K&N Airfilter for Van's Carb air boxes..
 

Anyone have a fix or resolution of a way to eliminate having to cut a notch out of the K&N air filter where it fits over the accelerator pump of a vertical carburetor Van's airbox setup ???

We've recently purchased an RV-4 with an O-320 in it that's carburetor equipped, and discovered this when we removed the filter to clean and re-oil it.

Just wondering if there's a better way to do this then having to cut a notch in a perfectly good air filter.

At least on my O-360 and carb:

If you are careful when you align the airbox and install the filter 'keepers' on the top plate you don't need the notch. It took a bit of sliding to find where to put the airbox so the notch wasn't needed and the airbox was still clear of the cowl/gear.

Of course this only works when you are initially building (or rebuilding) the airbox.