Pancake Filters

Date: Thu, 8 Oct 1998 18:03:56 EDT
Subject: [imps] Pancake Filters

> Just fitted chrome pancake filters - they allow so much more air through
> that the fuel mixture has been made leaner - I know this shouldn't
> happen with CD carbs. I recommend everyone to buy these air filters
> which only cost 8 pounds each because they do away with the need for
> that stupid (and heavy) intake box on the sport. If you are feeling even
> more adventurous at a later date, you can replace the actual elements
> with genuine K&Ns!

What filters the Air??

If it's wire mesh then throw them out as soon as possible , your lovely new engine Pistons and bores will be destroyed in no time as it ingests dust ! Much better are the Foam 'socks' which are available now , and they do actually keep out most of the particles which are in abundance around the rear of the car ..

Nick ...

Date: Fri, 9 Oct 1998 00:53:24 +0100 (WET DST)
From: Ewins, Paul
Subject: RE: [imps] Pancake Filters

I've got the foam socks on my Webers, but only becasue nothing else will fit. Their filtration effect seems based on the idea of not letting anything through, including air. I actually have a couple of nice big K&N filters sitting on a shelf in the garage, but the chassis bars are too close to the carbs to be able to fit them on. Such are the joys of kit cars.


From: Dave Edge
Date: Fri, 09 Oct 1998 01:10:20 PDT
Subject: [imps] Re: Pancake Filters

Hi Nick,

These filters are both aluminium mesh and foam. The mesh sits either side of a foam block to provide structure. They should filter more air than the socks because of the surface area advantage - they are around 6 inches in diameter. I think the major performance gain comes from the fact that they are bolted straight onto the carburettor without those 'U' bends so that the only limiting factor is the diameter of the carburettor (i.e. 1.5 inches). I think the reason for the change in the fuel mixture is that the airflow is now at maximum speed in the centre of the carb aperture rather than at the bottom with the 'U' bends (This is assuming that air flow is fastest on the outside of a bend).


From: Gary and Carol Henderson
Date: Fri, 9 Oct 1998 22:29:11 +-1300
Subject: [imps] Re: Pancake Filters

Hi Dave

Do your filters incorporate an intake-trumpet at the mating to the carburettor? A Stromberg is likely to work 'differently' if this part is absent.



Date: Fri, 09 Oct 1998 11:37:23 +0200
From: Bert Clewits
Subject: [imps] Re: Pancake Filters

Hi Dave, Nick,

Those filters sound good enough to me, where can I get them ? (the chrome ones) and how much are the filter socks and where can I get those.
I've got the std 1.25 strombergs with elbows on my Stiletto.

What about filters which are cleanable are they any good ?


Date: Fri, 9 Oct 1998 11:02:14 +0100 (BST)
From: Paul Waites
Subject: [imps] Re: Pancake Filters

Hi All,

I have been using K&N cleanable filters for a few years now, they are a bit messy to clean and re-coat with oil, but they seem to be doing the job. They are probably a bit of an expensive outlay initially, but I do believe that they allow the engine to breathe more easily. (I'm using a webber 28/36 by the way, but I have seen them on Stombs).


From: Dave Edge
Date: Fri, 09 Oct 1998 03:42:41 PDT
Subject: [imps] Re: Pancake Filters

Hi Bert, Gary

Speedy Spares sell them for 8 pounds each, filter socks are available from Pipercross and Ripspeed sell them for 16 to 20 pounds for a pair.

The price difference is negligible, I decided that the Chrome pancakes looked just that little bit better. The pancakes bolt straight onto the carburettor body whereas the socks fit over the elbows.

In the end it comes down to whether it is better to have lamina or turbulent air into the carburettor on entry. I believe it is better to have lamina at this point so that the fuel metering is more predictable. If this is the case then the rough elbows are better removed. As I understand it, the less joints in a pipe the smoother flow. On the other hand the elbows may be doing a good job by funneling the air into the right shape to hit the carburettor body.

There is no simple answer to any question is there!