Lotus Elan and Lotus Elan Plus 2 Forums

I'm coverting my Sprint back to the original the air intake system and would be very grateful for some advice/diagramme/photo of where/how the original airbox filter was located and fixed to the body?
Many thanks

The air filter is mounted on it's side behind the grille via two brackets as shown in the attached diagram from the parts list.......

Photos of my S4.....


Hope this helps.

Thanks Roger, that's brilliant
John

Hi John,
Something else I've just remembered....
When you come to fit the air cleaner element you may find that items currently available are too deep to fit in the canister and the cover cannot be fully closed. Functionally it does not matter as it's the "dirty" side which is exposed but it doesn't look right and it can be easily overcome by removing the rubber seals from the cleaner body and trimming down the element.

I'd been hunting for a correct air filter having found the Fram one I'd bought was too deep. Then I saw your post.

Thank you Roger.

The paper filters that are the nearest fit are for the Mk 1 Ford Fiesta .9 or 1.1 litre I believe, Wix WA6401 is one I used to use. However, I have now fitted a foam filter by Pipercross, again intended for the Fiesta - ref no PX03. It has the same fit problems as the others, but I managed to get the lid pretty much closed using it. The foam filter breaths more freely than the paper ones at the cost of slightly increased intake noise. It is more expensive, but can be cleaned, re-oiled and reused unlike the paper ones.

Vernon

I use the WA6401 and squeeze it down in thickness in a large woodworking vice, rotating and squeezing so it all gets done. The paper buckles but doesn't tear.

As the recommended replacement period is 12,000 miles (20,000 km) it's only an occasional job for most people..

You can get a K&N Filter that fits nicely into the original cannister with no fettling. Be careful there are a few that look the same but are too thick.
I can probably find the part number if interested.
Clive

cliveyboy wrote:You can get a K&N Filter that fits nicely into the original cannister with no fettling. Be careful there are a few that look the same but are too thick.
I can probably find the part number if interested.
Clive

I bought one from you a few years ago. I tried to find some more for my other cars, but it seems that part has been discontinued.

I did not realise they have since been discontinued.
I still have a few left if your interested.
Clive

cliveyboy wrote:I did not realise they have since been discontinued.
I still have a few left if your interested.
Clive

I am! Two please

I read a test maybe 10-15 years ago that compared oiled-gauze (e.g. K&N) filters to the paper type. The upshot was that while a freshly cleaned and oiled gauze filter passed more air, 1) passing more air means also passing more finer contaminants (not necessarily a problem for older engines with larger tolerances), and 2) the perfosnve of the gauze filter varied more widely over the maintenance-cycle than did the performance of a paper filter.

But most of us probably won't notice any difference so feel free to ignore this.

Veg
There is the logic that a mesh of a certain grade will only stop particles bigger than the mesh. That is perfectly true if you just have one mesh at 90 degrees to flow. However it is possible to design filters to stop smaller particles with the same mesh with multiple layers and the angle etc at which the air hits that mesh.
The clever bit is getting high air flow with high filtration where the two are usually complete opposites.
Modern filter technology has vastly improved over the years and there are certainly occasions where a performance filter has little advantage over the original manufacturers one. A lot of modern cars run the same filter through out the range so if you have a 200hp car and the air filter is used on the 500bhp model not much logic in going performance after market.
I would certainly choose a new manufacturers filter over a cheap unknown quality performance one.
Clive

Hmmm an interesting thread (the last few posts about the K&N type filter element),
I too bought one of these elements off Clive a number (?) of years ago and fitted it and forgot about it. It was a great replacement at the time - thanks Clive. But now reading this I realise that maybe I should take it out and clean it once in a while, although the car, like many I guess, doesn't exactly do many miles each year.
What is the procedure for this does any one know. If it was oiled (not sure mine was), I guess you cant just blow it out it must have to be cleaned in some sort of solvent. What is it then re- oiled with? Something special I would have thought not just engine oil?
Any ideas?

I was a big fan of David Vizard when I was young. I still have a very dog eared copy of 'How to modify your mini' and a number of minis in my ownership were hacked about following David's advice.

He was a big fan of K&N filtration, and I came across a talk he gave about minis which included a section on K&N. Its all a bit dated now, and I am not sure his explanation of how they work holds much water, but it is interesting none the less.

Section on filtration starts at 4:27

https://www.youtube.com/watch?v=ow5cGV7bXCw&t=188s