Take a step ...
and boost economic efficiency and availability of your Diesel engines
Rejuvenation At modest cost, almost all engines ever built according to MAN
for older engines design can benefit!
Applicable to all your older four-stroke engines with one-part cylinder
liners from 40/45 to 58/64.
No replacement of pistons necessary – you can have the step turned
in your old pistons at every properly equipped workshop.
a) Stepped cylinder liner in two parts for the current engine range
b) One-piece stepped cylinder liner as a replacement for 40/45 to 58/64
engines
x) Zone of cylinder liner diameter smaller than nominal and stepped–back
piston crown. The clearance is not affected. The cylinder liner has a
coating of wear-resistant material in the zone “x”.
Fig 1. Comparison of cylinder liner and piston types
Advantages Our budget-price alternative guarantees:
Amortization in less than two years by reduced lube oil consumption
alone
Constant oil quality during this period
Improved wear behaviour by elimination of bore polishing
Extension of maintenance intervals.
Overleaf, you will find the results of a long-term test with one-part stepped
liners installed in six engines of the Queen Elisabeth II.
MAN B&W Diesel Aktiengesellschaft P.O. Box 10 00 80 86135 Augsburg/Germany Phone ++49 821 3 22–0 Fax ++49 821 3 22 33 82
!
Lube oil consumption Average savings of 0.5 g/kWh compared to conventional liners, hence
pay-back period of less than 2 years for the conversion to stepped
liners.
Lube oil consumption remained constant over the total operating time.
Consumption did not exceed the newly guaranteed limits.
Lube oil quality Characteristic values of lube oil unchanged.
Viscosity and contamination remained within the normal range.
Fig 2. Lube oil consumption
MAN B&W Diesel Aktiengesellschaft Postfach 10 00 80 D–86135 Augsburg Telefon (08 21) 3 22–0 Telefax (08 21) 3 22 33 82
2
Wear values of pistons and rings Pistons normally coked, no peculiar features
Wear values of piston rings (chromium-ceramic) between 0.01 and
0.015 mm/1000 h, i.e. 50% better than the original version
TBO for piston removal extended to 20,000 hours.
Wear values of cylinder liner No bore polishing, not even wear scores and traces (max. wear of
0.004 mm/1000 h).
Cylinder liner perfectly round, especially the upper part.
Fig 3. Cylinder liner old design (approx. 10,000 operation hours)
Fig 4. Stepped liner (approx. 13,200 operation hours)
Longer service intervals due to the conversion to stepped liners and
pistons will provide additional financial advantages for the operator!
SM/TKU
MAN B&W Diesel Aktiengesellschaft Postfach 10 00 80 D–86135 Augsburg Telefon (08 21) 3 22–0 Telefax (08 21) 3 22 33 82
