| 12th October 2010
Upper main casting
The base has been machined to a datum
line. |
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| 13th October 2010
Here the casting has been set up for
boring between centres.
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| The base was packet with shim until
it aligned with the score marks in the "black".
Then it was set with a DTI to ensure
squareness but when checked by measurement at the cylinder head end slight
adjustment was made after the first few cuts to ensure the hole was
central.
Note
Do not think just because the side ie
running true it is fully aligned Check by measurement.
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| The boring was carried out between
centres , including the recess and then as shown here the cylinder head was
machine off at the same setting with a fly cutter to ensure the face was
square with bore. |
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| In the picture the cylinder liner
has been positions in the upper main casting.
There are still several things that have
to be done to the upper main casting so the liner will be removed and then
finally fixed in place on final assembly. |
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| 23rd October
2010
Several holes need to be drilled and
tapped in the casting.
The one for the spark plug is a M10 x
1mm pitch and the thread length of the spark plug is 8.6mm and 14.3mm Hex
size, according to information on the web. I am having to obtain the correct
tap as I only have a M10 x 1.25.
Other holes are M6 and 1/8" BSP. |
| I decided that as I did not have
a 1/8" BSP which uses a tapping drill of 8.75mm that a 1/2" British
Standard Cycle of 1/2" x 26 uses a taping drill of 11.5mm and make the water
drain hole outlet bigger so the flow would be quicker.
The oil way hole which is to be made
down from the top and into the cylinder liner I have had to make up an extension
to a 5mm drill and also for the M6 tap.
The completed drill is show but the tap
has yet to be inserted into it holder.
Also today the top was machined flat
an parallel to the base.
Whilst a bung has been made in bras it
is likely that this will be changed to Stainless Steel. |
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| 17th October 2010
At the Warwickshire Show I was able to
see the recess that is needed for the spark plug to sit upon. This is not
a deep recess but it is threaded all the way through.
You can see that the spark plug is may
5mm above the line to the other tapped holes something not clear on the
drawings. |
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| 2nd November 2010
I wish I have noticed that the spark
plug hole in the picture above is not as on the drawing and then another
procedure would not have been as difficult.
This is there set up used to drill and
tap the M10 x 1mm hole.
The laser pointer was used to find the
exact location as per the plans by location and edge and then using the DRO
to guide the point the correct distance.
The tap is supported by the pointed centre
held in the drill chuck to ensure a vertical tapping. |
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| Next the very tricky bit.
There was no way to hole the upper main
casting in the mill as there is insufficient height. So I decided to drill
the tap hole for the cylinder head by hand.
The problem to over come was the close
proximity of the hole of the plug and one of the stud holes.
Careful checking resulted in deciding
that all was well there was enough room.
The hand held battery drill was used
and a mark pout on the drill to indicate the depth required.
After drilling the hole they were all
taped using the normal procedure. After the cylinder head had been used as
a guide the holes were drill out to 6.5mm as clearance holes for the studs
using the pillar drill. |
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| So here is the result and very nearly
completed upper main casting. The cylinder head has been trail fitted and
it does slide on and down to the liner.
The gasket has not yet bee cut but it
will be soon. |
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TO BE CONTINUED
