What 7,000rpm does to a valve spring
#1
Team Owner
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Location: Boston, Dallas, Detroit, SoCal, back to Boston MA
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What 7,000rpm does to a valve spring
It's on a strobe light so you can see what's happening
yes, 7 tenths inch lift cam!
Nascar engine from 7 years ago. 7000rpm with a .700 cam lift.
Last edited by BrianCunningham; 04-21-2007 at 12:10 AM.
#5
Le Mans Master
Thanks for the video, BrianCunningham.
Watch how much the tip of the valve stem moves around under the
end of the roller rocker after the valve 'seats'.
Three-component springs are not uncommon. Sometimes there is a
flat damper between and inner & outer. Or three round or ovoid wire
springs.
An example is COMP CAMS #26028-1: "engineered to deliver
performance in 1.000” lift engines while turning 9,000 to 10,000 RPM."
Seat Load: 346 @ 2.200
Open Load: 1074 @ 1.200
Coil Bind: 1.150
Rate(lbs./in.): 728
.
Watch how much the tip of the valve stem moves around under the
end of the roller rocker after the valve 'seats'.
Three-component springs are not uncommon. Sometimes there is a
flat damper between and inner & outer. Or three round or ovoid wire
springs.
An example is COMP CAMS #26028-1: "engineered to deliver
performance in 1.000” lift engines while turning 9,000 to 10,000 RPM."
Seat Load: 346 @ 2.200
Open Load: 1074 @ 1.200
Coil Bind: 1.150
Rate(lbs./in.): 728
.
#6
Burning Brakes
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Wow - the secondary harmonics are wild. I wonder if this is the case throughout a significant rpm range, or whether this occurs only at a very specific rpm. Every system has a natural harmonic, so if it is the latter, it probably would be much less worrisome than if it happened, say, from 6500 to 7500 rpm.
#7
Melting Slicks
Wow - the secondary harmonics are wild. I wonder if this is the case throughout a significant rpm range, or whether this occurs only at a very specific rpm. Every system has a natural harmonic, so if it is the latter, it probably would be much less worrisome than if it happened, say, from 6500 to 7500 rpm.
The spring has mass, and it will try to contine to move after the valve closes, but this looks like it is behaving pretty well, when you consider how quickly the system is daming out.
Last edited by Solofast; 04-21-2007 at 11:42 PM.
#8
Le Mans Master
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St. Jude Donor '03 & '05
Are there anymore videos of this for current set ups? Beehives and .600 lifts would be intersting to see.
Well I found one, about half way down on the left, Beehive video, right click and save.
http://www.compcams.com/information/...ry/Default.asp
Well I found one, about half way down on the left, Beehive video, right click and save.
http://www.compcams.com/information/...ry/Default.asp
Last edited by steve40th; 06-04-2007 at 01:09 PM.