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MG MGA - Air Filter Depth

I am going to convert to K&N air filters in my MGA (with standard H4 carbs). I am considering two K&N options: first, a 1.75 inch deep filter, which will fit the standard Volkes cannisters; and second, a 2.5 inch deep filter for which I could use the K&N cannisters. Has anyone tried fitting 2.5 inch deep filters to H4 carbs in an MGA? It's only an additional .75 inch, but I wonder if there is enough clearance to install/remove a filter that deep. Also, am I correct in assuming that a slightly larger filter would improve air flow?

Regards,
M.D.
'57 Coupe
M. D.

You will need the outer meshes to be 2.5 inches deep also, otherwise you will not bee able to tighten the bolts. By the way, I made these into "wing nuts" by welding flat pcs to them - makes it so much easier to do up and undo!(and you cannot see them)
The original airfilters are pretty much wide open - stopping only road kill from being ingested, so K & N of either width will not be much better for air flow, I expect. What they will do is filter better, and apparently they only need reoiling every 100,000 miles (unles you're desert racing!), so pretty much 10 years or more for most people, so that is added convenience.
If you are ordering the 1.813 inch K & N's (direct replacement), E-3212, they are about 8-10 weeks delivery. (I ordered 2 pairs last month).

Peter.
P. Tilbury

Peter:

The 2.5 inch (if they fit in the engine bay) would be installed using the K&N chrome housing, so the MGA mesh would not be used. Also, these K&N's would replace the felt elements that many of the suppliers are selling, not the original-MGA "wire mesh" filters. Would the K&Ns improve air flow over felt elements, and would 2.5 inch (if they fit in the engine bay) have better flow than 1.813 inch?

Regards,
M.D.
'57 Coupe
M. D.

Obviously 2.5" wide would allow more air to flow than 1.75", but would the result in engine performance be significant - I doubt it. Would 2.5" fit under the bonnet - probably, but you could check clearance by fitting some cardboard cut to size to allow you to make measurements. Remember the engine will rock when running, so you need to have additional clearence for this.
I have not tried 2.5" filters, obviously.
P. Tilbury

Peter, who did you order your E-3212s from and at what cost?

Derek Nicholson

Peter:

Thanks. I did check with a peice of cardboard yesterday evening, and there seems to be barely adequate space for the 2.5", but I had the same concern about the engine rocking and don't think it's worth the risk. While 2.5" would clearly filter more air, I imagine that what really matters, for engines as small as ours, is good flow closer to the carb intake. So, I'll probably buy the shorter K&N's.

Regards,
M.D.
'57 Coupe
M. D.

Derek, I got a pair of E-3212s through PartSource last winter. They were special order items and took about 8 weeks to arrive, but eventually got here. Don't remember the exact price, but it was comparable to mail ordering from the US and paying shipping, currency conversion, etc.
Andy Bounsall

I ordered the K&N E-3212 through a local parts store - they all have to go back to the same distributor in Canada as K&N control the sales, and do not sell directly to the public, as far as I can tell. The cost is Cdn$30 (about US$27, or Pounds 15) each (plus 13% taxes here in BC).
None of the "stockists" of K&N on the net stock this model.
Probably better to carefully grind the inlet manifold and head to get better mixture flow to give improved performance, rather than bigger K&N's.
Peter, '56 Roadster and '58 Coupe (latter "under reconstruction").
P. Tilbury

This thread was discussed between 21/08/2006 and 25/08/2006

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