ls6 springs or comp bee hive

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Originally Posted by mean05

...plus they were a lot of problems with the comp springs breaking

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There's no need to perpetuate this issue. The problem with broken 918 springs was resolved last year. There was a stress-relieving step omitted from several batches in 2006 from Comp's supplier at the time. The affected batches were recalled and Comp replaced the 918's with the 928's, which have better performance specs.

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Originally Posted by Madd Maxx

There's no need to perpetuate this issue. The problem with broken 918 springs was resolved last year. There was a stress-relieving step omitted from several batches in 2006 from Comp's supplier at the time. The affected batches were recalled and Comp replaced the 918's with the 928's, which have better performance specs.

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just stating facts...didnt know the recalled all of them...PRC springs are the best bang for the buck anyways

Fair enough. I just wanted to make sure that forum members realize that, yes, there was a problem with some of the 918 springs, but that Comp handled it quickly and to the satisfaction of their customers. They are a quality company with outstanding customer service.

While I agree the PRC springs are a quality product with a very good price, I would consider dual springs to be a little overkill for the OP's modest cam choice. Those specs appear to be the Vinci Ultra Torque grind (made by Crane). That cam's power curve is pretty much done by 6000 RPM, so it doesn't need the extra valvetrain stability that dual springs would provide. So the price he would pay for being able to rev higher with a cam that won't, or for having a little added protection if one spring were to break, is a constant HP loss. Higher spring pressure increases pumping losses - it takes HP to compress the springs.

Plus, the ovate, beehive springs solve a problem that round, constant-diameter springs have - resonance at various RPM points. That resonance also costs HP and can be seen on some dyno plots.

Sorry for the long diatribe, but selecting performance parts is not like increasing HP - a little more is good, a lot more is way better, and too much is just right. There is a lot of engineering behind valve spring design and selecting the right spring is important for optimizing output.

Quote:

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Originally Posted by Madd Maxx

Fair enough. I just wanted to make sure that forum members realize that, yes, there was a problem with some of the 918 springs, but that Comp handled it quickly and to the satisfaction of their customers. They are a quality company with outstanding customer service.

While I agree the PRC springs are a quality product with a very good price, I would consider dual springs to be a little overkill for the OP's modest cam choice. Those specs appear to be the Vinci Ultra Torque grind (made by Crane). That cam's power curve is pretty much done by 6000 RPM, so it doesn't need the extra valvetrain stability that dual springs would provide. So the price he would pay for being able to rev higher with a cam that won't, or for having a little added protection if one spring were to break, is a constant HP loss. Higher spring pressure increases pumping losses - it takes HP to compress the springs.

Plus, the ovate, beehive springs solve a problem that round, constant-diameter springs have - resonance at various RPM points. That resonance also costs HP and can be seen on some dyno plots.

Sorry for the long diatribe, but selecting performance parts is not like increasing HP - a little more is good, a lot more is way better, and too much is just right. There is a lot of engineering behind valve spring design and selecting the right spring is important for optimizing output.

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:badteef: dimz iz beg werdz :badteef:

Quote:

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Originally Posted by Madd Maxx

Fair enough. I just wanted to make sure that forum members realize that, yes, there was a problem with some of the 918 springs, but that Comp handled it quickly and to the satisfaction of their customers. They are a quality company with outstanding customer service.

While I agree the PRC springs are a quality product with a very good price, I would consider dual springs to be a little overkill for the OP's modest cam choice. Those specs appear to be the Vinci Ultra Torque grind (made by Crane). That cam's power curve is pretty much done by 6000 RPM, so it doesn't need the extra valvetrain stability that dual springs would provide. So the price he would pay for being able to rev higher with a cam that won't, or for having a little added protection if one spring were to break, is a constant HP loss. Higher spring pressure increases pumping losses - it takes HP to compress the springs.

Plus, the ovate, beehive springs solve a problem that round, constant-diameter springs have - resonance at various RPM points. That resonance also costs HP and can be seen on some dyno plots.

Sorry for the long diatribe, but selecting performance parts is not like increasing HP - a little more is good, a lot more is way better, and too much is just right. There is a lot of engineering behind valve spring design and selecting the right spring is important for optimizing output.

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well...nice job on the cam id it is a vinci 080 grind...is anyone running that cam by chance?

i would love to hear an idle clip? :)

http://thumbs.vidiac.com/b7ea55f6-d7...5394a45414.jpgClick here to see Video
http://thumbs.vidiac.com/b979b04c-e0...0f00317c87.jpgClick here to see Video

Here are a few from performancetrucks.net. I'm not sure about the specs on the cam in the first vid and the one in the second vid sounds like it has a lot smaller lsa.

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Originally Posted by banker099

well...nice job on the cam id it is a vinci 080 grind...is anyone running that cam by chance?

i would love to hear an idle clip? :)

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Here's a clip from Vinci's 056 cam. It uses the same lobe profile as the 080, but has a little more duration, and hence, a little more overlap. The 080 cam would sound very similar and maybe be just a tiny bit smoother.

http://www.vincihiperformance.com/vi...s/DSCF0026.wmv

Hmm....that's magazine/manufacturer speak.

That cam designer's shop is where? And magazines are written where?