For What Its Worth

Air Cleaner Deflector

With open air filter elements you can get too much air running through your air cleaner. When driving on the high way or with higher RPMs, air is blowing over you engine. This means it is blowing through your air filter also. This can drop the pressure of air going into the carb. Various things can be done to overcome this. Stock style air clearner casing, functioning cowl induction box, diverter plates around the base of the carb etc.

At first I had a plastic sheet covering 1/2 the air filter, but it limited the function of the air filter.  It did seem to work and give a little better response on the high way. I know, hard to tell and something like this is hard to Dyno.

K&N for dirt track racing makes a "Flow Control Diverter". A plastic shield is part of the system that you can buy seperately.  You attach the shield to the air cleaner base. Primarily to keep mud out, but also stops the blowing of air through the air cleaner. It is rounded to let air flow into the front of the air cleaner also. It comes with six aluminum 1/8", 3.1mm pop rivets, to attach the diverter to the base. My notes on doing this.

  1. Test fit and center the diverter. Take your time. There is a mark that is the "center" on the diverter. Use it to get it aligned with center of carb.   Make sure you have clearances figured out.
  2. Center the rivets so the heads are in the middle of the air filter track. Most air filters have a hump in the middle of the sealing ring, so the rivet heads won't interfer.
  3. Mark and drill the air cleaner base first.
  4. One at a time, working from the middle out, drill the matching hole in the diverter and attach with pop rivets. They provide a washer to help hold on the plastic side.  Don't drop them, they are hard to find. I had to drill out a small nut when I lost one. Aluminum pop rivets may be fine, but I used some stainless ones I had, a little more durable.

Some pictures of the result. This is the 14" version for a 14" air filter.

Since I have to clear an AC compressor also, I cut a notch out to clear the AC compressor.    I left it open for now.  I think the overall effect is minimal with the AC compressor blocking the hole.   This is thermoplastic, so if you find the right material you could plastic-weld a patch.   Foam rubber material or similar could also work to help plug the open area. 

The 1/2" -12mm re-inforcing lip on the bottom can be cut down if needed after the rivets are installed.   It is thin and soft plastic.

Sitting on the carb. 

From the top.  Sorry a little twist in the camera, it looks a lot straighter in real life.

Final result, is it seems to work well.  I have put a few hours of driving on it.  Hasn't changed shape in the heat.  Best advantage is it fits in the cramped engine bay of the Chevy II.    It is not a tight fit to the Air Cleaner on the top, but good enough to perform its function. 

Happy Motoring, VHubbard. Apr 2014

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