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A Breath of Fresh Air

By Ryan Ballou

I would have to say that one of the most frequent complaints I hear from people running dual carbs is that of clogged jets. The causes are fuel contamination and/or dirt getting past your air cleaners. Dirty fuel is easy to deal with, run a fuel filter, check and service it regularly. Cheap stamped steel air cleaner assemblies however can be a little trickier to deal with. Lucky for us dual carb enthusiasts Mid America Motorworks has a solution, billet aluminum air cleaner assemblies.

Now as any of you know, most of the dual carburetor kits currently available come with a stamped steel air cleaner housing. I've lost count of how many of these I've either broken or warped over the years. The result is a loose, poorly fitting air cleaner base that does nothing to seal the assembly to the carburetor. When you take into consideration that the idle air bushes are open on the top of the carb you can see how any debris getting past the air cleaners can easily find it's way into your idle jets. The problems only get worse when the spot-welds on the tabs that hold the securing studs in place break preventing you from securing the air cleaner tops.

The solution is found in the rigid design of the billet assemblies made by EMPI and marketed by Mid America Motorworks. Now I have to come right out and say this, don't let the name EMPI deter you. These are quality pieces of work. When I removed these from the packing material they were shipped in, the first words out of my mouth were "WOW, these things are heavy". Heavy isn't always a good thing in the world of performance, but in this case I'd prefer heavy over cheap.

First the terminology; the word billet as it applies to metals means a solid bar metal that was either rolled or forged from an ingot. It is then from this 'chunk' of metal that a part is machined. This process yields a very strong part with a fit and finish limited only by the quality of the machining process. In this case we get a pair of air cleaner bases and tops that fit and work exactly as they should.

The bases are machined perfectly flat for a solid seal against the tops of the carburetors more than can be said for the flimsy steel of the originals. The inside of both the top and base have channels machined into them to secure the air cleaner elements in place. The bases are countersunk on the bottom to allow bolts to pass through to risers that in turn are studded for nyloc nuts that secure the top halves. Finally, all the visible surfaces are polished giving a very clean look.

Installation of these is very straightforward. The only tips I can offer to smooth the process are these. Make sure the bolts and studs are secure in the risers. If not then you should disassemble and clean them then reinstall with some thread-retaining compound. Make sure to mind the height of the top studs so that they all protrude equally through the air cleaner tops and enough threads are exposed to fully engage the nuts.
You will have to back out the mounting studs install in the tops of your carburetors so they reach high enough to compensate for the thicker bases. If you're running the original Weber velocity stacks the stock studs should be long enough. If you're running aftermarket stacks then you may need to purchase and install longer studs. You will also want to smear a layer of grease to on the supplied gaskets to ensure a good seal. The included air cleaner elements are the serviceable gauze type, meaning you will need to purchase a bottle of air cleaner element oil and coat them prior to use.


These are easily the nicest set of air cleaner assemblies I have yet to see from ANY vendor that are not full on custom units. The quality and finish is well worth the slightly higher price tag as these will outlast and out perform the originals and look great doing it. My thanks go out again to Mid America Motorworks for supplying the VW community quality products such as these.

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1-The stock air cleaner assembly as was provided isn't much to look at.
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2-Assembled, you can see a hint of the differences setting these apart. They just plain look sturdy.
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3-Inside the differences become apparent. Notice how the mounting tab has broken at the spot weld. This is probably the most common failure point for these.
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4-Take note how the bases for the rises form channels to secure the lips of the elements in place. You can also see here how thick the bases are, no risk of warping these.
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5-The tops of the original set are identical to the bottoms. Just a piece of steel with a stamped lip.
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6-Having been machined from a billet allows for the addition of the channel to be added to retain the elements.
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7-Nothing too special about this, it looks just like any other engine bay out there.
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8-The new billet assemblies seem to be the first thing anyone notices now when they see my engine. There's something to be said for a part that not only works good, but looks good too.
 

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