Cubby engine failure

[robkkbke]

Cubby flywheel problem

Cubby -DVR experienced an engine stop luckily while still on the ground. Upon investigation we found major bearing failure probably caused by a loose flywheel.
The flywheel is normally a separate item bolted onto the crankshaft. Usually dowels confirm the exact position and bolts ensure the attachment. If things come loose havoc is created.
Some Jabiru engines suffered this and their SB 012 deals herewith. On a J3300 engine here at FAWC we have to replace the washers under the 5/16 screws for a better service.
In attached pic’s the VW engine of -DVR shows the many loose dowels. Once the dowels are loose the timing is out, vibrations are present and all is loaded more than normal ending in seizure somewhere.
We inspected another Cubby. The flywheel attachment on Cubby –DTR is just 5 bolts and a dowel which is not clearly visible. The bolts are marked with paint so any looseness can be quickly seen.
VW engine owners should check this. It is not too difficult to see.

[Jean Crous]

Just to clarify some points:

1) the five bolt crank is from the 2.1"waterboxer" engines used in the Kombi 2.1. and has a stroke of 76.4mm.

2)The crank with the central bolt and the dowels is an aftermarket VW type 1 cranck of 82mm stroke.

3) If the central bolt is torqued to the correct value then there should not be any problems, we normally put a dab of thread-lock on the bolt before installing.

4) Unless the ignition system has been changed from the original Cubby set-up , the loose flywheel cannot have any influence on the timing, as the distributor runs off a distributor drive on the front of crancshaft , as per normal for these engines. I am no expert on these engines , and the older Cubby`s with the VW conversions were before my time with the business .

Thanks Rob for drawing the attention to this problem.
Jean.