A10 ROLLER CONVERSION
The Timing side crankcase: PART 1
The roller bearing used in this conversion is
an INA.NKIB 5906 C3
. It’s a combination needle /roller, ball bearing with a two part
inner race. Dimensions are 30 mm ID, 47 mm OD, and 23 mm Width. The C3
clearance allows more crush on the bearing, as its internal clearances are
larger than
The depth of the hole is 20.5 mm measured from the machined area that
the original bush sat against. The bearing rests against the step left in the
hole. It is important that the bearing when fitted covers the 2 holes, 1 from
the oil pump and the other to the oil pressure relief valve. A groove 4 mm square is machined around the
bearing to join these two holes. If this groove coincides with the BEARING oil
groove, oil pressure to the big ends will be LOST!!!
The
Timing side crankcase: PART 1
A
hole is drilled from above the bearing inside the crankcase, to meet the
bearing oil groove. A groove in the sidewall of the case forms a channel for
the oil to run. I also drilled a hole in the top web and scalloped the area to
act as a catchment for oil, much like the one for the
idler gear. The area of the case that
prevented the bush from turning must be machined flat all the way to the curved
part of the crankcase.
The Timing side crankcase: PART 1
This is the way the oil flows in this type of
conversion. From the oil pump it splits in 2,part goes through the new oil
gallery up the wasted oil pump-fixing bolt to a bridge that takes it to the
crankshaft quill and on to the big ends. The rest goes around the new 4 mm
square-bearing groove to the pressure relief valve and some is bled off to a
100 psi oil pressure gauge.
The Timing side crankcase: PART 1
Oil pressure gauge take off hole. I
used 1/8” BSP and 100 psi
Gauge
The
Oil Pump : PART 2
This
drawing is of the oil pump modifications.
Drill Hole
The Oil Pump :
PART 2
The Oil Pump : PART 2
1/ Wave washers ¼” 3 of
2/ Fiber washers ¼’’ 2 of 3/
oil pump gasket same thickness as D
A/
Top hole for bolt F that passes through bridge G
B/ Bottom hole for bolt H.
C/ forward hole for bolt I that passes
through bridge G
D/ Oil pump gasket, top hole larger to go
over spigot,
E/ See oil gallery parts drawing above.
F/ Top hole wasted bolt. Allen head cap
screw head machined 45 deg. Under head 5 mm machined at 45deg. to 3 mm dia. Total length under head 60 mm last 15 mm threaded.
G/ See crankshaft end feed bridge above.
H/ Allen head cap screw 45 mm under head.
I/ Allen head cap screw 55mm under head.
Exploded view of oil pump and bridge.
The Crank :
PART 3
The crankshaft is machined to a diameter of
1.180 inches [the same size as the Drive side] all the way to the web leaving a
small radius. The threaded part of the crank is machined to a length of 29 mm
measured from the end of the crank to 1st step. A 3/16’’ hole is SLOWLY drilled
through the end of the crank till it breaks into the original oil gallery. Then
a 1/4’’ hole 9mm deep is drilled to accept the quill. The S/S quill
is 20 mm in length with a 3/16’’ hole through the center. There is
a 8mm section with an OD of .002’’larger than ¼’’ which
is pressed into the end of the crankshaft. The rest of the quill is
3/8’’ OD un machined. The crank must be well supported when
pressing the quill home. After the quill is pressed home it is machined to a
final OD of 8 mm. From the end of the quill to the 1st step is 12
mm.
In the pictures below
the split inner race can be seen on the crank. What are not so obvious are the
shims [same type as drive side] behind 
the race (must
clear the radius M with the shims), which positions the crankshaft central in
relation to the bores . This must be done BEFORE the drive side bearing is
shimmed to allow for crankshaft expansion. I give the drive side bearing
.010’’
The Crank : PART 3
After shimming the crank you will have to make the spacer that goes
behind the crankshaft timing gear, which locks every thing together. This is
done by measuring the distance between the end of the inner race and the back
of the crank gear after it has had the back ground flat.
A/ Spacer: OD = 40 mm ID = 30.25 mm Width = To
be determined, see above.
B/ Crank gear 67-0339 Must be reduced in
thickness to 15.5 mm. Material is to be ground off the backside of the gear.
C/ Washer Part# 67-0645
D/ O/P worm gear 67-0642 = 1mm must be ground
off the hex end of this gear.
E/ Lock washer Part# 67-0644
F/ Left hand nut Part # 67-0643 Must be reduced
in thickness to 3 mm.
Notes.
Don’t forget to clean/check the pressure relief valve
I Made no changes to the ant-siphon valve in my conversion
A10 Roller conversion as described by Beeza Bill http://www.geocities.com/beezabill/ with small amendments I found may help. Andrew Luckman
Any modifications done using this information is done at your own risk