<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:13px"><div id="yui_3_16_0_ym19_1_1461030396303_3488"><span id="yui_3_16_0_ym19_1_1461030396303_3487">Hi Jim,</span></div><div><span></span><br></div><div id="yui_3_16_0_ym19_1_1461030396303_3499" dir="ltr"><span id="yui_3_16_0_ym19_1_1461030396303_3498">103-104 at the lobe is where you want to be. The 270 would be at the valve.</span></div><div id="yui_3_16_0_ym19_1_1461030396303_3497" dir="ltr"><span></span><br></div><div id="yui_3_16_0_ym19_1_1461030396303_3496" dir="ltr"><span>Hope this helps?</span></div><div id="yui_3_16_0_ym19_1_1461030396303_3495" dir="ltr"><span></span><br></div><div id="yui_3_16_0_ym19_1_1461030396303_3516" dir="ltr"><span>Rick</span></div> <div class="qtdSeparateBR"><br><br></div><div class="yahoo_quoted" style="display: block;"> <div style="font-family: HelveticaNeue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 13px;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div dir="ltr"><font face="Arial" size="2"> On Monday, April 18, 2016 6:47 PM, "toodamnfunky@comcast.net" <toodamnfunky@comcast.net> wrote:<br></font></div> <br><br> <div class="y_msg_container"><div id="yiv4681683778"><div><div style="color: rgb(0, 0, 0); font-family: Arial; font-size: 12pt;"><div>FoT<br></div>
<div>I'm building a motor for a club member and am having some difficulty with cam timing specs. It's an APT</div>
<div>cam and the spec sheet they provided is not only nonsensical but it has some of the data crossed out and </div>
<div>some of the numbers hand written in. No real usable data on timing it for it's best performance. At best it's really </div>
<div>more of a fast road cam. I didn't spec the cam or buy it. It has 108 degree lobe centers, .280 lobe lift and a </div>
<div>duration of 270 degrees at .020 lift. The data sheet says Time to ATDC 103 - 104 degrees and it's supposed to have</div>
<div>.071 lift at TDC. This cam won't do both.</div>
<div>When I time it to 104 degrees ATDC at full lift I get 9 degrees BTDC at .071, which also translates to 20 degrees BTDC at .050 lift</div>
<div>which to me sounds more reasonable. I've contacted APT twice now and the first answer was a lot of jibberish and they </div>
<div>haven't answered the second inquiry yet regarding the math that will not work.</div>
<div>What I don't want to do is inadvertently RETARD the cam. I'm used to working with .050 for valve opening but APT doesn't consider </div>
<div>.050 an open valve. </div>
<div>Any advice would be more than welcome.</div>
<div>jim g</div></div></div></div><br>_______________________________________________<br><a href="mailto:fot@autox.team.net" ymailto="mailto:fot@autox.team.net">fot@autox.team.net</a><br><br><a href="http://www.fot-racing.com/" target="_blank">http://www.fot-racing.com/</a><br><br>Donate: <a href="http://www.team.net/donate.html" target="_blank">http://www.team.net/donate.html</a><br>Archive: <a href="http://www.team.net/archive" target="_blank">http://www.team.net/archive</a><br>Forums: <a href="http://www.team.net/forums" target="_blank">http://www.team.net/forums</a><br>Unsubscribe/Manage: <a href="http://autox.team.net/mailman/options/fot/rick.parent@att.net" target="_blank">http://autox.team.net/mailman/options/fot/rick.parent@att.net</a><br><br><br><br><br></div> </div> </div> </div></div></body></html>