(Jacob Rumans) #1

The first jobIhad to do was to strip
expecting some trouble!Irememberedthe
forcerequired to stripaZ1crankshaft
whenIwas making myKawasaki Z1600
V8 over20years ago, it stretched the
limits of myhydraulicpress andIwasn’t
looking forward to it. The first thingIhad
to do wasmakeacouple of support bars
from high tensile steel that fit between the
webs, making themasthick as possibleto
take theload required topress the
crank-pinsandjournals from thewebs.I
had alength of 30mm squareEN16 steel
bar thatwas ideal, soIcut of ftwo bits
aboutafoot long, but they would need
reducing to 23mm thickint he centre
using mymilling machine,sot hatthey
would fit in thegap between thewebs.
With th esupport bars machined I
offered up the crankshaftfrom unde rthe
pressuntilthe first webwas proudoft he
supportbars andIcould slidethem into
place ready to press out the first crank-pin.
To do thisIneededasuita ble pushbar
that was slightly smaller in diameter than
the 29mm Z1 crank-pin.Ihave abox of
old crankpinsthatIkeep for this purpose.
The push barwas thenplaced on to the
end of thecrank-pin andthenIpumped
up thehydraulic press untilthe ram
touched thepushbar an dresistancewas
felt.AtthispointIhad agood check to
make sure thecrankshaftwassitting
square, then started to pumpupthe
pressureint he hydraulic system. two tons,
five tons, eight tons,then at ninetons,

Pressing the second web from the
main journal.

Crankshaft parts ready for cleaning and assembly.

Setting web at 120 degrees on lathe. Webpress ed on to main journal.

with ahuge ‘Bang’, the first big-end
journal suddenlymoved acouple of mm
below theoutersurface oftheweb.
Great,Ithought,fromnow onthis one
will be easier.Istarted to build up
pressureagain,and sure enough at around
seven tons it movedagain, andafte rafew
more pumps of the lever the first webwas
free along with the first connecting rod.
The process was repeated on the outer

four websoft he crankshaft. Theinnerfour
webs on the firstcrankshaft could remain
assembledwith the two inner connecting
rods becauseIwoulduse this for the inner
portion of my newcrankshaft.With the
first crankshaftstrippedIhad to
completely stripasecond crankshaft so
thatIcould pick therequired webs and
two additional connecting rodsrequired for
the new six-cylinder crankshaft.
Free download pdf