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Old January 8th 05, 12:58 AM
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Chuck wrote:

I also saw someone else mention a replacement cowl that improved
airflow, dual exhaust (instead of muffler in front of the firewall),
and less drag. Is that what you have on your 180???


Chuck,

Your -180 is one of the earliest examples ( a "B" model, I think).
As such, it incorporated the same cowl and restrictive exhaust system
that was used on the lower power models. Beginning with the "C" model
in '65, the -180 cowl was changed to a two-piece fiberglass clamshell
type and the less restrictive dual exhaust was added. With the old
cowl and old exhaust (particularly the latter), I'm not surprised that
you see a cruise of 110 kts. That's not unusual for the earlier
models.

I suppose that you could recowl the plane with a newer version, but
you'd probably have to get some kind of official signoff for a mod like
that (i.e 337 at minimum, field approval worst case). This could be
pretty expensive for minimal returns and there might be issues fitting
the existing exhaust into the newer style cowl.

For the exhaust, Powerflow exhausts are available only for the early
model -180s. It seems that the later model stock dual exhaust was not
very restrictive and didn't warrant a specially modded pipe. If the
-180 Powerflow improvements are similar to those of the -140 with a
similar exhaust, this could improve your engine output significantly.
Of course, the downside is that it's expensive. I'd probably wait
until my exhaust system needed major work, then go with the Powerflow.
John Galban=====N4BQ (PA28-180)