Air filter housing for a motorized towing vehicle or snow blower

On many motorized towing vehicles and snow blowers, after a snowfall, the engine starts to run unevenly, arbitrarily decrease and increase its speed (the engine speed becomes noticeably "floating"), loses power, and sometimes even loses the ability to move the equipment. This is especially noticeable if the outside air temperature is not too low.

The reason is that fluffy, unpacked snow easily rises into the air, as they say in the North - "kurzhit", that is, it creates a cloud of snow dust. This dust penetrates through the cracks of the factory air filter. The vacuum in the air filter housing "pulls" hot air from the nearby red-hot muffler housing of the exhaust system. This heating of the air sucked into the air filter housing further increases the moisture content in the sucked air. In the carburetor channel, the air cools due to the vacuum, and the moisture condenses on the walls of the channels in the form of frost, causing the carburetor, jets, and valve to freeze. This freezing over-enriches the mixture and disrupts engine operation.

There are two ways to avoid this phenomenon:

1. take colder air further from the exhaust pipe and cut off the snow dust, preventing it from melting inside the air intake system;

2. take hot air directly from the muffler body, and thus increase the temperature of the sucked air to such an extent that when cooling in the carburetor, the moisture will not freeze on its walls.

The second method can reduce the engine life.

The implemented filter design allows you to implement both options.

A corrugated technical plastic pipe with a diameter of 40 mm is put on the filter housing branch pipe, which is either diverted away from the muffler (for example, higher and further onto the control pipe), or, conversely, pressed against the protective mesh of the muffler housing. Another suitable pipe will do.

In the first case, a fine mesh is put on the far end of the pipe to cut off snow dust (a piece of thick nylon women's tights will do), which is secured with a clamp or tie.

Tested on the Bars Sledopyt motorized towing vehicle with a Honda engine.

Printing on K1, nozzle 0.4, layer 0.2:

1. housing base - PETG, 4 walls (for rigidity), filling 20% gyroid;

2. housing - PETG, 3 walls, filling 15% gyroid, with conventional overhang supports up to 60 degrees, supports only from the table;

3. Gaskets in the air filter housing base hole - TPU, 2 walls, 15% gyroid filling;

4. Gaskets on the upper part of the air filter - TPU, 2 walls, 10% gyroid filling;

5. Insert in the housing base - PETG, 100% filling.

Gaskets on the upper part of the air filter are needed due to the different heights of the supplied air filters. As a result, a fairly large gap is formed between the top of the air filter and the upper part of the filter housing. These gaskets compensate for this gap and allow you to eliminate the second wing nut inside the filter housing, as well as eliminate the denting of the upper part of the housing when pressing with the outer figured nut.

An insert in the base of the filter housing is needed if the protrusion for fixing the base of the filter housing on your equipment does not coincide with the cutout in the base of the filter housing: the insert will cover the cutout and allow you to make it in a different place or do without a cutout at all. Attach with cyanoacrylate glue or simply press tightly into the cutout with good tension.

Air filter housing

0.2mm layer, 2 walls, 100% infill

0.2mm layer, 2 walls, 10% infill

0.2mm layer, 2 walls, 15% infill