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Comet timing
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<blockquote data-quote="nkt267" data-source="post: 5982" data-attributes="member: 245"><p>I did a full mapping of the mark 3 cams in my nephews Comet today as I felt that it lacked a bit of lustre in the performance department.</p><p>I found that the lift timing and static timing,inlet relative to exhaust,did not match the stated figures.</p><p>I found that the inlet opening was near enough correct and the exhaust closing was right,but inlet closing was 10deg late and the exhaust closing correct.</p><p>The lift at TDC was inlet opening 0.80in(late) exhaust closing 0.56(early)</p><p> BDC was inlet closing 0.210(late) exhaust opening 0.225(ok-ish)</p><p></p><p>I know that it is better to have the inlet opening early rather than the exhaust close late,but any ideas as to the best compromise. </p><p>My gut feeling is to leave it alone as I am comparing it to my Comet that has standard compression ratio with mark2 cams,which also do not match the stated figures but I compromised on the timing marks and the performance is fine.<img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite8" alt=":D" title="Big Grin :D" loading="lazy" data-shortname=":D" /></p></blockquote><p></p>
[QUOTE="nkt267, post: 5982, member: 245"] I did a full mapping of the mark 3 cams in my nephews Comet today as I felt that it lacked a bit of lustre in the performance department. I found that the lift timing and static timing,inlet relative to exhaust,did not match the stated figures. I found that the inlet opening was near enough correct and the exhaust closing was right,but inlet closing was 10deg late and the exhaust closing correct. The lift at TDC was inlet opening 0.80in(late) exhaust closing 0.56(early) BDC was inlet closing 0.210(late) exhaust opening 0.225(ok-ish) I know that it is better to have the inlet opening early rather than the exhaust close late,but any ideas as to the best compromise. My gut feeling is to leave it alone as I am comparing it to my Comet that has standard compression ratio with mark2 cams,which also do not match the stated figures but I compromised on the timing marks and the performance is fine.:D [/QUOTE]
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Comet timing
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