I have come to the centre main bearing strap and I noticed the longer replacement bolt had eaten into the metal of the strap. You can see the raised area under the bolt head. The original bolt on the right is recessed in that area, which allows full contact with the cap.
This short engine was originally from Avonbar and I am surprised that it wasn't fitted with flanged bolts or washers to spread the load.
I will be fitting hardened steel washers.
I notice that the kit from mini spares doesn't seem to have washers with it.
I found this article which is worth a read as it questions the need for this mod
http://www.calverst.com/articles/Engine ... issues.htm
Centre main strap mod
Centre main strap mod
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