards will mainly send engines straight to steel recycling. There is absolutely no market for modern used engines.

T

[Guy Croft]

when you say:

"There is absolutely no market for modern used engines.."

you may not realise what in interesting and significant point you have made.

I think that and the issue of parts availability for engines used for competition (going as far back as the 70s +) is worthy of a thread on its own. I have to admit we have terrible trouble 'sourcing' (ie: finding) the most basic things that 10 years ago you could walk in and buy no bother at all. Some recent examples: it took me an hour to find a set of HT leads the other day for Mick Woods Gp4 16v because no-one round here stocks HT leads in racks where you can just pick the ones you want. Same applies with hose - story is always 'we can order it for you' I want it today not tomorrow! Could not trace my Snap-On agent via the web had to ring former agent Dave Harper for the customer service phone number. Every time I order oil filters the make has changed, no doubt because some purchasing 'professional' at head office has worked out the margin is better with a batch from brand A rather than B. Things like that never matter to GCRE - we just need it fast.

Poor us, specialists out on a limb. And as the days go by I realise how incredibly specialised we have become - simply because there are so few of use left. Everything is geared up for 'fast-moving' 'big margin' 'boxed sets' 'sold by part number' 'computer listed'. And many times the ordinarily able assistant on the end of the phone won't have a 'blind clue' what I'm talking about.

I am shocked too at how the quality of equipment you can routinely buy in auto retail outlets has deteriorated and how the choice of what you can buy has diminished. If it's oil the sky is the limit, every brand you could wish for but a 3 year old could sell oil. If it's something complicated like cable connectors or hose clips that's another matter. Every wretched thing is made in the Far East and about as 'fit for purpose' (in terms of longevity which is paramount with tools in a pro workshop) as a coffee mug with a hole in it.

I dread the day when I phone any of our 10 1st tier suppliers for anything from belts to clutches and the line is dead. That really will be the end of it all and will the world be a better place? Will it heck.

GC


G

[turbofiat]

Somebody wrote: "There is absolutely no market for modern used engines.."


Here in the United States that is not true. I know a local Honda mechanic who installs used engines imported from Japan. They come in on skids wrapped in shrink wrap from some importer from Florida. These engines come from Japan and have as little as 50,000 miles on them.

I asked him what was that all about. He says in Japan engines have to be replaced every 50,000 miles either for emision reasons or because there are no junkyards because the island is so small. He said it was far much cheaper to install a used engine with 50,000 miles on it rather than to rebuild it.

While in the UK back around 2000, a friend told me there was a market in the UK for X-Japanese SUVs called the Shogun or something or another that have too many miles on them to be emmision legal in Japan. I think the Shogun is the same thing as the Mitsubishi Montero sold here and Pajero in other countries. Same deal with RHD vehicles being imported to the eastern coast of Siberia. Because it's cheaper to import used cars from Japan than all the way from the other end of Russia. You get the idea.

Here in the United States it is not uncommon to find 10 year old used cars with 150,000 to 250,000 miles on them. Often times if the engine fails, the cost of just rebuilding it far outweighs the value of the car.

For example. A friend had a 95 Saab 900 with a rod knocking. The dealership wanted $5000 to rebuild the engine. But the value of the car was around $2500. But a $1500 used engine from a wrecked car was an option. I can't remember what he did with the car. Wheather he had it fixed or he sent it to the junkyard. So there are actually "nice" cars in junkyards with bad engines or bad automatic transmissions. Tons of Land Rovers for some odd reason.

I say automatics because they have a much higher failure rate than manual transmissions. Especially anything with a Mitsubishi drivetrain like those old Chyrsler minivans. Dad's 94 Plymouth went through three transmissions then finally went to the scraper. The ones still on the roads are the ones made back in the 1980s installed with the Chyrsler 2.2 four bangers!

[Guy Croft]

You in USA are spared EU regulations regarding scrappage and a million other things!
Here it is a very different story.

G