I love this discussion, keep it up guys! Blowing holes in "hangar talk theories" is important. I was led to understand that there are prop limits for the 0200 and 0200 crank STC that limit the potential for higher speed they could offer, is that correct? Also, I understand the 0200 installation is quite a bit heavier, how much more than a C85 stock engine does the 0200 crank STC engine weigh?
.--- In [email protected], "bigbrownpi...@..." <bigbrownpi...@...> wrote: > > Ed, > > My thinking is that there may be a small increase in fuel consumption, but > not much. First, the O-200 rorating assembly is stroked, so it is a 201 > c.i.d. vs. a 188 c.i.d. The engine is not working as hard as a C-85 at the > same RPM; it's putting out more torque than a C-85 at the same RPM. Second, > it's higher compression. Third, the O-200 recommended 75% cruise speed is > 2500 RPM, so I would expect that whatever the O-200 fuel economy is, I would > see the same. The only thing I haven't accounted for is the different cam > profile between the C-85 and O-200. I will be keeping the C-85 cam as far as > I know. So any increase in fuel consumtion should be from the increase in > parasite drag, and from the greater displacement engine; kind of the same way > that the 6.0 liter LS-2 engine uses more fuel than the 5.7 liter LS-1. (I > think!) > > Dave > > --- In [email protected], "Ed Burkhead" <ed@> wrote: > > > > > > Dave wrote: > > > I'm getting 107.95 at 2500 RPM with a 7148. > > > That's with the 5% loss. Certainly seems > > > realistic for the C-85/O-200 STC engine. > > > > > > Right > > > > Flying at 2500rpm instead of 2400rpm, gets you almost four extra mph. > > > > I'd also want to figure the increase in fuel consumption. If extra speed > > makes you do an extra fuel stop, you've lost all advantage of the greater > > speed. > > > > In many cross country flights, I've increased my total speed by slowing down > > to 90 or 85 or so and, by getting better fuel economy, I've been able to > > safely bypass a fuel stop. > > > > Taking all this into account adds to the mental > > brain-all-involved-and-active aspect of flying that I love. > > > > Ed > > >
