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In a message dated 1/7/14 14 44 1, lashdeep@yahoo.com writes:<BR>
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<BLOCKQUOTE CITE STYLE="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px" TYPE="CITE"></FONT><FONT COLOR="#000000" FACE="Geneva" FAMILY="SANSSERIF" SIZE="2">On long uphill (high load) sections of road, under moderate throttle openings and when the supercharger goes into positive boost, the engine starts to ping. This will happen only when in overdrive and with revs below 2000rpm.<BR>
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>>>I'm far from an expert but it sounds like a classic case of excessive compression. I suspect that the blower was bolted onto a standard engine; ideally the compression ratio would have been lowered when the engine was built.<BR>
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You suggested different heads, which is perhaps a viable solution, but another choice might be to change pistons to lower the CR?<BR>
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What about water injection?<BR>
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Mike</FONT><FONT COLOR="#000000" FACE="Geneva" FAMILY="SANSSERIF" SIZE="2"></FONT></HTML>