Wednesday, January 14, 2009

Conversion to single oil bath primary/crank areas

Hi, not a lot done over the Christmas holidays due to a bearing machining disaster. New bearing on way when I can at last start the full rebuild. In the meantime I have shown here a few pics of a conversion I have done on the drive side crankcase, to share oil source with engine and also to improve engine breathing.

The two ports drilled (below drive side bearing) are such that their lower level is in line with the top side of the screw boss which can just be seen under the lower stator fixing in bottom pic. This is so that the two holes act as a weir keeping the oil level consistent with the previous method which had its level drain in the top of the outer casing boss in the same position. (Dont forget to fill with oil on assembly though).

I am counting on the oil/air mist being blown about in the lower crankcase to feed this area with fresh oil in running. I have, to assist this, replicated the oil drain from the ledge on the inner of the casing on the drive side. On the timing side this ledge/oil feed supplys the inner timing cam cam bush so there is an oil source there. This hopefully will drip feed into the primary case area just up over the main drive sprocket. I will post how I get on later, but all ports have been threaded so that the operation is reversible without splitting the crankcases.
Edit: To finish primary crankcase breathing
Rather than port any air fluctuation out through the chain oiler (which I want to block permanently) I have vented the oil filler/clutch adjuster cap. Pics can be seen above. There is a raised ridge within that can be drilled to hold a baffle. Two further holes vent the air. I used a 10c coin as the baffle as it has a serrated edge and fits perfectly.
It also has 2008 Eire on the coin and a harp.= when and where the rebuild was started.

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