It is not physically possible that a ramflo is the same as running no filter.

1) the thing has a gauze mesh over it that is proven to be restrictive. It's not even fine mesh it's enormous with small holes
2) the overall filter media is nowhere near adequate size
3) there is a outer clip, and an inner plastic gaurd that restricts flow even more
4) there's a 2 inch Ramflo badge on the mesh to even further restrict air
5) the backplate has a 3-4mm lip around the filter element to even further restrict airflow

All I know is as soon as I pop a ramflo on my car, the jetting drops 4 steps and is still running rich.

I am not sure what the circumstances of the dyno testing where like if you changed jetting to compensate for running lean situation without the filter, but I can assure it it physically CANNOT add up that ramflos are the same as running no filter. Unifilter element or otherise.

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Lillee - 1969 Morris Mini K

Ask GR, he was there, you were not, the Ramflo/Unifilter made no difference. To either the HP, or the A/F ratio.
It might be different on your motor, which is NOT using the same manifold or head as mine.

We then fitted an HS6 on an RE7 manifold and no filter, it lost 0.4HP (but gained in midrange torque).

Anyway this thread has got off track, we now return you to our regular K&N filter programming.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

OK I'll be good. *goes back into cave*

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Lillee - 1969 Morris Mini K

sure, they filter down to micron size, I guess all air cleaners filter down to micron size... but how many microns??

my local engine reco shop has seen engines wrecked in 500k's due to the owner taking out the standard fillter and putting in a K&N

read this for a good example of a scientific test comparison...

http://forums.nicoclub.com/debunking-th ... 80100.html




I've been using oiled unifilters for a while, and I'm over it - I'm going back to paper...

Graham Russell ran his 1400 for 8 years, 50,000miles with no filter and only tore it down recently to rebuild it for ponies. It still doesn't run any filter.

"What filter should I run Graham?"
"None"
"What? no way"
"Ok run one if you must"



Honestly as long as large rocks don't go in there, it will only wear your valve seats and rings which are bound to wear anyway, just quicker. Rebuild after 50,000 miles, in my case that will take about 20 years to reach anywhere near 50,000...

But yeah I am not saying don't run one, just food for thought.

NB. I run a filter with no oil

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Lillee - 1969 Morris Mini K

Rubbish surely, there's got to be more of the story to it than that, like he drove Paris to Dakar with the car or something, or it was a poorly build engine to begin with. I've heard about engines coming back after 20miles but nothing to do with filters...

100's of engines have been run in and power tuned on GR's engine dyno with no filter on with no detrimental effect. Sure it's in a dyno room but it's still unfiltered air. If you're saying that a few microns of dirt can ruin an engine in 500 miles then running unfiltered air should ruin it in no time flat << which isn't the case.

Anyway I don't mean to start a post war, but that article states that 7.0 grams of dirt was passed through on the K&N as apposed to 0.4grams... staggering and mind blowing except that what it fails to scientifically test is how long the engine sucking only 0.4g of dirt will last compared to the 7.0g dirt engine if all things were equal. I doubt ANYONE has hard data on this.

And if they did, I bet my bottom dollar that it equates to very little. It's then a trade off of power and performance at the sacrifice of engine longevity. Oh Wait! Isn't that what a performance engine is all about? I bet a turbo will wear the engine faster than 7.0grams of dirt! /end rant, going to eat lunch now

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Lillee - 1969 Morris Mini K

Most commercially available filters, stock paper types, K & N, Unifilter, Ramfo etc etc are quite good for most normal and track use.

However you cannot consider or look at the filter in isolation.

Mant Air Intake Systems are let down in terms of filteration not because of the filter element itself but because of an over-looked or inadvertant 'leak' past the filter and in fact the better the filter element works the harder you need to look for and consider these 'leaks' because as the filter starts to do it's job, the pressure drop across it will increase and so too will the pressure drop across any weak points in the inlet system.

One very simple and often overlooked example is the hole in the centre of the wing nuts that hold the standard filter cases on.

The other place that is often overlooked is the crankcase breathers.

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the two examples he gave me were of a Falcon that was driven along a dirt road for a couple of k's each day and wore out in 500k's - prior to fitting that filter it had been a good reliable engine. The other was a Speedway Sprintcar that needed re-ringing after every race weekend, and after changing to a paper filter (no real performance drop) it was lasting a whole season

Like I said in my first post, if the car is going to be driven on dirt, it needs a filter that actually filters. If it's a road car around Sydney, maybe not such a big deal, but run your finger along the top of the crossmember, you'll be surprised how much junk collects there

I have built rally motors for RWD VWs years ago, NO WAY would I run a road motor as a daily driver without a filter.
I've seen a 1600 VW motor wear the rings and bores out in 1500 miles.

Even my supposedly POS Ramflo/Unifilter (oiled) filters out a surprising amount after 5000 miles of city driving. It's way better than nothing.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Not exactly filters but to get an idea what can be in the air in city driving - years ago I had a Pharmacy on a road with a tram line going past the door - the shop girls spent all their spare time dusting shelves and stock to keep the place clean - it wasn't until the tammies went on strike for 2 weeks that we realised the black dirt collecting on every thing was rust off the tram lines as in the 2 week period there was literately no dirt on the shelves

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David L


My greatest fear in life is that when I die my wife will sell my Mini and tools for the price I told her I paid for them!

Simon, many thanks for the link, I had not seen it before.

There's a version with more details (inc test data, here : http://www.billswebspace.com/AirFilterTest.htm)

It certainly challenged my long held belief that K&Ns were quite efficient filters, better than paper at times I thought. I'm very surprised by the performance of the AC delco part, it way surpasses a lot of the other paper elements - what the hell is it made of??

Another (not so rigorously done) test done here : http://www.bobistheoilguy.com/airfilter/airtest3.htm

Still shows paper as the superior medium, but not to the extent of the other test. Foam does not do well there.

No filter? No way! Just because the air looks "clean" does not mean it is!

cheers

Jacob

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'72 Clubman Van - 1022cc, 295 head, 731 cam - Daily Driver
'69 Morris 1100 S - Dinged by a bus, in shed under repair
'64 Morris 1100 - Early 1100, long term project

Just out of curiosity... has anyone taken into account how much the K&N filters were oiled? if at all..? Figures/charts/graphs/experiences with these filters mean nothing without all the variables to go by.

There's a direct correlation to filtration vs flow when it comes to the K&N filters. More oil, less flow but better filtering and vice versa.

My experience with stock paper and Unifilter (oiled) elements - had an XD Falcon, unmodified 250 cross-flow auto in the Pilbara in late 80's. Did lots of runs to places like Marble Bar, Port Hedland, Wittenoom, Geraldton & Perth. Lots of dirt roads and single lane sealed roads, lots of dust around, the white Falcon ended with the Pilbara red tinge.
With the stock paper filter, there was always a very light smear of dust film inside the filter case, around the carby mouth. Was the same regardles of the brand of paper element. It bothered me so replaced the paper element with a green Unifilter oiled element. After that, no dust film whatsoever. The filter case was clean as. Sold me on oiled elements and have used K&N filters for the last 20 years without any bother. Oiled elements must be kept oiled to work properly.

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Steve