Detonation is caused by having too volatile fuel. Your friend would
need to go to a higher octane fuel (higher octane fuel resists
detonation.) If he is still having issues and is already using a
premium fuel, then something else is the issue.

On Sep 15, 2009, at 11:04 PM, Ian Allan wrote:

> I have a friend who purchased a van with a Go Westy 2.4 engine. The
> engine has suffered from detonation issues among other things. Any
> ideas as to practical machining processes to REDUCE the compression
> ratio?
>
> Ian