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Need Tip for Replacing 0-320 Air Filter with Accelarator Pump Cut Out

alpinelakespilot2000

Well Known Member
Need some suggestions...

I'm at that point where, after 8 years of flying, I should probably replace my K&N air filter for my vertical draft carb0-320 given that it has fallen prey to the incredible shrinking filter syndrome. Although it still smashes up nicely between the FAB plate and the FAB floor, it has definitely lost some circumference.

The challenge for the 0-320 carbed version is that you have to cut out part of the filter to clear the carb accelerator pump then proseal around it to get a good air seal. While building this was easy. I had the carb off the engine, just turned it upside down on the table, waxed around the accelrator pump, placed the filter on the carb, then shoved proseal into the cutout I made. However, I'm kind of reluctant to pull the carb off the plane to do it again though, that's my default absent better ideas.

Anyone have any tricks or tips to alter a new filter as necessary without having to take the carb off the engine?

Thanks for any thoughts.
 
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I've done this a couple of times. Just pull the old filter, cut the new one about like the cut in the old one, slather the cut-out in proseal, put tape or wax over the accelerator pump protrusion, and re-attach the filter. You may need to add more proseal at this point.

Let it cure for a day or two, remove the filter, remove the tape, and reinstall the filter.
 
I've done this a couple of times. Just pull the old filter, cut the new one about like the cut in the old one, slather the cut-out in proseal, put tape or wax over the accelerator pump protrusion, and re-attach the filter. You may need to add more proseal at this point.

Let it cure for a day or two, remove the filter, remove the tape, and reinstall the filter.

Thanks Kyle. Sounds like I might have been overthinking it. Do you just use the FAB itself to hold the filter up in place tight against the carb while the initial application of proseal cures?
 
I switched to KN E-3322...slightly larger ID...it generally doesn't require modification around the accelerator pump
 
Thanks for the suggestions, both to Kyle for the technique and to the others for suggesting I might be able to get away with a larger filter. Anyone know off the top of their head what the original filter model number was? (I'm curious about how different the size is and I'm not close to my plans.)--Edit: Just found it on Van's website--it appears O-320 vertical draft uses E3260.
 
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--Edit: Just found it on Van's website--it appears O-320 vertical draft uses E3260.

Thats it...take a look at the spec on K&N...If I remember the ID was larger but the OD was similar, and the CFM rating was close.

I do oil analysis and my silicon levels are about the same, or even went down slightly with this filter. Actually, Blackstone offered the unsolicited opinion that the air filtration was good.
 
If you are using the original filter size, trim the filter to fit then use Saran Wrap over the pro seal then after the pro seal sets up, peal off the Saran Wrap. Worked for me...
 
Suggestion

I just completed this very task. Food for thought :

Use a dremel composite cutting disc to creat the depression. Cuts nicely in the metal mesh.

Think about Ultrablack silicone as the “potting filler”. Comes in a tube, no mixing, fuel proof and cures quickly.
 
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