Club 80-90 Forums

Hope some find this interesting:

http://home.stny.rr.com/jbplock/ISO5011/SPICER.htm

Testing of different brands and kinds of filters for GM Duramax diesel. I found it interesting how much flow and how well a good paper filter is compared to gauze filters.

They are flowing 350 cubic feet per minute.. That's alot of air and only show 1.69 inches of water difference in resistance. 27.71 inches of water is 1 psi... so 1.69 inches isn't much vacuum/pressure difference on intake.

Looks like stock is best again. (ish)

Some people have a great deal of free time.

Having a lull in work. It's either feast or famine. Looks like in another week or two it will be 12 hours days.

lloyd wrote:Having a lull in work. It's either feast or famine. Looks like in another week or two it will be 12 hours days.

I wasnt meaning you lloyd, please forgive me, I meant the people who wrote that report.

I am on a day off and have been on and off all day, bloody adictive.

No offence taken. But truth is truth. I have had extra free time.
Do know what you mean about addictive.
As for report, at least it wasn't funded by tax monies.

would love to get the van on a rolling road and check out the stock Man filter against the 100k km one and the K and N alternative to see if any difference

Would be nice to know. Might be nice to try no filter as well. My experience says difference would be minimal on clean filters. Never tested a well used one. Butt-dyno has felt a difference when replacing a really dirty filter with a new one, but couldn't tell any with normal 20k filter change.. most times it's a complete tune-up when I change filter so not applicable.

Got a K&N on my landy as the original oil bath has too smaller pipe for the retrofitted diesel and the corect oil bath for the diesel doesn't fit under the bonnet. Made it noticeably more lively but you really pay the price with induction noise (its a noisy engine anyway, so to be compaining about the induction noise is saying something!). Thats just a pancake K&N on the end of a pipe so about as simple as you can get, but I think as far as filtering goes its alot better than nothing but not a great filter, prone to inhaleing water too. Great for a [road] race engine with short life but not so suited to other things especally off road machines. If anything else fitted easilly it'd go, I keep thinking about replacements (procides which its really dirty and needs cleaning - probubly about 75k miles less than they claim it'll need a service at!

In an original houseing like the JX one they might be better, especally with a cyclone, but for genral use I think the normal paper setup takes some beating all round, nothing will make it significantly more powerful. Better to just turn the turbo up if you want more air and change the filters more, not expencive.

I've herd oil baths are about as gooder filters as you can get but they are a bit restrictive. badly mounted you could get the oil into the engine but its very rare - Land-Rovers had oil baths untill the 80's (when they went cheeper with paper) and I've never herd of a diesel drinking the filter oil when the filter is properly clamped in place, even when being rolled.

Thanks for posting that, very interesting. Would like to put that link in the Wiki , or the whole article. Any chance you find out if that'd be OK Lloyd? Nice to get the nod, as that's a fairly definitive set of comparative tests.. although I don't see a detailed description of each of the filters or a really throrough post analysis summary. Some would say it speaks for itself I suppose, but it's normal to appraise the results in synopsis form somewhere in a report.

I've stuck with stock JX paper element, for a few reasons, laziness being one!

On recent trip in very dusty conditions in Pyrenees, changed filter once and cleaned 2nd one out 2 or 3 times.. totally packed with fine yellow/white dust.
Following what i do with my workshop jetvac (same element for 5 years, till it fell apart eventually, then replaced a year ago)
First I knock it out against a tree or with a stick, until it stops producing a cloud of dust (up to 5 minutes), then I brush it out vigorously with a proper bristle hand brush (dustpan and brush size).
Then was blowing up and down each fold-line with my Michelin 12V pump/compressor... and still getting dust out.

Also emptying vortex/Cyclone end-cap.

Another incident worth mentioning, is a blowing exhaust manifold... as the fumes at that time could recirculate back into the n/s Doka tunnel (not now!), it was blackened and blocked to the extent of at least 1 mpg, maybe 2 mpg... I definitely saw the change on my consumption graph, and definitely noticed the better breathing when replaced, like a breath of fresh-air.. I knew soemthing was up but hadn't occurred to me for a while after to check the filter - Duh!

Now, on this year's trip, PeteP was behind me most of the time, sitting in a wicked dust trail for hours every day. He has routed his air pickup back into the locker and thence through a 'massive' air filter from an industrial diesel that Pete M gave him... this takes two filter elements, an inner and outer, PeteP only had the outer fitted (seemed like a wire-braced synthetic paper/fabric) element, but didn't seem to get dirty at all...

I'm thinking of keeping my JX filter but routing the air intake into the locker,there's a mod Pete P has done to the box section beam alog the top that allows air to come down from the cab louvres behind the back window... I think!

JX filters from GSF; £12 if you get a good discount

Conclusion... JX paper is good in normal road conditions (would now change 'on condition', which could be a year or two, could be a week or two or a day in bad conditions.. that's the reality I think. But protects well!

But as those test show clearly, at high flow rates (turbo diesels) and high contaminant air source, anything will block sooner or later - a good big area corrugated paper one later and smaller one earlier... so anything you can do to source less dirty air is very important when driving in clouds of fine dust. A cyclone or vortex pre-filter is also a good first-line defence mechanism! Even two!

And dry tracks are full of fine dust, presumably some soils worse than others.

Always heard good reports of oil bath filters, used to have them on a lot of cars, don't see them much now... for obvious reasons!

HarryMann wrote:I've stuck with stock JX paper element, for a few reasons, laziness being one!

On recent trip in very dusty conditions in Pyrenees, changed filter once and cleaned 2nd one out 2 or 3 times.. totally packed with fine yellow/white dust.
Following what i do with my workshop jetvac (same element for 5 years, till it fell apart eventually, then replaced a year ago)
First I knock it out against a tree or with a stick, until it stops producing a cloud of dust (up to 5 minutes), then I brush it out vigorously with a proper bristle hand brush (dustpan and brush size).
Then was blowing up and down each fold-line with my Michelin 12V pump/compressor... and still getting dust out.

JX filters from GSF; £12 if you get a good discount

Is all that worth it for £12?

Another incident worth mentioning, is a blowing exhaust manifold... as the fumes at that time could recirculate back into the n/s Doka tunnel (not now!), it was blackened and blocked to the extent of at least 1 mpg, maybe 2 mpg... I definitely saw the change on my consumption graph, and definitely noticed the better breathing when replaced, like a breath of fresh-air.. I knew soemthing was up but hadn't occurred to me for a while after to check the filter - Duh!

Do you think the performance drop was from gas recerc or just a blowing exhaust? My Dads landy has a crossdraft engine that ocasionly decides to eat manifold gasgets, the last one dropped perfomance so much it struggled do do 45mph in 4th when it usally will do 60 in overdrive. Gasses geting back into the engine in that case I'd have thought very unlikely but the turbulance caused at the leak probubly did a good job of chokeing the manifold?

Conclusion... JX paper is good in normal road conditions (would now change 'on condition', which could be a year or two, could be a week or two or a day in bad conditions.. that's the reality I think. But protects well!

Service instructions of a 50's landy recomends washing the gauze with petrol and changing the oil in the bath every 6 months or so, but warns depending on enviroment up to twice dayly could be required! Bet none got that pampered in real life! (also recomends removing the ignition key when parked for anti theft, a different world back then)

so anything you can do to source less dirty air is very important when driving in clouds of fine dust. A cyclone or vortex pre-filter is also a good first-line defence mechanism! Even two!

Another plus to the snorkel, why you see them even on cars in desert enviroments. In the UK its hard to think past their use beond modern defenders/discos, usally just for styleing.

Always heard good reports of oil bath filters, used to have them on a lot of cars, don't see them much now... for obvious reasons!

Only really high manufacturing cost and a bit of efficency thats killed them off, probubly not so easy to get emissions down. I've herd you still get them on alot of plant as they are dam affective. Serviceing is cheeper as they don't require parts, great for remote locations.

Is all that worth it for £12?

Yes, when you don't have a 2nd spare up in the middle of the Pyrenees !

I meant the comparison of performance and mpg was after manifold leak was fixed, but have also now completely sealed tunnel compartment/cold air box fed by side louvres.

Maybe another thing influencing oil bath, is there's no serviceable items to sell parts for, stuff like filters must be a good revenue earner.

For the record, this was post engine rebuild, new head, rings, honed but not rebored etc. just before Coast to Coast for next 5,000 miles.
Dirty filter was found blocked badly a round 2650 mile point
Some heavy towing approaching 5,000 miles... alwasy knobblies, lots of off-road in there too..



The black running mean is the one to really look at, easy to do in Excel

I'll try and get ahold of someone, but don't hold your breath. Think I originally found this info on one of the GM Duramax forum website. It was a couple of members of the forum that coordinated and had the test done. Diesel pickups in USA/Canada are very popular for pulling heavy trailers... and some are quite powerful.

All filters were replacements for OEM filter into OEM filter box.