"Everyman's Jet Engine" - Why Valveless Pulsejets? No lubrication of any kind needed Since we have no moving parts, and therefore no close-fit sliding bearing surfaces, there is absolutely no need for lubrication (this is true of valved pulsejets, too, of course). So, we don't need oil mixed with liquid fuels (though oil has itself been used as a pulsejet fuel!) and we don't need external pumps and the heavy power sources they require. This is just one less detail we have to worry about in the design, building and running of our engines.