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MC Engine Service Experience: Exhaust Valve Bottom Piece MC/MC-C - 1997

The document discusses the development and performance of new exhaust valve designs for MC engines. It introduces the W-SEAT design which replaces the traditional chamber seat. Test results showed the W-SEAT significantly increases time between overhauls by lowering temperatures in critical areas and crushing carbon particles. The W-SEAT can be used on all MC engines and its simpler design lowers costs while improving durability. A modified bottom piece design with a second sealing groove is also introduced to further enhance performance.

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Aleksandar Sasa Seferovic
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© © All Rights Reserved
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1K views9 pages

MC Engine Service Experience: Exhaust Valve Bottom Piece MC/MC-C - 1997

The document discusses the development and performance of new exhaust valve designs for MC engines. It introduces the W-SEAT design which replaces the traditional chamber seat. Test results showed the W-SEAT significantly increases time between overhauls by lowering temperatures in critical areas and crushing carbon particles. The W-SEAT can be used on all MC engines and its simpler design lowers costs while improving durability. A modified bottom piece design with a second sealing groove is also introduced to further enhance performance.

Uploaded by

Aleksandar Sasa Seferovic
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
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MC Engine Service Experience

Exhaust valve bottom piece MC/MC-C – 1997

Cooled steel

Engine
types:

26MC
35MC
42MC
Alloy 50

Semi cooled steel


(Hardened seat)

46MC-C
50MC+MC-C
60MC+MC-C
70MC+MC-C
80MC+MC-C
90MC+MC-C
Min. 500 HV (20)

L/1260-3.0/1197
Design and Experience

90MC Modification of exhaust valve


Double "knife" seat

L/7831-6.0/0697
News from MAN B&W Diesel

W-SEAT enhances durability of


MC exhaust valves
7 February 2001

In the mid-1980s, MAN B&W intro- Now MAN B&W Diesel A/S introduces The material selected for the W-SEAT
duced the well-known chamber seat the W-SEAT as a replacement for the is a solid low alloy steel which is induc-
on exhaust valves. During the past 15 chamber seat. The W-SEAT has been tion hardened on the seating surfaces.
years this design has resulted in signifi- developed during several years of re- Hence the welding of costly hard
cantly increased search and tests with the aim of increas- facing material is avoided, yielding a
ing the time between overhauls considerable cost advantage. The in-
even further. troduction of this cost-effective pro-
duction method has made it possible
Very positive results to reduce the price and simultaneously
have been increase the expected time between
achieved during overhauls, as well as significantly ex-
these tests with tend the expected total number of
the new ge- hours in service.
ometry of the
W-SEAT, The W-SEAT can be used on all types
which re- of MC engines, regardless of the
tains the spindle type.
tempera-
ture re-
ducing MAN B&W Diesel A/S
features of Copenhagen
the cham- Information Dept.
ber seat and
combines
them with two
narrow
concentric
contact areas.
The effect is that all car-
times between overhauls bon particles which happen to be
thanks to a lowering of the temperature trapped between the spindle and the This News Release is also available at
level in the seat material in areas adja- bottom piece will be crushed and the Internet address: www.manbw.dk
cent to the exhaust gas passage. squeezed out and therefore eliminated under ‘Libraries’, ‘News’, from where it
without giving rise to any appreciable can be downloaded. Pictures can be
dent marks. downloaded in printable quality.

Page: 1 of 1 (No. 01/2001)


S50MC-C Exhaust Valve

Spindle Seat with typical Bottom Piece


Burn Marks

MAN B&W Diesel A/S


L/0000-0.0/0000
Service Experience

Performance of fuel valve

Conventional valve

MAN B&W Diesel A/S


Slide valve
(890 h after installation)

M/V Don Juan 8S60MC


exhaust valve, cylinder 2

L/71259-6.0/1000 (3210/PYJ)
S50MC-C Exhaust Valve

Bottom Piece with W-Seat Corresponding Spindle Seat

MAN B&W Diesel A/S


L/0000-0.0/0000
MC Engine Service Experience
Exhaust valve bottom piece MC/MC-C new from 2001
Cooled steel Cooled steel
Original design Modified design
(welded hard facing) (Hardened
W- seat)
Engine types:
26MC
35MC Alloy 50
42MC Hard facing

Semi cooled steel Semi cooled

MAN B&W Diesel A/S


(Hardened seat) steel
(Hardened
46MC-C W- seat)
50MC+MC-C
60MC+MC-C Hardening
70MC+MC-C zone
80MC+MC-C
90MC+MC-C

L/71 446-5.0/0201 (afdeling/ID)


Design
Exhaust Valve -
Small/medium bore

New seal for


bottom piece
lower groove

MAN B&W Diesel A/S


L/70562-1.1/0400 (2300/UM)

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