Wear n values

CONSUMPTION
f.o 170g/kwhr
Sys oil 0.15g/kwhr
Cyl oil mech- 1-1.5 and alpha 0.7g/kwhr
 

Compression ratios

Min comp ratio 12.5-13.5
Slow speed 2stroke 12:1
Med speed t/c 4stroke 12:1
High speed natural 4s 23:1
Emcy gen 14:1 to 16:1
Lifeboat engine 23:1

Main n Crankpin surface roughness 0.8Ra n reconditioned @ 1.6
Crosshead pin 0.05Ra n repolish @ 0.1Ra

Liner wear
0.05mm/1000hrs for slow 2sfroke and max wear is 0.4-0.8% of dia. Max ovality is 1mm.
0.015/1000 for Med 4stroke

Piston
Rings wear 0.1mm/1000hrs
Radial width 17.2mm as new and max 14.2mm
Ring height 12.4 for new ring 1 and 9.4 for new ring 2,3,4
Radial clearance 1.5-2 mm
Groove height 13.2 for 1st groove and 10.2 for 2,3,4 groove
Axial clearance 0.35-0.4mm (new).   Max 0.87mm
Butt clearance 3.4mm for ring1 for new and 2.4mm for ring2 - new
Butt is 0.4-0.5% of dia
Max free ring gap 25mm
Piston top max permissible burnaway 15mm
CPR groove min depth 1.1mm.

Piston press test 7bar.

Stuffing box
axial 0.1-0.2mm
Butt clearance 50%
Butt clearance 3-4 mm
Sealing ring total butt 4*6 mm n 639mm free length
Scraper ring total butt 3*3mm n 496mm free length.

          

                6s50MCC CLEARANCES    

CROSSHEAD

0.15-0.55 mm.      

Oil wedge length 10mm (take clearance at 45 degrees after bdc)

xhead wear limit is 50%reduction of oil wedge.
BOTTOM END BRG CLEARANCE

0.2-0.55         (take clearance @bdc)

MAIN BRG CLEARANCE   

0.3-0.65.        (90 degrees after tdc)

 Brg wear rate 0.01mm/10000hrs

THRUST BRG

new  0.5-1mm and limit max 2mm

TURBOCHARGER
Radial 0.15-0.2
Axial 0.2-0.3mm

STERN TUBE BRG CLEARANCE

Water cooled 8-12mm
Oil cooled - 1.87-2mm

PROPELLER

Propeller drop: 1mm/160mm diameter of the tail shaft (poker gauge) and taper of 1:80 given since prop acts as cantilever beam n induces Bending moment.

Brg clearance 0.51-0.63 for 300mm dia shaft

                       1.53-1.89 for 900mm dia shaft

STEERING GEAR

Jumping clearance: 3-5mm

Wear down Clearance at raphson slide mechanism: 16~19mm (trammel gauge)

Top Clearance at raphson slide mechanism: 6~9mm

Pintle clearance 1.5+0.001D    (1.1mm~3.3mm)

Riding washer clearance 10-15mm

Wear down of vane type thrust brg is 0.1mm

PUMP

Gear pp 0.1mm btw gear and housing; 0.025mm btw gear n casing covers.

Centrifugal pump wear ring clearance 0.4-0.6mm

AIR COMPRESSOR

Bumping clearance 0.5-1% of cyl dia usu 1.5-2mm

Air reservoir max Corr allowance 1.5mm for 18mm thick shell

Fusible plug at 104.4 degrees

Max allowed temp after compressor 93 degrees.