Hurant Karibian wrote:

The turbo compound was designed to cause no back pressure in the

exhaust

system, using velocity instead so there was no waste gate. They

produced

450

HP,

combined at takeoff power, or 150 HP each.

BTW Hurant you are much better pilot than I. I average 500 hours

per

exhaust valve

on my O-470.

Paul Lamar

Harrison Young wrote:

That's very possible. My Baron has two IO-470's with nearly 1500

hours

each.

No cylinders or exhaust valves have been replaced during that

period.

Harrison Young

I guess you are a better pilot than me as well Harrison. Anybody else

out

there want

to chime in? :)

BTW how fast do you cruise that gas hog? :)

Paul Lamar

Harrison, Paul,

care to compare how you operate your engnies?

EGT, manifold pressure, rpm, etc.    ..... maybe we learn something! :)

Thomas J.

Well I will lean mine using the EGT scanner at altitude cruise and then

forget to

readjust the mixture when I descend :) Since I got a flow meter now that

is a far

more accurate way of adjusting the mixture.

Paul Lamar

Harrison Young wrote:

Thomas,

As far as operation, I run anywhere from 45% to 75% power depending on where
I'm going, and how much of a head wind I have. Most of the time I run at
65%, which is 2300RPM and 24" MP for the Baron. With two exceptions I do
everything strictly by the book.

The first exception is that I lean a lot more than the book says during
climb. I started doing this after reading a lot of info which convinced me
that the deposits created by running excessively rich are more damaging than
running lean during a climb. You can find some good info about that on the
sky ranch website. When climbing out from 1,500' here in Phoenix, I lean to
about what the book recommends for 5,000' and continue to lean as I climb. I
lean for about 150 degrees rich of the sea-level 75% peak EGT.

The second exception is that regardless of cruise altitude or cruise power
settings, I lean to about 50-75 degrees rich of the sea-level 75% peak EGT.
I figure if the engines can run all day at sea level at 75%, then they
should be able to withstand that same EGT at any other altitude or power
setting. Much of the time if I am at higher altitudes or lower power
settings this means I am actually leaning to PEAK EGT instead of being rich
of peak, because I still don't reach the sea-level 75% EGT.

I don't have any fancy engine monitor, just a couple of old-fashioned analog
EGT gauges.

I am not recommending these procedures to anyone, but it has worked for me.

Paul,

As far as cruise speed, it takes about 27GPH to go 190 knots. The term "Gas
Hog" is very relative when talking about airplanes. For a while I was buying
fuel for a jet which burned 200GPH to go 380 knots. This makes the Baron
seem down right ecunomical :)

Harrison Young

 
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