SonexBuilders.net

I was planning to use the larger air filter on the left, but when I try to put on the lower cowl it is WAY too tall and the cowl hits the filter before it ever comes close to closing up.

http://www.mykitlog.com/users/display_l ... 3043&row=2

I either have to build a blister in the cowl to fit around the filter, or I have to use the shorter filter. I am afraid the shorter filter will not provide enough air flow to the carb. At least that is what I seem to remember in discussions over the years.

Does anyone have any input or thoughts? I don't mind building the blister if I have to, but maybe the shorter filter is OK?

Mike Smith

I used that short filter for a while and had no issues with it. After a while, I switched to a K&N of the exact same size. I can't remember the size, but a search on the yahoo forums will bring up the correct number. I seem to recall it's an E-3120 but I'm not positive. Either way they work fine. like you said, any larger of a filter and you'll have to modify the cowling, which I had no interest in doing.

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So for Mike and Dale, you thought the smaller (shorter) filter was adequate and did not choke off air volume?

Mike Smith

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While tuning my Aerovee engine I found the stock paper filter and the K&N filter E-3120 restricted air flow. Like several other builders with Aerovee engines I installed a K&N RC-1980. To prove this out run your engine with your current filter then without,see how much your max takeoff RPM increases. I believe you will see the need to increase fuel flow (adjust needle) during max RPM requirements such as takeoff. I'm currently running a #3 needle with excellent idle. It only took me about 60 hours of flying the Aerovee to fiqure this out. I have a like new E-3120 and Aerovee filter assembly if some one needs I will make them a deal.
Brent
Onex #77

Hi Brent,

How did you fit that filter under your cowling? I know I barely have enough room with the stock setup. Does the bigger filter rub the cowling at all?

Thanks everyone. I'm going to try the K&N E-3120 since that seems to be working for most everyone. It was only $27 on Amazon with free shipping.

Mike Smith

Same thickness as E-3120 filter,oval shape, twice the surface area so less air restriction. This only matters on takeoff, full power. I just clamp my RC-1980 filter to Aeroinjector inlet.

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