Finished Intake system
Trog’s air intake and filtration system is a somewhat flawed design. The plastic air filter box sits right above the carburetors. After Trog is turned off, there is a little bit of gas remaining in the carbs. This gas evaporates and soaks the air filter. In the event of a fire or backfire this is ready fuel (to quickly light the plastic air filter box). When the Swedish military renovated their fleet of TGBs they added a new metal air filter box further upstream in the intake system and just used the old air filter box as a manifold to feed the carbs.
I have been wanting to make the same mod to Trog, but have had trouble finding a suitable air filter box. I finally found one off a mid 90s Jeep Wrangler with a 6 cylinder engine, same as Trog, so it should be sized appropriately. Plus, this means that air filters are easy to come by. Most auto parts stores don’t stock the correct filter for the old filterbox.
The air path goes thru the new filter box behind the passenger and up thru a stainless tube to an intake box. A vent plate finishes the outside. I believe the vents will alllow enough air in (their combined area is almost the same as the diameter of the intake hose). If not, I will replace the vent plate with something with larger orifices.
The old route was thru a bit of flexible tubing with an intake just in front of the radiator. This took up some room in the engine tunnel and I found it somewhat untidy looking, as well as possibly prone to water intake.