<HTML><FONT FACE=arial,helvetica><HTML><FONT SIZE=2 PTSIZE=10 FAMILY="SANSSERIF" FACE="Arial" LANG="0">Bill, at the settings you describe, the engine should run fine. The next place to look is the possibility of overcompression. The head and/or liner may be machined a few thousandths off. Try adding the head shim and run it a little richer as Ron and Dave suggest.<BR>
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I have seen a bunch of Webras run and none seems to have a problem with blowing plugs. But these are machined components and subject to natural variation so it is possible yours is the lucky engine. <BR>
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The Mintor 170 on the other hand is a real plug hog; especially the early vintage engines. The later vintage has head shims added for smoother more reliable function and it helps in that area.<BR>
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hope that helps a little and good luck<BR>
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MattK<BR>
<BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Subj:<B>Re: Glow Plugs </B><BR>
Date:7/8/2004 10:27:46 PM Eastern Daylight Time<BR>
From:<A HREF="mailto:phelps15@comcast.net">phelps15@comcast.net</A><BR>
Reply-to:<A HREF="mailto:discussion@nsrca.org">discussion@nsrca.org</A><BR>
To:<A HREF="mailto:discussion@nsrca.org">discussion@nsrca.org</A><BR>
<I>Sent from the Internet </I><BR>
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Matt:</FONT><FONT COLOR="#000000" BACK="#ffffff" style="BACKGROUND-COLOR: #ffffff" SIZE=3 PTSIZE=12 FAMILY="SANSSERIF" FACE="Arial" LANG="0"><BR>
</FONT><FONT COLOR="#000000" BACK="#ffffff" style="BACKGROUND-COLOR: #ffffff" SIZE=2 PTSIZE=10 FAMILY="SANSSERIF" FACE="Arial" LANG="0">I have a Greve pipe, and it's 29 1/2 to rear baffle, and 32 1/2 to end of pipe.....by all estimates, very conservative...... I use 15% nitro/16% oil Powermaster fuel, and am turning a 17x12 7900 rpm. </FONT><FONT COLOR="#000000" BACK="#ffffff" style="BACKGROUND-COLOR: #ffffff" SIZE=3 PTSIZE=12 FAMILY="SANSSERIF" FACE="Arial" LANG="0"><BR>
</FONT><FONT COLOR="#000000" BACK="#ffffff" style="BACKGROUND-COLOR: #ffffff" SIZE=2 PTSIZE=10 FAMILY="SANSSERIF" FACE="Arial" LANG="0">Bill</FONT><FONT COLOR="#000000" BACK="#ffffff" style="BACKGROUND-COLOR: #ffffff" SIZE=3 PTSIZE=12 FAMILY="SANSSERIF" FACE="Arial" LANG="0"><BR>
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<BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">----- Original Message ----- <BR>
<B>From:</B> <A HREF="mailto:Rcmaster199@aol.com">Rcmaster199@aol.com</A> <BR>
<B>To:</B> <A HREF="mailto:discussion@nsrca.org">discussion@nsrca.org</A> <BR>
<B>Sent:</B> Thursday, July 08, 2004 5:25 PM<BR>
<B>Subject:</B> Re: Glow Plugs<BR>
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Bill, is your pipe set short? The pipe I use (Hatori) has the first deflector plate located at 23.75" from the glow plug, straight line or around 24.5" along the centerline of the header. Are you running a large enough prop to keep rpm at around 78-8000 or so? <BR>
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I typically will run one type F plug per 150 runs in the 145, using a 20% nitro and 19% oil blend. My fuel blend is a 50:50 mix of 10%cool power and 30% heli cool power. The large head of the Webra (large heat sink) just about requires the hot F type plug to run right. I've had limited success running other plugs in the engine.<BR>
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hope that helps you <BR>
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MattK</BLOCKQUOTE><BR>
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