What effect do ramp rates have on how an engine runs?
12-06-2001, 02:11 PM
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Re: What effect do ramp rates have on how an engine runs? Valvetrain stability on pushrod OHV engines with stock weight valvetrain components usually becomes an issue at revs over 6,400 rpm. However this is in a short duration drag racing scenario, long duration endurance racing like circle track or road racing, valvetrain stability is much more important. In those forms of racing you probably wouldn't want to turn stock weight valvetrain components at much over 6,000 rpm for hours on end.
12-06-2001, 02:27 PM
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12-06-2001, 11:07 PM
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Re: What effect do ramp rates have on how an engine runs? 2quick....you answered your own query, I never said the 941 was the proper spring for an aggressive lobe....but it was and still is the spring of choice for some. I have used it in several applications when that was all that was available and had only a single spring (as in one spring, not one set) fail after repeated 6600-7K runs at the track and on the street.
You can't blame the lobe for a poorly constructed spring...the wire used in the 941 has come into question and rightly so....I can still promise an aggressive lobe and 100K durability with the right components and the proper installation...no exceptions. If you really want to insure stability...go to a rev kit, but realistically an LS1 will not see a lobe worthy of a rev kit.
Just as an FYI....the ASA guys use Z06 springs and stock valvetrain....makes you wonder huh?!?!?
[ December 06, 2001: Message edited by: HouseofSpeed ]</p>
You can't blame the lobe for a poorly constructed spring...the wire used in the 941 has come into question and rightly so....I can still promise an aggressive lobe and 100K durability with the right components and the proper installation...no exceptions. If you really want to insure stability...go to a rev kit, but realistically an LS1 will not see a lobe worthy of a rev kit.
Just as an FYI....the ASA guys use Z06 springs and stock valvetrain....makes you wonder huh?!?!?
[ December 06, 2001: Message edited by: HouseofSpeed ]</p>
12-07-2001, 11:24 AM
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Re: What effect do ramp rates have on how an engine runs? [quote]Originally posted by HouseofSpeed:
<strong>
Just as an FYI....the ASA guys use Z06 springs and stock valvetrain....makes you wonder huh?!?!?
</strong><hr></blockquote>
Yes they do, and their fuel cut-off is set at 6,800 rpm to boot. I would imagine though that the ASA, being a factory GM cam, has less aggressive ramps than some of the other popular aftermarket grinds. The factory engineers are fairly conservative like myself. Other things to remember is that these engines are completely rebuilt every year and they run a quasi, semi-dry sump type oiling system which is much better than stock. This system insures adequate oiling to the springs and other areas.
BTW: Don't see anyone breaking springs with a GM HOT cam do you? Moderately aggressive ramps is why.
[ December 07, 2001: Message edited by: 2quick4u ]</p>
<strong>
Just as an FYI....the ASA guys use Z06 springs and stock valvetrain....makes you wonder huh?!?!?
</strong><hr></blockquote>
Yes they do, and their fuel cut-off is set at 6,800 rpm to boot. I would imagine though that the ASA, being a factory GM cam, has less aggressive ramps than some of the other popular aftermarket grinds. The factory engineers are fairly conservative like myself. Other things to remember is that these engines are completely rebuilt every year and they run a quasi, semi-dry sump type oiling system which is much better than stock. This system insures adequate oiling to the springs and other areas.
BTW: Don't see anyone breaking springs with a GM HOT cam do you? Moderately aggressive ramps is why.
[ December 07, 2001: Message edited by: 2quick4u ]</p>
