Originally Posted by rv4bill
This is just an FYI. The owner of the first SeaRey to have a Viking engine has now had it removed and replaced with a rotax. A thrust test was performed and was said to almost equal to an 80 hp 912. Total engine package came in 30 lbs heavier than 912 set up
I'm Switzerland (neutral) or Missouri (show me) on the Viking. I'm not convinced, but I'm holding judgement for more data.
One thing I will say is that when people tout thrust measurements, they need to provide a lot of information before the thrust number tells you much.
One manufacturer could take an 0-360, gear it down, turn a big prop at low RPM and generate a huge amount of thrust that is useful in low speed applications. In fact, that's what Robinson does to power the R-22 helicopter.
Alternately, you could take the same engine, put a relatively small, high pitched prop on it, and its static thrust would be pitiful in comparison to the R-22. But that combination would make most RV's fly very well.
So unless we know the comparable prop diameters, blade count, pitch, etc., a thrust comparison may not tell us much.