1500 SOHC valve clearance problem

Discussion in '1.0 Mirror' started by User1, Feb 19, 2009.

Thread Status:
Not open for further replies.
  1. User1

    User1 RETIRED Admin, pm OFF Staff Member

    Location:
    Seattle
    <TABLE cellSpacing=1 cellPadding=6 width="100%" border=0><TBODY><TR><TD colSpan=2><TABLE width="100%" border=0><TBODY><TR><TD style="PADDING-TOP: 4px" vAlign=top colSpan=2>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]1500 SOHC valve clearance problem<!-- google_ad_section_end -->

    [/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial]November 18 2000 at 6:58 PM[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript> <!-- var n54_em; n54_em = ""; n54_em = n54_em + "m";n54_em = n54_em + "f";n54_em = n54_em + "r";n54_em = n54_em + "e";n54_em = n54_em + "e";n54_em = n54_em + "m";n54_em = n54_em + "a";n54_em = n54_em + "n";n54_em = n54_em + "i";n54_em = n54_em + "s";n54_em = n54_em + "@";n54_em = n54_em + "h";n54_em = n54_em + "o";n54_em = n54_em + "t";n54_em = n54_em + "m";n54_em = n54_em + "a";n54_em = n54_em + "i";n54_em = n54_em + "l";n54_em = n54_em + ".";n54_em = n54_em + "c";n54_em = n54_em + "o";n54_em = n54_em + "m"; document.write("Mark Freeman"); // --> </SCRIPT>Mark Freeman <NOSCRIPT></NOSCRIPT> [/FONT]</TD></TR><TR><TD vAlign=bottom colSpan=3><HR></TD></TR><TR><TD colSpan=3>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<!-- google_ad_section_start -->(also posted on Mirafiori forum [​IMG]

    So, I recently bought a 79 X1/9 with dual DCNFs and autocross cam. In order to pass an emissions test i'm putting a 32 DATRA on it and putting the stock cam back in. One problem - contrary to my expectations of having fat shims (because performance cams are often regrinds with smaller base circle) - it seems I need really thin shims:

    All the intakes are 3.00 shims, the exhausts are around 4.00. But I have no measurable clearance on any valves! Smallest i've seen are around 2.50 and even these might not be small enough. I even tried a different cam housing in case this one had been decked but no change. All of my spare shims are 4.00 and above too.

    My thoughts are: try and find small shims, try to double/triple/up on the cam box gasket (not sure if this will help much), or try and file down the top of the valves (tough to do right and I really don't want to pull the head).

    It's been 10+years since I rebuilt a Fiat engine - I have this feeling I'm forgetting something...Any thoughts gratefully received - anyone else had this problem?

    Mark<!-- google_ad_section_end -->

    [/FONT]</TD></TR></TBODY></TABLE><TABLE cellPadding=4 width="100%" border=0><TBODY><TR><TD vAlign=top noWrap align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial] [/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial][​IMG] [/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Author[/FONT]</TD><TD>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Reply[/FONT]</TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Warren[/FONT]
    [FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 15px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<!-- google_ad_section_start -->Is it possible that your valves arn't stock?<NT><!-- google_ad_section_end -->

    [/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]November 18 2000, 7:47 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 15px">
    [FONT=Trebuchet MS, Verdana, Tahoma, Arial]<!-- google_ad_section_start --><NT><!-- google_ad_section_end -->

    [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=4 width="100%" border=0><TBODY><TR><TD vAlign=top align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial] [/FONT]</TD><TD vAlign=top noWrap align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial][​IMG] [/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]warren[/FONT]
    [FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 15px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<!-- google_ad_section_start -->I for got... you can get more shims from the older Volvos, they use the same ones.<NT><!-- google_ad_section_end -->

    [/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]November 18 2000, 8:06 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 15px">
    [FONT=Trebuchet MS, Verdana, Tahoma, Arial]<!-- google_ad_section_start --><NT><!-- google_ad_section_end -->

    [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=4 width="100%" border=0><TBODY><TR><TD vAlign=top align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial] [/FONT]</TD><TD vAlign=top noWrap align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial][​IMG] [/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript> <!-- var n54_em; n54_em = ""; n54_em = n54_em + "s";n54_em = n54_em + "e";n54_em = n54_em + "r";n54_em = n54_em + "v";n54_em = n54_em + "i";n54_em = n54_em + "c";n54_em = n54_em + "e";n54_em = n54_em + "@";n54_em = n54_em + "i";n54_em = n54_em + "m";n54_em = n54_em + "p";n54_em = n54_em + "o";n54_em = n54_em + "r";n54_em = n54_em + "t";n54_em = n54_em + "a";n54_em = n54_em + "u";n54_em = n54_em + "t";n54_em = n54_em + "o";n54_em = n54_em + "t";n54_em = n54_em + "e";n54_em = n54_em + "c";n54_em = n54_em + "h";n54_em = n54_em + ".";n54_em = n54_em + "c";n54_em = n54_em + "o";n54_em = n54_em + "m"; document.write("steve ambrose"); // --> </SCRIPT>steve ambrose <NOSCRIPT></NOSCRIPT>[/FONT]
    [FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 15px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<!-- google_ad_section_start -->Be Careful.....<!-- google_ad_section_end -->

    [/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]November 19 2000, 8:08 AM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 15px">
    [FONT=Trebuchet MS, Verdana, Tahoma, Arial]<!-- google_ad_section_start -->Hi Mark, not sure what's going on with the head, but be very careful with using very thin shims. If you go too thin,the cam lobe will hit the tappet, not the shim! One thing to check about your head; are you sure that the tappet presses on the valve stem, not the valve spring cap? With the cam box off, the tappet should rock easily on the top of the valve. If it sits flat (on the top of the cap), then no amount of shim changing will affect the clearance.
    Worse case, why don't you put it back the way it was, and use a stock head,cam, and carb for your e-test? It's not that hard to swap heads, and that way you'll have your autocross setup ready to go...
    Steve
    <!-- google_ad_section_end -->

    [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=4 width="100%" border=0><TBODY><TR><TD vAlign=top align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial] [/FONT]</TD><TD vAlign=top noWrap align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial][​IMG] [/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Ulix[/FONT]
    [FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 15px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<!-- google_ad_section_start -->Which cam?<!-- google_ad_section_end -->

    [/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]November 19 2000, 6:47 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 15px">
    [FONT=Trebuchet MS, Verdana, Tahoma, Arial]<!-- google_ad_section_start -->Mark,

    do you need thin shims with the performance cam or the stock cam?

    I have a PBS regrind cam in my head with lengthened valves. If I were to try to put a stock cam in, I would run into exactly what you describe.

    Ulix<!-- google_ad_section_end -->

    [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=4 width="100%" border=0><TBODY><TR><TD vAlign=top align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial] [/FONT]</TD><TD vAlign=top noWrap align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial][​IMG] [/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Mark[/FONT]
    [FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 30px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<!-- google_ad_section_start -->yes, the stock cam is the problem<!-- google_ad_section_end -->

    [/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]November 19 2000, 7:07 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 30px">
    [FONT=Trebuchet MS, Verdana, Tahoma, Arial]<!-- google_ad_section_start -->I can't remember what brand the other cam is. <!-- google_ad_section_end -->

    [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=4 width="100%" border=0><TBODY><TR><TD vAlign=top align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial] [/FONT]</TD><TD vAlign=top noWrap align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial][​IMG] [/FONT]</TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE>
     
Thread Status:
Not open for further replies.

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice