Engine Overhaul Manual
Jabiru Aircraft
Pty Ltd
Jabiru 2200 & 3300 Aircraft Engines
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Dated : 28/10/2014
Issued By: AS
Page: 73 of 201
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Take care not to scratch the base or sides of the ring lands
– this will inhibit ring sealing which may lead
to blow by and other related problems. Wash the pistons with kerosene then soapy water, rinse and dry.
Clean the cylinders thoroughly with kerosene, dry and apply engine oil or other corrosion protection to
the bores immediately.
After measuring, if a cylinder is deemed fit for re-use it should be lightly honed. Cylinders outside the
limits given in Table 10 at the mid-bore are unfit for re-use.
5.11.1.3 Inspection and repair
Note that whenever measuring cylinders or pistons measurements must be made both in the line of the
gudgeon and at 90 degrees
– as shown in Figure 83 (right). This is because wear of these parts is
usually higher in one orientation than the other.
Figure 83
– Measuring Cylinders & Pistons
Top End Overhaul / Full Overhaul:
New pistons are to be fitted.
Measure the cylinder diameters at approximately half stroke; for a top end overhaul they must not
exceed the limits noted in Table 10 to be to be returned to service. A cylinder which measures smaller
than this measurement will give 1 to 2 cycles further use if operated and maintained correctly. After
measuring, check carefully for signs of ovality: measure at 3 equally spaced intervals around the bore.
Measure the piston diameter and calculate the clearance between the cylinder wall and the piston: it
must be within the limits given in Table 12 in order for the piston and cylinder combination to be
returned to service.
If the clearance is greater outside the limits given in Table 12, new cylinders must be fitted.
During Other Maintenance:
Check the side clearance of the top 2 rings (the gap between the side of
the ring and the ring land on the piston). If the side clearance is outside the limits given in Table 12 new
pistons must be ordered.
Note that recent pistons incorporate an increased ring sliding clearance of 0.05mm to 0.10mm. Wire
circlips on the gudgeon pin were also replaced with standard 25mm ID circlips at this time. 23mm
internal circlips are also used on some engines.
Full Overhaul:
Measure the cylinder diameters at approximately half stroke; for a full overhaul they must not exceed
the limits noted in Table 10 to be to be returned to service. A cylinder which measures smaller than this
measurement will give 2 cycles further use if operated and maintained correctly. After measuring,
check carefully for signs of ovality: measure at 3 equally spaced intervals around the bore.
Measure the piston diameter and calculate the clearance between the cylinder wall and the piston: it
must be within the limits given in Table 12 in order for the piston and cylinder combination to be
returned to service.
If the clearance is greater outside the limits given in Table 12, then parts must be changed
– pistons or
cylinders
– to obtain correct clearance.
