This is the start of a short series about the right treatment of nitro engines and some of their components. Today we start with one of the most important questions: Should an airfilter element be reused?
Whether you drive on- or off-road cars, buggies, trucks or whatever; as long as your RC-car has a nitro or gas engine, its carburetor is equipped with an airfilter. Well, it SHOULD be equipped with an air filter. NEVER EVER run your nitro car without one as these filters avoid dust, dirt and moisture from getting inside the carburetor and therefore into the engine which is a potential threat! But that's a different story.
Back to the air filter itself. In former days, some 20 or 30 years ago, airfilters actually where modified paper fuelfilters as found in one or the other road car. You had to throw them away after they are done. That was costly and not very environmental-friendly. But development went on and today we use filter with interchangeable foam elements. We divide between one and two stage air filters. Cheaper filters sport a plastic cage with plugged-on foam filter element; the so called one stage filters. Two stage filters feature a second, slightly larger foam above the lower one for added filtering performance. More important (sort of) than the foam itself is the fact that it (the foam) needs to be oiled with special foam airfilter oil. Although some manufactures claim that they have THE ultimate airfilter oil it is more important to actually treat the filter elements as even with the foam attached the small pores let dust particles pass which then can harm the liner and piston of your nitro engine like and abrasive paste.
With so much words spend to make clear that you have to use an airfilter and that it is important to treat it with special oil, a question we often hear is: "Can an airfilter element be cleaned and reused?". The short answer: "No!" We have seen and heard this many times and often discussed it with engines experts most of which warned to re-use airfilter elements.
Some say you can clean the foam with denatured alcohol or dish liquid but this only removed the visible dirt. Dust particles and even larger grain of sand can still be hidden within the pores only coming out when the element is being re-used. Therefore never ever clean and re-use an element even if it looks clean but always use a new piece of foam. They come to cheap as to ruin that expensive engine! And if you say you don't like oiling the foam filter elements (because it can be quite a messy job) you can rely on pre-treated foams (like the ones on the right) from various manufactures. For those who own a RTR car or truck and don't know how to perform the foam element change, see below how to.
Disassemble the filter. You can clearly see this Xray airfilter is of a two stage design with inner (thicker) and outer (thinner) foam.
Clean the inner and outer parts of the plastic cage with motor or brake cleaner.
Oil the new Elements with your choice of airfilter oil.
Attach the inner foam by slipping it over the cage and reatach the outer plate.
Attach the outer foam. Et voilà!
