Cracks in the combustion chamber

jman · Post by **jman** » Tue Jun 27, 2006 8:27 pm

Here is another little problem. I have pictures of the machining of the "D", can anybody tell me how far the machining can go above and below the spark plug hole? Also how deep does the machining need to be?.

graham · Post by **graham** » Sat Jul 01, 2006 9:02 am

Place a bare rotor in the housing and turn it in the direction of rotation. Watch for the exhaust port being uncovered. Once the exhaust port is visible (open by a few mm). Draw a pencil line just above the plug hole across the housing using the apex seal slot for support. Don't grind the 'D' any higher than this -or you will release exhaust gases the wrong way, under the gap left by the newly ground 'D'. The shape isn't important within reason, the idea is to include any cracks radiating from the spark plug hole before they get any worse. Obviously, the 'D' shape must finish before the exhaust port closesDifficult to show on a photo,I'll upload one to the gallery if it looks good enough.Depth of grind - throught the Nikasil to aluminium.Just a thought; I've read that Felix Wankel invented Nikasil. Can anyone confirm it?Graham

jman · Post by **jman** » Mon Jul 03, 2006 8:47 pm

Thanks Graham for the info, listen out for the next tragic instalment of the rebuild!

graham · Post by **graham** » Mon Jul 03, 2006 8:58 pm

Glad to help.Sorry I was so slow, I'm a bit preoccupied for another few weeks then I'll be more availableGraham

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