How to identify investment cast Millennium cylinders

I've left a phone message with the helpline at Superior and have no idea how long it will take to get a return call, but the good news is that this forum has seldom, if ever, left me hanging with a question and no answer.

The engine on my RV-6 was overhauled by the builder, so when I was asked by someone if the Millennium Cylinders installed new during the major overhaul are investment cast, I haven't a clue.

I do know, however, that they are P/N 36000N-A20P, with S/Ns 36N-F97 1653, 1659, 1651, and 1654.

Perchance does someone know if this information identifies whether or not these power assemblies are investment cast?

Thanks,

Tosh

Tango Mike said:

I've left a phone message with the helpline at Superior and have no idea how long it will take to get a return call, but the good news is that this forum has seldom, if ever, left me hanging with a question and no answer.

The engine on my RV-6 was overhauled by the builder, so when I was asked by someone if the Millennium Cylinders installed new during the major overhaul are investment cast, I haven't a clue.

I do know, however, that they are P/N 36000N-A20P, with S/Ns 36N-F97 1653, 1659, 1651, and 1654.

Perchance does someone know if this information identifies whether or not these power assemblies are investment cast?

Thanks,

Tosh

Click to expand...

I am interested to hear the answer, I thought all barrels were forged steel blanks that were fully machined. Forged for fatigue strength.

Investment cast?

When I Googled investment versus standard cast Millennium cylinders, the first link that came up was to this forum with the typical well-reasoned replies to the question of whether the extra cost for investment cast was worth it. This issue may be best categorized as belonging to the never-ending debate section, but after reading a bit, I went from knowing nothing about the topic to at least understanding that a difference exists, and the added value of it versus the extra cost is a matter of variable opinion.

Not sure if this is what you're looking for but below is a copy of the Superior cast cylinder assembly AD.

AD 2007-04-19 R1

EFFECTIVE DATE

(a) This airworthiness directive (AD) becomes effective May 7, 2007.

AFFECTED ADS

(b) This AD revises AD 2007-04-19.

APPLICABILITY

(c) This AD applies to Superior Air Parts, Inc. (SAP), cylinder
assemblies, manufactured between April 2005 and November 2005, part
numbers (P/Ns): SA47000L-A1, SA47000L-A20P, SA47000S-A1, SA47000S
-A20P, SA47000S-A21P, SA52000-A1, SA52000-A20P, SA52000-A21P, SA52000
-A22P, SA52000-A23P, SA55000-A1, and SA55000-A20P, installed in
Teledyne Continental Motors (TCM) 470, 520, and 550 series
reciprocating engines. These P/N cylinder assemblies may be installed
in the TCM engine models listed in the following Table 1.

ILLUSTRATION (Table 1)

These engine models are installed in, but not limited to, the aircraft
models listed in the following Table 2:

ILLUSTRATION (Table 2)

This AD also applies to SAP, cast cylinder assemblies, P/Ns SL32000W-A1,
SL32000W-A20P, SL32000W-A21P, SL32000WH-A1, SL32000WH-A20P, SL32006W-A1,
SL32006W-A20P, SL32006W-A21P, SL36000TW-A1, SL36000TW-A20P, SL36000TW
-A21P, SL36000TW-A22P, SL36000W-A1, SL36000W-A20P, SL36000W-A21P,
SL36006W-A1, SL36006W-A20P, and SL36006W-A21P, installed in Lycoming
Engines (LE) 320, 360, and 540 series reciprocating engines and Avco
Lycoming 540 series reciprocating engines. These P/N cylinder assemblies
may be installed in the LE and AL engine models listed in the following
Table 3.

ILLUSTRATION (Table 3)

These engine models are installed in, but not limited to, the aircraft
models listed in the following Table 4:

ILLUSTRATION (Table 4)

These engine models are known to be installed in the aircraft models
listed in the following Table 5:

ILLUSTRATION (Table 5)

UNSAFE CONDITION

(d) This AD results from comments from the Public on the existing AD. We
are issuing this AD to prevent cylinder separation that can lead to
engine failure, a possible engine compartment fire, and damage to the
airplane.

COMPLIANCE

(e) You are responsible for having the actions required by this AD
performed within the compliance times specified unless the actions
have already been done.

DETERMINING WHICH CYLINDER ASSEMBLIES ARE INSTALLED

(f) If aircraft engine records do not list the P/N of the cylinder
installed during engine overhaul or repair, visually inspect the
cylinders. The affected SAP cylinder head barrel flanges are marked:
SA47000L-A1, SA47000L-A20P, SA47000S-A1, SA47000S-A20P, SA47000S-A21P,
SA52000-A1, SA52000-A20P, SA52000-A21P, SA52000-A22P, SA52000-A23P,
SA55000-A1, or SA55000-A20P or SL32000W-A1, SL32000W- A20P, SL32000W
-A21P, SL32000WH-A1, SL32000WH-A20P, SL32006W-A1, SL32006W-A20P,
SL32006W-A21P, SL36000TW-A1, SL36000TW-A20P, SL36000TW-A21P,
SL36000TW-A22P, SL36000W-A1, SL36000W-A20P, SL36000W-A21P, SL36006W
-A1, SL36006W-A20P, or SL36006W-A21P.

CYLINDER ASSEMBLY REMOVAL

(g) Remove all cylinder assemblies with a serial number of 47LE053559
through 47LF053643, or 47SE054212 through 47SF054251, or 52D0531708
through 52H0532197, or 55E05223 through 55G05289, or 32WE059006
through 32WF059067, or 32WHE05379 through 32WHE05392, or 326WF055517
through 326WF055532, or 36TWF05430 through 36TWG05453, or 36WF058058
through 36WG058124, or 366WE056944 through 366WF057061, or 366WF057150
through 366WF057232, or 366WF057259 through 366WG057534, or
366WG057556, 366WG057569, 366WG057598, 366WG057616, 366WG057621,
366WG057624, or 366WJ057770 through 366WJ057776, or 366WL058131 no
later than 150 hours total time-in-service (TIS) to preclude cylinder
head fatigue failure and separation at the head-to-barrel threaded
interface.

(h) For cylinder assemblies with more than 150 hours total TIS on the
effective date of this AD, a 10 hour TIS extension is permitted for
the purpose of flying the aircraft to a location where maintenance
action can be done to meet the requirements of this AD.

(i) After the effective date of this AD, do not install any cylinder
assemblies with P/Ns SA47000L-A1, SA47000L-A20P, SA47000S-A1,
SA47000S -A20P, SA47000S-A21P, SA52000-A1, SA52000-A20P, SA52000-A21P,
SA52000 -A22P, SA52000-A23P, SA55000-A1, or SA55000-A20P,or SL32000W
-A1, SL32000W -A20P, SL32000W-A21P, SL32000WH-A1, SL32000WH-A20P,
SL32006W-A1, SL32006W-A20P, SL32006W-A21P, SL36000TW-A1, SL36000TW
-A20P, SL36000TW -A21P, SL36000TW-A22P, SL36000W-A1, SL36000W-A20P,
SL36000W-A21P, SL36006W-A1, SL36006W-A20P, or SL36006W-A21P with a
serial number of 47LE053559 through 47LF053643, or 47SE054212 through
47SF054251, or 52D0531708 through 52H0532197, or 55E05223 through
55G05289, or 32WE059006 through 32WF059067, or 32WHE05379 through
32WHE05392, or 326WF055517 through 326WF055532, or 36TWF05430 through
36TWG05453, or 36WF058058 through 36WG058124, or 366WE056944 through
366WF057061, or 366WF057150 through 366WF057232, or 366WF057259
through 366WG057534, or 366WG057556, 366WG057569, 366WG057598,
366WG057616, 366WG057621, 366WG057624, or 366WJ057770 through
366WJ057776, or 366WL058131 into any engine.

ALTERNATIVE METHODS OF COMPLIANCE

(j) The Manager, Special Certification Office, FAA, Rotorcraft
Directorate, has the authority to approve alternative methods of
compliance for this AD if requested using the procedures found in 14
CFR 39.19.

SPECIAL FLIGHT PERMITS

(k) For aircraft with engines that have between 140 hours and 150 hours
TIS only, special flight permits may be issued in accordance with Sec.
Sec. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR
21.197 and 21.199) to operate the aircraft to a location where the
requirements of this AD can be done. Special flight permits may not be
issued for aircraft that have utilized the provisions of paragraph (h)
of this AD.

RELATED INFORMATION

(l) Superior Air Parts, Inc. Mandatory Service Bulletin B06-01, Rev. E,
dated January 24, 2007, contains information related to the subject of
this AD.

(m) Contact Jurgen Priester, Aerospace Engineer, Special Certification
Office, FAA, Rotorcraft Directorate, Southwest Regional Headquarters,
2601 Meacham Blvd., Fort Worth, Texas 76137; e-mail:
[email protected]; telephone (817) 222-5159; fax (817) 222
-5785 for more information about this AD.

MATERIAL INCORPORATED BY REFERENCE

None.

Issued in Burlington, Massachusetts, on March 23, 2007. Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft Certification
Service.

FOR FURTHER INFORMATION CONTACT: Jurgen Priester, Aerospace Engineer,
Special Certification Office, FAA, Rotorcraft Directorate, Southwest
Regional Headquarters, 2601 Meacham Blvd., Fort Worth, Texas 76137; e
- mail: Jurgen.E. [email protected]; telephone (817) 222-5159; fax (817)
222-5785.

The AD isn't the issue

The AD doesn't apply to these cylinders. That question was asked and answered last year. I'm just trying to find out if these are investment cast. It's not going to be easy to do, apparently.

I can tell by looking. Hard to describe but the investment cast heads are smooth looking and the sand cast ones aren't. That help?

aerhed said:

I can tell by looking. Hard to describe but the investment cast heads are smooth looking and the sand cast ones aren't. That help?

Click to expand...

Yes, after looking, it is the heads that would be investment cast, not cylinders (barrels). The surface of a sand cast fin looks like sandpaper in places, i.e. sand. You will still see it in the casting. It is especially noticeable at the centerline of the heads, like the front side of #2. The investment cast will look very smooth, everywhere. The fin cast draft is greater. It will look like they are more tapered from the base to the tip.

Thanks for this info. I'll take a look tomorrow. In the meantime, this is the best image I have of the cylinders. Don't know if there's enough detail showing for a reasonable guess.