RV-10 Air filter box problem

mikelupo · #1 04-10-2023, 05:31 AM

Sorry. I have no photos to support this post.

This is a flying RV-10 (1100 hours) that uses the Van's provided filter airbox for the K/N-E3450 air filter.

I noticed during condition inspection that the filter does not fit snug at the top of the airbox anymore. I can see about a 1/4" gap. Thinking the air filter shrunk from washing/drying and re-oiling, I purchased a brand new one. Same outcome. My only conclusion here is that the airbox itself is the issue.

I think the problem is that the lower part of the air filter box has lost its "stiffness" or shape and no longer provides enough support to keep the air filter snug at the top.

Aside from ordering a new airbox kit (which are back-ordered), I'm curious what other owners have done to address this. Surely I can't be the first.

Thanks,
Mike

Tooch · #2 04-10-2023, 05:41 AM

Epoxy a sheet of aluminum on the bottom of the airbox. It will also keep the filter from rubbing through the fiberglass.

lr172 · #3 04-10-2023, 06:14 AM

Quote:

Originally Posted by Tooch

Epoxy a sheet of aluminum on the bottom of the airbox. It will also keep the filter from rubbing through the fiberglass.

+1

I add a piece of Alum to the bottom to prevent the F/G from wearing away. In your case, just modify size or qty of Alum sheets to get the height you need. However, be sure to match drill the drain holes.

larrynew · #4 04-10-2023, 06:18 AM

Quote:

Originally Posted by Tooch

Epoxy a sheet of aluminum on the bottom of the airbox. It will also keep the filter from rubbing through the fiberglass.

+2

500 hours and filter still fits perfectly.

rvanstory · #5 04-10-2023, 07:31 AM

Quote:

Originally Posted by larrynew

+2

500 hours and filter still fits perfectly.

+3 Same with my RV-10 after 420 hours.

dhmoose · #6 05-05-2023, 09:25 PM

For what it is worth, I have seen the filters dimensionally change after a year of use. They typically shrink circumferentially and it is noticed by finding the old filter having space between it and the small tabs that keep it in place. I vaguely recall Vans speaking to this issue years ago but it seems like the only remedy was to replace the filters annually as opposed to cleaning/oiling the lifetime filters when needed. During my inspection today, I removed the air box and saw that the old filter didn’t seem altered. When I went ahead and placed the new one in to compare, the new one was dimensionally smaller in height and didn’t make contact with the top plate allowing air to bypass the filter. When I compared the two filters side-by-side on the bench, there was an an obvious height difference. Strange.

Walt · #7 05-06-2023, 07:14 AM

Do a search on "shrinking air filters".

Kyle Boatright · #8 05-06-2023, 07:37 AM

Quote:

Originally Posted by larrynew

+2

500 hours and filter still fits perfectly.

Interesting. 85 hours on the one in the Rv-10 and the bottom shrank in diameter so much the filter no longer sealed against the air box. I assume the bottom sees more fuel exposure in shutdown than the top and that was the causal factor.

The filter was cone shaped when I removed it.

The ones on the RV-6 have lasted 5 years or so.

ScottSchmidt · #9 05-13-2023, 12:00 AM

Like others have said, it has shrunk and needs to be replaced.
You be surprised how much it has changed shape when you get the new one.
Once you look at it again you will also see how much it has shrunk in diameter. I just replaced mine again this annual.
I think this is the part number for the Tempest brand rather than K&N.

https://www.aircraftspruce.com/catal...s_08-17580.php