Richard Riley wrote:

I've heard the same thing (though the version I've heard was certified
engine *and prop*)

Like you say, it's *supposed* to be 25 hours for a certified
engine *and* *prop*, but there seem to be a lot of cases
where a certified engine alone gets you 25 hours. I also
know of at least one case where a non-certified engine got
25 hours. Like everything else, it depends on the inspector.
Personaly, I can't imagine feeling done after 25 hours. I've
got at least 50 hours planned, and that would apply regardless
of what engine and prop I used...but I can see the utility of
being able to leave the flight test area with less. I've got
a certified engine (an O320-D2C, apparently THE O320-D2C)
and experimental prop (Aymar-Demuth). I'm also slow as
molasses and only have about 5 hours on the airplane so far.

I comply with all the engine AD's I can, or at least take them as
serious warnings. Not because they're required, just because they
might be good ideas.

Same here on all counts.

Dave 'creeper' Hyde
RV-4 Builder, EAA Tech counselor