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MG Midget and Sprite General - Alternatives to K&N?

Hi everyone

Time for an air cleaner clean out, so I whipped it off and look what's inside

This is the pipe the filter sits on the end of

It is BEHIND the filter. So it should be clean, no?

Next post will have a picture of the back of the throttle body, also not clean.

Now, is this because the (2nd hand) K&N has got a bit old, or because of where I have it (down behind the hole in the front drivers side splash guard)?

Is there anything that will cope down there, or do I need to rethink the air inlet plumbing before I have a 1.8 with 1.4 pistons rattling around in it....

either way I'm not particularly pleased, it's supposed to filter. Which it's clearly not been doing.

Rob Armstrong

Back of the throttle body.

P.S it's a K series if you've not noticed :p

Going to clean it up properly and put it back on, as there's no other alternative at the moment and I don;t really feel like buying another one..

then think about something to try and make it better.



Rob Armstrong

Paper element should work better but needs changing more often
Onno K

How about a picture of the K&N and case?
Daniel Thirteen-Twelve

no case on it, it was just straight in the airflow at the front there. I've washed an awful lot of cr*p out of it, but didn't take a picture of it before I cleaned it, which was a bit silly.

Wonder if it got wet down there and washed its own oil out?

It may well be that the mounting location is too fierce for it.
Rob Armstrong

p.p.s it's the K-series in the midget, so no 'standard' setup :)
Rob Armstrong

is the filter a cone type that jubilee clips to a trunking? (57i style?)

how has the filter been cleaned and what with

a photo of the filter from inside and out would be useful

I've had a couple of cars with a K&N fitted very low at the very front middle of the cars
Nigel Atkins

Cone type, Jubilee clips to drainpipe, and was a 2nd hand 57i filter.

When I got it it looked OK and was still oily and red, I stuck it on and forgot about it.

Some pics of it 'naked' without any oil, but after cleaning. I couldn't get it any cleaner than that.

I can see a few pin holes in it, but it's not re-oiled yet. It's drying on a radiator. The metal bit fell off the end while I was washing it, but it's still sealed.

Pic of outside:



Rob Armstrong

Pic of inside



Rob Armstrong

pic of light coming through from outside



Rob Armstrong

better pic of inside

looks like a hole in the bottom but it's a reflection

Rob Armstrong

Probably the flash off your camera has made the inside of the filter look blue white ultra clean

What did you clean it with and how?

The outside, allowing for the fact its a photo, then being viewed on a monitor, well it looks awful and very dirty

Does the stuff you’ve found on the pipe and throttle body appear to be cotton(?) dust off the inside of the filter?

Also is the filter big enough for the HP of your car (1.4?)and that pipe looks like a funnel or is that just the photo, have you another photo of that pipe from the side?
Nigel Atkins

Nigel,

How is it that you often/frequently say, you are not technical, and yet you ask so many technical questions? :)
Lawrence Slater

Rob,
sorry I missed your last photo as I was typing – lets put it this way, if it was a tea towel would your wife/gf let you use it to dry up the best dinning plates

Lawrence,
never technical, usually just the simplest maths or asking simple stuff like what size is it - if I ever go into a shoe shop I ask for a size and width of shoe suitable for my (small square) feet
Nigel Atkins

>>What did you clean it with and how?<<

K&N cleaning fluid, as per the instructions.

>>The outside, allowing for the fact its a photo, then being viewed on a monitor, well it looks awful and very dirty<<

it's a bit black, but an awful lot cleaner than before

>>Does the stuff you’ve found on the pipe and throttle body appear to be cotton(?) dust off the inside of the filter?<<

looks like very fine dust. Quite a uniform light brown colour, same colour as a completely correct spark plug.

>>Also is the filter big enough for the HP of your car (1.4?)<<

should be, it's certainly not down on power in any way. is the thought behind that that the engine is sucking too hard on it?

>>and that pipe looks like a funnel or is that just the photo<<

It's a 2 1/2 foot length of plastic 65mm drain pipe. Still got the Wickes sticker on it.

G/f says I'd be allowed to dry the dishes with the inside, I'd get a 'look' doing it with the outside.. Though it looks dirtier on the picture than it is in real life.
Rob Armstrong

>>K&N cleaning fluid, as per the instructions<<
I thought you wasn’t one for RTfM - you cleaned from inside out then, not easy with a cone

>>is the thought behind that that the engine is sucking too hard on it?<<
nothing as technical as that :) just if the filter was the correct rate to provide enough air through it

even allowing for a photo that’s not what I’d call a clean filter, I was wondering if the dust was from the filter breaking down, the light brown colour coming from being less dirty inside the filter

my K&Ns have tended to go greyish on the outside with use

you could try emailing K&N UK see what they think to the dust, I wouldn’t show those photos though but I could well be wrong in that

don’t suppose you have a photo of the filter just before you cleaned it?

What colour was the outside before cleaning?

Don’t suppose you live near a chemical or concrete plan, or have any type of dust or chemicals were you store/park your car

my wife gave me some old tea towels for me to use for when I clean my tools or stuff – but sometimes I forget to bring them from the shed and have to be very thorough with the cleaning otherwise I get another addition to the shed tea towel stock

In case you think I’m a clean and tidy enthusiast I’m not more the grubby and now untidy type
Nigel Atkins

my K&N filters after about 20,000 miles use

the colour, again allowing for a photo on a computer monitor and colour of wire mesh rather than filter material

Nigel Atkins

it's not clean by brand new standards, it's a sort of grey colour, like a hoover bag (for people who still have such things)

filter doesn't look like it's broken down, before cleaning it was red and black. Cleaned it with the hosepipe joined to the hot tap, on a low pressure.

no photos just before cleaning unfortunately. And no particularly bad areas near me dust wise. I reckon it's road dirt sprayed up onto the filter then forced through by the air pressure on the front.

A rethink in design of the inlet should sort it out.

I'll RTFM when it's necessary :p I do in fact have all the ones that you keep touting :D *shock!* :p
Rob Armstrong

As stated a few (100's) times on various car web sites: K&N are not very good filters. They may flow very well, but there's a catch (?) to that....
Alex G Matla

Got pic of the thing as installed?

Filter should always be baffled from direct dirt/water impact, makes an incredible difference. Heavy particles fall out when forced to turn sharp corners. Modern filter boxes take air from a clean place, turn it a couple of times with water drains at low points, and typically approach the flat panel from the bottom in a fairly large, hence low velocity plenum. Result is that element is largely self cleaning by vibration.
My 90-94 Mazdas take air from behind the LH side lamp, drop it down with a drained 180 turn which enters the filter box from the bottom; I haven't driven any of them more than 40,000 miles, which gives some crap in the box but paper flat elements are still near new. These elements are only 5.25"x9" feeding 1.6 or 1.8 engines.

But visible pinholes are a fail for sure.

The slower the air velocity (or less the pressure differential) through the element the less crap crawls through, AKA bigger is better.

FRM
FR Millmore

Perhaps other cone owners will join the thread

on my monitor your cleaned filter looks fibre(?) brown with black oily shadows on some parts of the wire mesh – like you stalk dirty diesels

just seen the 65 mm bit, I don’t know, is the filter an adequate size, sounds a bit small to me

as you’re keep it you can monitor the results of the reposition

did I also read somewhere that instead of having a smooth flow of air from a smooth inside of that pipe that a concertina style to disturb(?) the air would be better or was that just a debate

sorry I can’t remember what colour Hoover paper bags were, think Electrolux were yellow(?) I can remember when Hoovers were cloth bags

you used the hot tap in Yorkshire is that allowed and possible

as for the books, as well as owning them you do have to read and reference them :p

I’m up for comparing K&N with other filters if anyone wants to do swap over comparison runs

ETA: typed befor I saw last two posts and 57i came with collar box
Nigel Atkins

Alex,
I'd be happy to find the best filter for my Spridget, I've tried foam on other cars and not liked them
Nigel Atkins

I'm starting to think it's just too much in the horrible air at the front. It sits in the hole in the splash guard where the heater trunking used to attach, I haven't found a picture of it's location, but here it is just over a year / 5000K ago.

It looks like Nigel's have dirtied up less in a much larger mileage. But it's probably not sucking quite as hard as mine :)

Some kind of system is going to get built so the filter doesn't sit right in the airflow. Until then it can sit at the back.

The idea of not having it up at the back there is so it doesn't suck mega hot air.

Rob Armstrong

>>It looks like Nigel's have dirtied up less in a much larger mileage. But it's probably not sucking quite as hard as mine :)<<
how very dare you

is that a bare heater matrix/cooler(?) behind it

oh, and I meant to put before about RTfM it says to let in dry naturally :)

unless your radiator is turned off of course during this mild weather :)

looking at the K&N site yours after cleaning is at the doesn’t need cleaning yet stage

I’ll post links later for whatever is relevant to thread

in the meantime here’s the leaflet from the cleaning/recharge box for others reference - file's too big so here's the link - http://www.knfilters.com/cleaning.htm

for those that don't like reading stuff here a video - http://www.knfilters.com/video/KN_Air_Filter_Cleaning.htm
Nigel Atkins

As I said, ideal is air from a sort of labyrinth into a low velocity plenum, to the bottom of a flat filter. Key here is that that space which eats your tools - between the wing and bulkhead - is your plenum. Dump your cold air in there, and incorporate the filter into a semi sealed diaphragm separating the hot engine compartment air from the cool inlet air. Makes sense to use a modern filter box as the basis for the filter mounting for easy & cheap filter changes. Lots of modern cars have them, but you have different cars to us; most MAF sensors cars have a round hose from the box to the MAF, some of which even have a suitable elbow at one end.

FRM.
FR Millmore

I've had cars that used I think Ford flat panel style boxes with a panel K&N filter fitted inside the panel box with I guess more sucking power than a K :)
Nigel Atkins

You will not have enough air pressure to force particles through. K&Ns filter as well as paper elements. They do work, we have many years under our belts with off road competition vehicles. The K&Ns take water well whereas paper falls apart. If your filter has failed, one is it a cheap K&N copy? Two, was it a proper fit on the plastic pipe, was the material from the plastic pipe? Three, third party damage to filter. Foam filters look good for a while then disintegrate and do not flow as well per sq in as either paper or K&N, foam catches fire well !

Peter
Peter Burgess Tuning

The last pic is mid K- build, so yes that's a naked heater core before being built into the new heater box.

Nice idea using the wing area as a plenum, I'll look into that. Currently that's where the HP fuel filter is living, but I might be able to swap stuff about. There's not a lot of space.

Filter has K&N stamped in the rubber at the end, it was such a good fit on the plastic pipe that I had to really try to get it on there.

Damage to the filter is harder to tell, here's some more pictures (everyone likes pictures) of the outside and the inside:

outside first, taken it in as much natural light as possible, it looks a bit better now it's dried out overnight.

as regards the sizing, the throttle body is 48mm and the original rubbery (and also concertina'd) tubing is also 65mm.

The material inside could be bits of cotton, or it could be dust that's got through the filter, or it could be something else. One thing that is a bit odd is that it hasn't washed out of the pipe, it's like it's statically attracted to the plastic.

Rob Armstrong

close up of the outside

Rob Armstrong

close up of the inside


can see some of the little pin holes I mentioned earlier.



Rob Armstrong

I get the feeling the filter is working, it should work fine when oiled. Could the stuff have been in the pipe already?

Have you experimented on the rolling road with the filter system ? We find bolting a K&N on can lose bhp compared to a standard setup. Extending with pipes seems to lose too.

Peter
Peter Burgess Tuning

pipe was brand new, it's possible that the stuff was in the inside of the filter though., it spent a bit of time knocking about before fitting.

not rolling roaded it at all, and the standard rover setup won't fit.

it goes like nobodies business though. I'd read that straight bolting the free flow filters on sometimes turns out worse, hence the pipe down to the front.

perhaps a good cleanout and refit, then see how it;s doing in another 100 miles might be the way forwards. will definitely look in to having a sort of plenum arrangement as well.
Rob Armstrong

Please forgive the slight thread hijack, although it is relative. I just bought a flat K&N filter to replace the conical K&N replica one I had previously. Reason was, the conical one wouldn't fit with the new stub stack I recently got. So I have a couple of questions.
1. Do I have to oil the brand new filter or do you only oil them after cleaning? Nothing in the fitting instructions about it.
2.Peter mentions that fitting a K&N can sometimes lead to loss of power, so I'm a bit disappointed to learn that.
3. Alex reckons that K&N are not good filters. What do others think?
BTW. it's an HIF44 on an overbored 1098cc engine.(1133cc)

Bernie.
b higginson

'sOK Bernie :p

1) they should come oiled from new. If they're red then they're oiled.
2) K&N straight onto throttle body is normally worse in things like Corsas, as it now sucks hot air. What's needed is cold air or a proper induction kit. And decent filtering. (think that's right!)
3) I'm less convinced that I was, but not unconvinced enough to throw it away and get a different sort. I might try some pleated dry filters on the V8 though.

:)
Rob Armstrong

Hi Bernie

The loss of power is associated with fitment to fuel injection cars where the factory spent an arm and a leg pulse tuning the complete system from start of intake all the way to the end of the exhaust tail pipe.

Brand new filters should be pre-oiled from K&N.

We have never faulted K&N filtration or build quality in the 38 years I have used them.
Peter Burgess Tuning

Peter. Thanks for your prompt and as always concise reply. Thanks also Rob, it's nice to have two people come back so quickly each confirming the other. I feel better already!:)

Bernie.
b higginson

Rob,
on the P6B, I used to get the Mann paper replacement filters and they were so cheap I'd change them twice as often as required

same as regular oil changes the RV8 appreciates clean filters

the air filter box with it's small pipe inlet tube is for a reason I think so I was never sure about twin open filters right at the back of the engine bay

I don't know if Peter has any experience or views on which might be better, twin open at rear or regular change of internal paper in standard tube box
Nigel Atkins

I have only worked on conversions to twin cone onto the common box at rear of bay with v8 Bs, SD1 type carbs and we have mainly setup cone filters. They seem to work well and add around 10-12 at the wheels over a restrictive standard setup.

Peter
Peter Burgess Tuning

sounds promising then
Nigel Atkins

Interesting, I have two cone filters on my HIF4's that look like they could use a cleaning.
I bought the K&N kit that includes cleaner and oil so now I just need to get it done.
That's after the ice melts and things get back to normal here...

Rick Bastedo

Oh - and that was the day BEFORE our ice storm.
I should have taken another picture, if it isn't all melted today when I get home I will.
Rick Bastedo

Now you KNOW, why they are called Frogeyes. Not for nowt.
Lawrence Slater

ooOOoo cheers for the V8 info :)

what useful people we have here

K&N is on the throttle body now with the drain pipe cleaned out and acting as a cold air feed. Will see how it goes.

thanks for all your help, and that's literally a cool frogeye picture :)
Rob Armstrong

Rick,

check out the photos on the link as your filters might not need (rather than want) cleaning

they used to say cleaning could be left up to 100,000 miles, now they say 50,000 miles (that's inflation for ya!)

of course if you might want to clean it to get back to new(ish) condition or like the color red or just want to use the cleaner and recharger you've paid for

if you can't get it at least as clean as Rob's throw it away :)

link with photos - http://www.knfilters.com/cleaning-pics.htm

ETA: Rob, that sounds a better arrangement
Nigel Atkins

Those photos were actually very helpful.
If mine can wait then I'll hold off and clean them later when they really need it.
We drove through a lot of differing conditions on our 4,600 mile trip across the US and back this past summer so I was thinking a cleaning was probably due.
I'll examine closely, no need to waste a cleaning kit.
Rick Bastedo

obviously for dusty or dirty conditions the milage will be a lot less than 50,000 miles

I always remember that they used to say a dirty was fine but now I have the photos
Nigel Atkins

This thread was discussed between 19/01/2012 and 20/01/2012

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