Jabiru 3300 - Reassembly - Setting The Camshaft Timing

Introduction ...

This page contains photos of a Jabiru 3300A Solid Lifter engine under going a bulk strip and rebuild. This page documents the process of setting the camshaft timing.



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Image 1

To set the camshaft timing with good accuracy we need to know when the engine is at TDC for cylinder 1. Using a dial gauge and then rotate the engine around the crankshaft axis until cylinder 1 is at TDC ...

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Image 2

We attached a copper wire to a bolt screwed into one of the sump bolts holes. Next bend this wire until the end of the wire points to the TDC marker on our home made degree wheel. As an error check rotate the engine until the dial gauge measures the piston at 0.5mm before TDC. Mark this point on the degree wheel. Rotate the engine until the dial gauge measures the piston at 0.5mm after TDC. Mark this point on the degree wheel. The mid point between the 0.5mm before TDC mark and the 0.5mm after TDC mark is a more accurate measurement of there where TDC is for cylinder 1. ....

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Image 3

Here the degree wheel pointer now points at the mid-point e.g. TDC ...

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Next rotate the camshaft until the two teeth on the large camshaft gear with dots punched in them point directly toward the crankshaft. The red arrows point toward the two dots on the large gear. Next place the thick-walled crankshaft gear on the end of the crankshaft and align it so that the single dot on the crankshaft gear is positioned exactly between the two dots on the camshaft large gear. Next use a single allen head flywheel bolt to temporarily hold the crankshaft gear in the current position on the end of the crankshaft. Do not lose this position or remove this holding bolt until you are ready to fit the flywheel properly. Clearly if this crankshaft gear gets moved accidently then timing will be lost and the engine wont run! ...

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Image 5

A close up image showing clearly the two dots on the camshaft large gear and the single dot on the crankshaft gear and where they shoud be with respect to each other when cylinder 1 is at TDC ...

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