ramp rate/valve spring ?'s
02-09-2007, 02:51 PM
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ramp rate/valve spring ?'s Does the closing rate of a cam effect valve springs(or any of the valvetrain) as much as opening ramp rate? IE will a cam with a mildly aggressive opening ramp that snaps shut quickly(aggressive closing ramp) effect valve springs like a cam with an aggressive opening ramp would?
More specifically, does closing rate effect valve float as much, more less than opening rate? What about lifter bounce?
More specifically, does closing rate effect valve float as much, more less than opening rate? What about lifter bounce?
Last edited by eLTwerker; 02-09-2007 at 03:20 PM.
02-09-2007, 04:22 PM
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Originally Posted by eLTwerker
Does the closing rate of a cam effect valve springs(or any of the valvetrain) as much as opening ramp rate? IE will a cam with a mildly aggressive opening ramp that snaps shut quickly(aggressive closing ramp) effect valve springs like a cam with an aggressive opening ramp would?
More specifically, does closing rate effect valve float as much, more less than opening rate? What about lifter bounce?
More specifically, does closing rate effect valve float as much, more less than opening rate? What about lifter bounce?
02-09-2007, 10:19 PM
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This is just a hypothetical question really. Here's an example, though. All things being equal(valvetrain, heads, etc..) will cam A with a XE lobed opening and aggressive closing rate have the same effect on valve float, wear, etcc.. as cam B with an XE-R lobed opening and a more mild closing rate. Assume same mild ramp rate on opening of cam A as closing of cam B just to furthur keep things equal.
02-09-2007, 11:28 PM
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Originally Posted by eLTwerker
This is just a hypothetical question really. Here's an example, though. All things being equal(valvetrain, heads, etc..) will cam A with a XE lobed opening and aggressive closing rate have the same effect on valve float, wear, etcc.. as cam B with an XE-R lobed opening and a more mild closing rate. Assume same mild ramp rate on opening of cam A as closing of cam B just to furthur keep things equal.
2. The ramp rate both opening and closign will affect springs.
02-10-2007, 10:22 AM
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Originally Posted by brad8266
1. XE-R's have more lift for a given duration than an XE, hence more aggressive for given durations.
2. The ramp rate both opening and closign will affect springs.
2. The ramp rate both opening and closign will affect springs.
02-10-2007, 11:58 AM
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Originally Posted by brad8266
1. XE-R's have more lift for a given duration than an XE, hence more aggressive for given durations.
2. The ramp rate both opening and closign will affect springs.
2. The ramp rate both opening and closign will affect springs.
What do you see?
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02-10-2007, 02:18 PM
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Yeah well I thought Comp defined XE-R as .006-.050= 49 or lower and XE as 53 or higher. I thought XE-R lobes are more aggressive in general, maybe not at every single point(except .050-which defines the lobe).
