How strong is the maximum so-called throttle valve?

Hello everyone, sometimes a general question – how strong can the so-called petrol or diesel become if one would suddenly close the intake area? I ask for that, because I just want to know if one could choke off every motor by air, but with the closing of the intake tube only with the bare hand, or if there are motors, where one should not do it, because the so-called too strong and the hand would suck in or break down. Is there a strong underpressure?