Jabiru 3300 - Reassembly - Preparation and Joining of the Crankcase Halves

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 preparing the crankcase halves for rejoining.



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Having inspected the crankcases for any obvious damage e.g. evidence of fretting etc. and measured critical dimensions as per the overhaul manual we can prepare the crankcases for rejoining. Make a start by replacing all the pushrod tube o-rings. Carefully prise the old ones out with a hooked pick or smiliar implement ...

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Clean o-ring grooves ...

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Clean out the o-ring groove and then spray with a rubber friendly lubricant. We used ACF50 to help the replacement o-rings bed into their grooves properly ...

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The replacement o-rings in place ...

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Next we clean the solid lifters and apply some GP greas to the stem and also to the rear of the lifter face ...

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This is done to ensure that the lifter has some initial lubrication when the engine is returned to service and also to ensure that the lifters sit in position in the crankcase when it comes to rejoining the crankcases. We can take this opportunity to grease the face of the solid lifters as well as the back or we can apply grease to the cams on the camshaft - either option works ...

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Here is a solid lifter half way inserted ...

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And here are some images of the lifters in their correct position fully seated ...

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Next up is ensuring the main bearings are fully seated having previously inspected and measured them for excessive wear. Do the same for the thrust bearings ensuring correct orientation - there is a right way and a wrong way to fit them. If you are re-using previously used bearing then you should have made a note of which bearings went where to take advantage of previous component bedding in ...

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In this close up you will see that the main bearings have been lightly oiled and the thrust bearings are held in place with the light adhesion of some GP grease. It is not good practice to apply grease to the main bearings for fear of blocking vital oil flow ...

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Here you can see we have two crankcase halves, cylinder barrels, pistons, thru bolts, 12 point nuts organised and barrel base o-rings all in position. It is really important to make sure that the 12 point nuts turn freely on the thru bolts otherwise the torque'ing up process will be more arduous than it needs to be. These thru bolts and nuts were previously torque'd up using (at a guess - judging by the colour) some Loctite 620 when they are supposed to be assembled "dry". The thru bolt and nuts must be clear of all traces of any compound and thoroughly cleaned before beginning ...

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Here we have the cleaned up crankshaft bolted to the engine table with a home made degree wheel in place at it's base. The degree wheel will be used to set camshaft timing / postioning ...

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Next we apply Loctite 620 to the mating faces of the crankcases having thoroughly degreased them first. Using a roller is not essential but it definately helps to achieve a thin and even coating of gasket compound. Excess compound has the potential to be squeezed out when the crankcase halves are torque'd up and the excess can fall of into the sump and potentially block the lubrication system. Be very careful to avoid getting compound anywhere it shouldn't be e.g. main bearings, thrust bearings etc ...

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Here we see the crankcase halves loosely pushed together ...

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There are no thru bolts in place yet! Before we go any further now is a good time to lubricate the camshaft cam lobes with GP grease for initial running whilst oil pressure gets up ...

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