Reason for stagerring lift #`s on cams??
11-29-2002, 01:18 PM
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Re: Reason for stagerring lift #`s on cams?? If you want to increase the flow from the intake or the exhaust, but you dont want to raise the rev range or the valve opening and closing points.
J.
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11-30-2002, 12:33 AM
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Reason for stagerring lift #`s on cams?? Just wondering what the reason is for some cams having different lift numbers on exhaust versus intake. Why not just have the same lift on both int and exh?? Just wondering what the advantages are ...
thanx
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thanx
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11-30-2002, 12:54 AM
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Re: Reason for stagerring lift #`s on cams?? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Superman:
<strong>Just wondering what the reason is for some cams having different lift numbers on exhaust versus intake. Why not just have the same lift on both int and exh?? Just wondering what the advantages are ...
thanx
<img border="0" alt="[chug]" title="" src="graemlins/gr_chug.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">If the intake doesnt flow the same as the exhaust, why should the lift numbers be the same?
<strong>Just wondering what the reason is for some cams having different lift numbers on exhaust versus intake. Why not just have the same lift on both int and exh?? Just wondering what the advantages are ...
thanx
<img border="0" alt="[chug]" title="" src="graemlins/gr_chug.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">If the intake doesnt flow the same as the exhaust, why should the lift numbers be the same?
11-30-2002, 01:45 PM
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Re: Reason for stagerring lift #`s on cams?? Here is my reasoning about this. I know nothing about camshaft design but it doesn't suprise me that exhaust and intake lobes sometimes differ. I have wondered why lift and duration are usually identical given that exhaust gasses are much hotter than the intake charge. Exhaust pressure and velocity must be higher than intake so the conditions for optimal flow differ. So far as I know, the exhaust valve is always smaller than the intake valve.
-Gary
-Gary
11-30-2002, 01:52 PM
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Re: Reason for stagerring lift #`s on cams?? Another thought: It is simpler and therefore less expensive to make a camshaft with identical profiles for intake and exhaust.
-Gary
<small>[ November 30, 2002, 07:12 PM: Message edited by: Gary Z ]</small>
-Gary
<small>[ November 30, 2002, 07:12 PM: Message edited by: Gary Z ]</small>
12-01-2002, 12:17 AM
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Re: Reason for stagerring lift #`s on cams?? Also with split patters or reverse splits the durations are different. The lobe profile determines lift. So naturally the lift will be different on a 220/224 cam for intake and exhaust. Also mixing different lobe profiles can accomplish different goals example G5 224 XE-R intake and 230ish XE exhaust.
Say you wanted to go with a 224 cam as that's as big as you can go and still pass emissions. You don't want to beat on the springs anymore than you have too and you want the valves as quite as you can get them.
A 224 XE-R intake and a 224 XE exhaust might work pretty well. 224/224 581/568 lift ...just an example.
Say you wanted to go with a 224 cam as that's as big as you can go and still pass emissions. You don't want to beat on the springs anymore than you have too and you want the valves as quite as you can get them.
A 224 XE-R intake and a 224 XE exhaust might work pretty well. 224/224 581/568 lift ...just an example.