"O. Sami Saydjari" wrote in
:

I believe I have a Merlyn Automatic Wastegate. In looking through the
documentation I got with my airplane (PA28R-201T), I found something
entitled "Merlyn Products, Inc. Upper Deck Pressure Control for the
Teledyne Continental TSIO-360-F and -FB Engine; Installation Report:
Number 18-1; August 3, 1989."

Yep... That's it. You should have TWO pieces of information in order to
be completely legal.

#1: The STC for the installation.
#2: The amendment to the POH for operations.

And, of coursre, the appropriate logbook entries.

Is this supposed to be the manual for the automatic wastegate? Is
this just another name for a wastegate?

Again, yep. The original "wastegate" for that plane was nothing more
than a bolt screwed into a pipe part way. Like most compromises, it
didn't work well at anything. At low altitude your turbocharger still
had to produce boost, increasing heat and stress. At high altitude half
your boost was being dumped overboard, limiting your high altitude
performance. [It does have two advantages. Being a bolt, it's cheap,
and it is reliable. G]

The Merlyn wastegate replaces the bolt with a bellows arrangement that
adjusts in and out as needed. At low altitudes it will only produce
boost at high power settings. At high altitude,... well, it adds
another 5,500 feet to your critical altitude. It also reduces by about
half your throttle setting sensitivity to altitude, and cuts down
somewhat on bootstrap problems. Good stuff.

Due to FAA limitations, the POH amendment is nothing more than the same
[power vs. RPM vs MP] chart, with the numbers replicated on down the
page.

-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
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