K&N Air Filters for Webers - What do I have?

[patssle]

Originally Posted by 911pcars

Not the filter (read post again). Measure the base plate surface, the lip that contacts the outer surface of the filter.

BTW, what's the OD of the filters you have? Form into a circle, then measure.

Sherwood

Using string, the OD/perimeter of the filters is 30.5". The OD/perimeter of the A-style plates is 30.5". The OD/perimeter of the C-style plates is 30.25".

So close, but no cigar. (See pic from post 14 of what happens when filter is inserted into plates)

[patssle]

BeeJay on 914world posted a link to the filter specs. Thank you! Couldn't find them on K&N's site despite searching dimensions or by car.

http://www.knfilters.com/search/product.aspx?Prod=E-3671

Will measure length and width first thing tomorrow morning.

[patssle]

Ok, one last question. On complete K&N kits, do the plates just slide right on the filter very easily, or do you have to bend the filter?

I've done the measurements and it looks like the new filters (linked in last post) will fit my plates. I'm just perplexed that K&N would make filters of the same type but just a millimeter bigger - am I doing something wrong? As this is what happens when I put them together:

[enzo777]

Hi, i want buy, your metal base stock air filter housing, you put "B" in them
if taht possible
regards
Enzo

[patssle]

They are for sale, sending you a PM.

And I still need a cast aluminum base plate (A in my photo) if anybody has one. Would be willing to trade C and/or filters for it. Or money.

[911pcars]

Just a FWIW. K&N isn't the only manufacturer of pleated gauze filter elements. I'm fairly certain other competing filter companies have a similar range of filter sizes for cars, trucks and other vehicles. Are you sure those are K&N branded filters for the K&N housing?

After many years of looking, I've concluded that K&N designed and manufactured a uniquely sized gauze filter for their individual Weber carb air filter housings (I recall measuring the OD as 9" once upon a time, but I've lost track - don't quote me). I've found no other filter in paper, foam, etc., no other OEM vehicle or off-the-shelf filter will interchange properly into a Weber/K&N filter housing (too small, too big, too tall, too short, etc.).

Filtron foam filters and filter housings (item C in the first photo) preceded K&N's version. However, the Weber/K&N filter will fit into a Filtron housing. Not sure how universal that fit is. However, they fit in the ones I have.

Sherwood

[unclebilly]

I have 2 brand new k&n filters for the k&n setup. They fit snug in the bases and the tops.

Look sat the picture of the engine in this thread, one of the tops isn't pushed down all the way.

Engine Back in Car

I bought one of these and had to order the other from k&n which took months, I understand these are nla.

On another note, I have been running this setup for a few years and have had no need for rain shields.

[mskala]

This is as good a place as any to report that I found a paper filter for K&N which is the
right dimension except for being 1/4" taller. You can use a spacer for the bolts or go to
springs on the edges as shown here.



This is originally a round filter. To allow it to become oval, I clipped the metal mesh from
the outside only. It may be possible to avoid removing it if instead you put vertical cuts
in several places around.

[911pcars]

Excellent detective work. What vehicles is this designed to fit?

You should get a collective round of applause from all Weber carb owners.

Sherwood

[mskala]

I don't know but I'm sure somebody could find out from the counter
personnel at their FLAPS.

This is what I think the list is for equivalent parts:
Fram CA192
STP SA192
Wix 42088
Purolator A30067

[911pcars]

Originally Posted by mskala

I don't know but I'm sure somebody could find out from the counter
personnel at their FLAPS.

This is what I think the list is for equivalent parts:
Fram CA192
STP SA192
Wix 42088
Purolator A30067

According to another filter website, these filter numbers are also compatible with the Fram CA192 and Purulator A30067:

AC-Delco A178CW
AC-Delco A178CWK
AC-Delco A333C (product photos show some sort of "wrap" over the paper element)
Air Refiner 27576
Amsoil EAA32

Dimensions (not all above are identical, some minor variations):
Height: 3.54"
I.D: 8.20"
O.D: 9.71"

Of the above, which filter is best?

S

[KTL]

Fantabulous!!!

I'd say the Delco or the Wix are a good bet. STP seem kinda cheap and flimsy from the ones i've handled. Fram isn't a whole lot better.

I'll make note of these numbers and do some hands-on comparo work at the local parts stores. I've got a bunch of chains in my area so I should be able to get my hands on most all of these w/out having to buy anything- yet.

Big ATTA BOY goes out to Mark. I knew there had to be a standard type filter out there that would work for our Webers.

[KTL]

The majority of the filters listed are around $5.

AC-Delco A178CW
AC-Delco A178CWK
Fram CA192
STP SA192
Wix 42088
Purolator A30067

Are all around $5 if you shop around online. They're all basically the same filter element- rubber surround, paper element, wire screen

The Delco A333c is some sort of odd polywrapped filter probably intended for off road (extremely dusty) use. When I did a search, it came up as a GM filter for any TBI or carbed vehicle from 1990 back to the 70s. 400+ vehicles were listed for this filter!

The amsoil is a reusable filter for $29.95

Amsoil EA Air Filters EAA32

[KTL]

By the way, the Purolator will increase our cars's acceleration by up to 11%

Purolator A30067 Car Air Filter Replacement Only $3.49

Dang, I know which one I'M buying for my race car!!!

[911pcars]

BTW, notice the two different color filter elements in the above "K&N" filters (the slightly too big blue element). FWIW, K&N filtering elements are typically brownish, not blue. The blue version may indicate a different source/different application.

The alternative paper filters should be good. Paper filters usually provide better filtration, and while they aren't reusable, they're cheap enough to replace as needed.

Sherwood

[911pcars]

I finally got around to update my attempts to adapt pleated paper air filters to replace the standard K&N oiled cotton gauze filters.

I sourced a couple of filters from the FLAPS (AC-Delco A178CW, about $4-5 ea.). As in previous attempts shown, these pleated paper filters are a very tight fit into either housing. However, the K&N al. cast bases/tops are slightly larger by a few mm than the lighter stamped al. housings by Filtron). However, these filters are replaceable and cheap. Many independent tests show pleated paper filters do a better job than the supposedly superior K&N oiled versions.

Comparison
The AC filter is this much taller than the K&N:


Installation
Instead of removing the outside metal grill (see Mark's post, #28), I opted to remove the inner screen to reduce resistance to modify the ID to fit better. Careful. Wire ends are sharp. Use pliers or equivalent.


Pull random wire strands from the rubber surround. This reduces the number of puncture holes in your hand as well as avoiding loose wire ends sucked into the intake.


Per Mark's option B, I removed two sections of outer grill to again reduce any resistance to reshape the filter.


It's still a tight fit in the Filtron housings. There's still a tendency for the sides to bow slightly inward (exaggerated in post #23). I bent some scrap material in a U-shape to keep the inside walls parallel.

Completed install in my 914-6 conversion:


Sherwood

[Vin-barrett]

Search function pays off..Great info here.
Since this 3 year old post has anyone preferred one of these brands over another?

[911pcars]

Not sure the following differences were shared.

The Weber filter housings using springs to clamp the filter were sold by Filtron along with their foam filters (NLA but perhaps sold by others). The housings are stamped aluminum and thus very light.

As shown, the K&N filters for their Watershield housings may not fit those Filtron housings. In addition, the housings are stamped steel and slightly heavier.

Hope this helps,
Sherwood

[Vin-barrett]

I used the Fram. Certainly not a perfect fit but it does work.
Thanks again for this info

[911pcars]

Here's an adv. blurb from a source for ITG air filters. They might have filter material suitable for other formats.

https://www.merlinmotorsport.co.uk/s/itg-air-filters