English French German Italian Spanish

Atlas air filter

Submitted by michael_coare on Wed, 16/03/2022
Forums
Heavy Twins

Whilst most pictures of an Atlas show them with "naked" carbs ie short or even no bellmouth intakes. I've seen a few pics showing them with a wedge-sectioned arrangement squeezed inbetween the 2 carbs and the oil tank/battery box.See pic.

I'd love to see some more info and detailed pics of this type of airbox if anyone has one. Could be interested in one at a reasonable price, as I've been unable to find one so far.

TIA

PS note the club shop has a D shaped air filter for a single carb setup, which looks to be sandwiched between the oil tank and battery box, its listed as being fitted 1953-1960. Any idea why it was dropped, as it seems like a good idea. Cost maybe?

Attachments
66Norton-Atlas-silver-engine-R.jpg

Submitted by david_comeau on Thu, 17/03/2022

Permalink

There are 3 types of slimline filter AFAIK

chopped monobloc, 389/689 for 66, and concentric 67partial and 68.

Following is 2 of the 3 filter bodies. I own a 63, 66, and 68 atlas and will one day find the 3rd filter without "dimples" that accommodate my 68 concentric carbs.

You might note the double dimple filter body type , the rarest, could be the universal type to use on any two carb type slimline.

 

slimline filter body

Submitted by michael_coare on Thu, 17/03/2022

Permalink

David, that picture is great, thanks! If you have the time to spare, any further photos would be very much appreciated.

Is there a "proper" element, or does it simply work by the gauze slowing down the air intake?

Also, there are clearly 2 bosses for mounting studs- where do their other ends fit, I guess there's a matching plate of some sort on the manifold?

Submitted by david_comeau on Thu, 17/03/2022

Permalink

Agree the original gauze  filter material could be improved, but still better than nothing!!! The attachment flat plate is retained on the mouth of the carbs with the screw on rings like the commando type. There are fat grommets set into the openings to seal against the carb adaptors/ retaining rings. Sorry no current pix in hard drive..

I might speculate the carb mount plates are matched to the carb adaptor rings diameter as monobloc and concentric differ slightly,  yet center to center dimension will not!

After market are not like my original style.

The mount plates have 2 holes for bolts, probably 5/16 CEI and 2 bored openings to slide on the mouth of the carbs.

 

Submitted by robert_tuck on Fri, 18/03/2022

Permalink

I am informed by a fellow  Club  member  that there are   4 types of  the wedge filter boxes  that were made for the big twin ,this  likely  includes the  Off road  bikes,  but also makes it harder to ID   the bits you  need.

Submitted by michael_coare on Fri, 18/03/2022

Permalink

Thanks all. I have since found an earlier thread on the topic

"Air cleaner 63 Atlas, Submitted by Ernie Olivo on Sun, 01/04/2018".

This has 2 attachments, however I can only open the first, the second file doesn't appear to be in a picture file format.

I also came across a (closed) auction item on't interweb which showed the filter dismantled- very helpful. See attached.

Attachments
dismantled air filter.png

Submitted by robert_tuck on Fri, 18/03/2022

Permalink

With the current  scarecity of  afordable  quality replacements  it  makes  complete sense to protect your  motor with an air filter  and an oil filter.  I have had an oil  filter kit  on the shelf for  many years,  If it had been supplied with  correct fittings (!)   it would be in place  , With the detergent oils that are  now  prevalent  circulating  the  detritus I  need to get this done. A modified Austin Mini air  filter element  is keeping my rings and bore  perfect after  25 years of classic riding  use.

Submitted by paul_nicholls on Wed, 23/03/2022

Permalink

I believe Norvil has these air filters with the differing types for monoblocks and concentrics.

Submitted by michael_coare on Fri, 25/03/2022

Permalink

Norvil are indeed showing several options for these (search filter-air-Atlas), thanks for the suggestion Paul.

The prices look a bit rich for my palette (and pocket!), but I suppose they simply reflect the reality these days of small-scale manufacture. No such thing as a ten quid bike any more....

The mounting plate onto the carb mouths looks suspisciusly like a plate I have in a box of assorted carb bits tucked away somewhere in the lockup, and not readily accessible. So just need the filter to fit it to!

Oh well, the autojumbles are opening up again, so maybe I'll get lucky some time soon. Still at the "parts gathering stage" of this project, it's not a priority.

Again, thanks all for comments and infos- at least I know what I'm looking for now.

 


Norton Owners Club Website by 2Toucans