Merlyn Automatic Wastergate Operations

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."

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

On the last page, there is a half page entitled "Information relative to
operation." It is approximately content-free. It says nothing about
how it works, how to test it operationaly to make sure it is working,
any operational limitations, etc.

Should there be some further documentation? If so, where might I get
it? I tried going to "www.Merlyn Products.com" and it does not seem to
work. Are they out of business?

-Sami
N2057M, Piper Turbo Arrow III (1978)

O. Sami Saydjari wrote:
: Should there be some further documentation? If so, where might I get
: it? I tried going to "www.Merlyn Products.com" and it does not seem to
: work. Are they out of business?

They're still around, fixing the TSIO360 installations that Piper, Cessna,
and Mooney didn't want to do right the first time. I don't think they have a
website, I think I found their number through mooneypilots.org.
--
Aaron Coolidge (N9376J)

To get answers you might give them a call:

Merlyn Products Inc
7500 W Park Dr
Spokane, WA 99224
(509)838-7500


--
-Elliott Drucker

"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
-----------------------------------------------

Thanks. I just called them. Here is what I learned.

I have serial number 30, one of the first they ever installed.
There have been several updates to the manual since the version I have;
none of them major.

The basic design has not changed since installation.

They have insufficient data on failure rates, but they have several of
them that have been operating through several engine changes without
failure.

There is a revised operating range (and chart) associated with the
wastegate that I should have.

They are sending me the updates and chart, right away, without charge.

These folks are really on top of their product and have outstanding
customer service. It was a pleasure dealing with them!

-Sami
N2057M, Piper Turbo Arrow III



wrote:

To get answers you might give them a call:

Merlyn Products Inc
7500 W Park Dr
Spokane, WA 99224
(509)838-7500

"O. Sami Saydjari" wrote in
:

The basic design has not changed since installation.

It's two tubes and a bellows. Not much to change. G

They have insufficient data on failure rates, but they have several of
them that have been operating through several engine changes without
failure.

They recommend a periodic "overhaul" if I recall, but most just ignore
it until (and if) trouble. Mine was simply moved from one engine
(during reman) to the new one. It just keeps soldiering on.

There is a revised operating range (and chart) associated with the
wastegate that I should have.

Legally, yes. But you will find it really won't tell you anything you
don't know.

These folks are really on top of their product and have outstanding
customer service. It was a pleasure dealing with them!

When I bought mine originally I was having some accessories overhauled,
including the turbocharger. Due to a really BAD (name-brand) overhaul
shop (which is now out of business), the turbo worked but not correctly.
There is a simple test of the turbo/wastegate, and my plane wouldn't
pass. Went back and forth between the two shops, trying to figure out
where the problem was.

The Merlyn folks went well above and beyond, working with me on the
problem. [And the turbocharger overhaul shop finally wound up buying me
a spanking new turbocharger, in return for my not suing in court,
complete with 8x10 glossy photos. G]

jmk