cmm
Pressing Times!
Our Allen getshimselfpressedinto actiontos ort outhis crankshaft.
AllenMilllyard
Award-winning motorcyccle engineer!
d
T
he disassembly andassembly of a
pressedupmulti-cylinder
crankshaftisconsideredbymany to
beaspecialist job,carried out behind
closed doors with mystique and intrigue,
but it’s actually quite an easy job to do at
homeifyou haveafew bits of basic
engineering equipment.
With th ecrankcases finished,it was
time to start adaptingastand ard four-
cylinder Z1crankshafttofi tmynew
six-cylinder engine. The standardZ1
crankshaft isapressedup design made
from eighthardenedsteel webs anda
central shaft containing the cam-chain
drive sprocket. The webs vary inshape and
purpose. Oneweb incorporates theprimary
drive gear; four websincorporate big-end
journals; andthe other fourwebs
incorporate the main bearing journals.
There are sixrollerbearingsthatrun
directlyont he hardened main journals
and thehardened outer ringsofthe roller
bearingslocate in thecrankcases with
pegstoa lignoil feed holes.The standard Kawasaki Z1 crankshaft ready to strip.Hydraulic press with crankshaft
separation bars and push rod.Pressing the first big-end journal from
the first web.52 /classic motorcyclemechanics