Jabiru 3300 - Cylinder Barrels - Honing and Cross-Hatching

Introduction ...

This page contains photos of a Jabiru 3300A Solid Lifter engine having it's cylinder barrels honed and cross-hatched.



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Image 386

The inner surface of the barrels on this particular engine showed signs of glazing. There was also a fine lip at the end of the barrels at the point the piston would have travelled at TDC. If this lip indicates ovaling of the barrel then the barrels must be re-bored. See the overhaul manual for acceptable limits of wear. Measurement of the internal diamter off these barrels revealed that these didn't require re-boring but the fine lip needed to be rmoved and the also the glazed running surface ...

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Once the glazed surface had been removed the homing stones can be taped up (with gaffer tape or similiar) at one end so the only surface of the honing stone that can effectively work on the cylinder surface is at the end of the cylinder where the lip is. This avoids unecessary removal of barrel material from the middle of the barrel when we are really only interested in working out a mild lip at the top of the barrel. Again use plenty of cutting oil and the cylinder hone only needs to rotate at slow RPM's. Keep checking on progress at regular intervals throughout the process ...

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Once honing is complete we can use this crosshatching tool to create a fine crosshatch pattern on the inside surface of the cylinder barrel. Cross hatching is very important as a fine layer of engine oil is retained in the crosshatch grooves to keep the barrels lubricated even during the down stroke. The oil scavenger piton rings cannot remove excessive oil from the crosshatch grooves so the barrels always remain lubricated. Use lots of cutting oil with this tool. It is quite agressive so again low speed of rotation is the order of the day and a 45 degree crasshatch is desired so move the tool in and out of the barrel to achieve this ...

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When you are finished remove all traces of oil and residue from the crosshatching process before proceeding with the build ...

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