SU filters

[Michael Oritt]

I installed a pair of SU filters (BCF advertiser I believe) on my wife's 3000 MK I. See attached photo. The installation was pretty straightforward and involved first fixing the inner plates to the carbs, then mounting the filter elements and finally the outer plates using lock nuts over the outboard ends of the studs. Accessing the forward nut on the front carb is a bit difficult but it will probably be a bit easier to pull the plates to clean and reoil the foam elements than with the original metal filters. You'll see I had to reroute the hose to the rear filter under the fuel pipe because the nipple does not angle up as on the stock element.

The filters look nice and the red matches nicely the color of the Mallory componenents. BTW the Austin-Healey logo is barely visible if one is standing by the left fender.

 

[Michael Oritt]

Re: SU fliters

Here's the installation viewed from another angle.

 

[gonzo]

Re: SU fliters

MO - This resolved a concern I had about the breather hose location. Thanks for sharing the pics. The air filters coordinate well with your other engine components. A similar upgrade on my car would probably complement the yellow/black Bumblebee copper wire ignition set I just installed. Perhaps I’ll give this further consideration, but first need to trace oil accumulation in the rear carb from the breather hose. What are your thoughts on improved air flow of the new filters? On Oil-mesh vs. Foam Filtration Elements? Thanks again, GONZO

 

[Michael Oritt]

Re: SU fliters

[ QUOTE ]
need to trace oil accumulation in the rear carb from the breather hose. What are your thoughts on improved air flow of the new filters? On Oil-mesh vs. Foam Filtration Elements? Thanks again, GONZO

[/ QUOTE ]

Is oil spurting out of the holes in the rockers--if so you'll need to have that addressed.

Dunno whether there is more or less air flow though I have never been impressed with the ability of metal gauze units to catch abrasive dust, etc. But truth be told, I bought the filters because I like their looks.

 

[gonzo]

Re: SU fliters

Hi MO – Thanks for the tip on the rockers. On my BJ-7 the oil level is running MAX on dipstick which may account for the oil residue in the breather tube. As a rule the crankcase is filled between MAX and MIN marks, but I was distracted while doing the last oil change. The rockers, though rebuilt by a reputable source, will be checked again to make sure they’re not spraying excessively, but if it needs repair, then there's goes my budget for the SU Carb Filters! I also like the look and wanted them ever since they were advertised. I’ll do a search on rocker arm specialist. I think there's a reputable one in Anderson, California. GONZO

 

[davelgee]

Re: SU fliters

"What are your thoughts on improved air flow of the new filters? On Oil-mesh vs. Foam Filtration Elements? Thanks again, GONZO".

Let me quickly address this question, since I have already worked it out. The stock coopers air filters have about 40sq." of open surface area , the su filters that Michael is using are about the same in exposed surface area. UNI tells me that their elements will flow 6-CFM per surface sq" @ .125" Hg pressure drop. This works out to 240cfm.
This is slightly below the 270cfm that the MKI Healey requires at peak HP (180cid X 5200rpm / 20840 = 44.91 X 6 = 269.5-CFM) so it is pretty much a wash as far as air flow goes, that is, except for the "Brillo pad" and extra screen on the carb side of the coopers ;-).

"I have never been impressed with the ability of metal gauze units to catch abrasive dust, etc. But truth be told, I bought the filters because I like their looks."

Thank you Michael, In future I will raise the AH logo engraving as high on the filter as possible.
I think an air filter is first and foremost a filter, and should be chosen for it's filtration ability, in this case, not a close call. On the big Healeys, especially the twin carb models, there is only one way I can see to have your cake and eat it too, and that is a filtered cold air box.
The Tri-carb MkII with 360cfm potential can run the standard su-filters.

Cheers!
Dave G.