Upgrading Your Air Cleaner Assembly
A few years ago I purchased a 1986 Camaro that had a carbureted small block chevy swapped into it. When I bought it there was no air cleaner, so naturally I stopped at the closest auto parts store and grabbed the first assembly that I found. This one wasn’t bad by any means; it was shiny, it said ‘Edelbrock’, and most importantly, it filtered quite a bit more than the empty space that was currently there.
Not long after purchasing I parked this car in the garage to do some major work, and as is the usual story, it was sitting for longer than I had originally intended. Earlier this year I got it out on the road again, but after a few drives it was pretty apparent that the engine was not getting the air that it needed - it was sluggish and slow to respond to the throttle. Now the easy solution to this, and definitely the best one if you have an air cleaner assembly that you like, would be to replace the air filter. I used this situation as an opportunity to upgrade it all!
Now air cleaners are essential not only because they filter the air going into the engine, but they also straighten and diffuse the air helping it flow easier and freeing up a little extra horsepower. While I wouldn’t say that upgrading your air cleaner gives you more horsepower, it allows your engine to more easily make the power that it should. Your engine needs to suck in quite a bit of air while running, and the larger area it has to suck it through, the easier it is to do so. Think of it like drinking a soda through a stir stick compared to through a normal sized straw. The air cleaner that I had was about 10” wide and 2” tall. Not terrible by any means, but there was definitely room to go larger.
Before you go about this, you can save yourself quite a bit of trouble by measuring before you order. The main things you need to look out for are clearance from the top of the air cleaner to the bottom of the hood, and clearance from the bottom of the air cleaner to any of your engine components. There’s a little bit of math involved here, but it’s very simple. To start, my air cleaner sat directly on top of the carb and was 2” tall. Easy. I was eyeing the Speedway Motors Air Cleaner/Outerwear Filter Kit, which includes a 14”x4” filter, a super flow filter top, sure seal air cleaner drop base, sure seal o-ring spacer, and an outerwears cover for it all. All of these components have their own measurements, so we need to do some adding, subtracting, and measuring.
The o-ring base included in the kit is 1” tall, the air cleaner drop base drops the air cleaner 1.5”, the filter is 4” tall, and the super flow top is 1.5” tall. This translates as 1” (o-ring base) - 1.5” (drop base) + 4” (filter) + 1.5” (top) = 5” tall. This helps, but it’s not all that we need to figure out. With the 1” space and the 1.5” drop base, the bottom of the air filter is going to sit about ½” below the top of the carburetor - and being a 14” filter it will sit out 7”. This car had a cowl hood when I bought it, so I had gobs of real estate to fit a big filter into. However, with a wider and lower filter, I was going to have a bit of trouble with hitting the distributor.
It was going to be close. I could force it if I wanted to, but in the end, since I wasn’t worried about being an extra inch higher, I chose to get a 2” o-ring base to raise everything up just a bit more and avoid all interference. This measurement you can pretty easily check with a ruler or tape measure. If you’re wondering how to check for cleaner-to-hood clearance, and don’t have the luxury of being able to see in from the driver seat through the cowl, an easy method to use is to make a ball of modeling clay or aluminum foil roughly the additional height of your new filter (e.g. 4” tall ball of clay for me, as my new assembly is 6” tall), set it on top of your existing air cleaner, close the hood, and see if it squishes the ball at all. Test this in multiple places around the circle to be absolutely sure that you won’t run into any clearance issues. Lastly, make sure you have a long enough stud to accommodate your taller cleaner. My current stud was 5.5” tall and stuck 4” out of my carb.
This was most definitely not tall enough to lock down the new filter. Luckily, we offer the Air Cleaner Stud, which is 9” tall, and will stick out of my carburetor 7.5”. With the taller o-ring spacer my entire assembly will be 6” tall, so I don’t need quite that much and that’s right on the limit of my hood clearance, but it’s no problem to cut that down just a little bit to get a perfect fit. With the new stud installed, all that’s left to do is the fun part! Put the o-ring base on first, the drop base on top of that, followed by the air cleaner, and lastly the super flow top.