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VALVETRAIN QUESTIONS

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Old Dec 31, 2001 | 01:58 PM
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Default Re: VALVETRAIN QUESTIONS

Yep, as GeorgeC pointed out it all depends on where you are starting from. With *any* aftermarket cam you need better springs.


Now what if it's a stock cam+ nitrous. Many people have proven this works. Some have also had problems. Nitrous *is* harder on the valvetrain. Rotational velocity (rpm) isn't the only factor here - that may stay the same or even be lowered, but the rotation acceleration (rate at which rpm changes), jerk (third derivitive), etc. are all greately increased. You are moving through the rpm band faster, giving the spring a greater energy input to control. Then there are also other factors like increased cylinder pressure, etc. which may effect the springs slightly.

Do you absolutely have to with a stock cam? No. Is it a good idea? Yep. But then kill 2 birds with one stone and upgrade to some decent springs *and* stick a cam in there <img src="gr_stretch.gif" border="0">


Chris

[ December 31, 2001: Message edited by: ChrisB ]</p>
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Old Dec 31, 2001 | 02:13 PM
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Default Re: VALVETRAIN QUESTIONS

Bill-

I think I know what you gots a cookin'. <img src="gr_stretch.gif" border="0">

I would do a set of LS6 or 915 springs, maybe more. IMO it's something you SHOULD do if you plan to spin the motor up to 6400 a lot.

I am still running my stock rockers which have 40K on them, and have seen 7100 rpms a few times. <img src="gr_stretch.gif" border="0">
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Old Dec 31, 2001 | 02:55 PM
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Default Re: VALVETRAIN QUESTIONS

Thanks everyone for responding so soon.

I am using my stock cam.

I will more than likely go with the 915's to be on the safe side since I road race occasionally. I was just worried about the stock rockers. I heard a couple of people breaking the stock rockers. As far as durability goes, how are the stock retainers and pushrods?

Springs should be a piece of cake on a C5 I hope <img src="gr_grin.gif" border="0">

Thanks,
Bill F.
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Old Dec 31, 2001 | 03:25 PM
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Default Re: VALVETRAIN QUESTIONS

M6 car right Bill?

My opinion is do the pushrods if you are doing springs..you're in there already and it would be cake..

stock pushrods are these motors can be junk..not hard to trash them when spinning the motor high alot. Cromoly pushrods aren't much money for the insurance they give.

let me know if you need help doing the work anytime soon.

Sean
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Old Dec 31, 2001 | 03:51 PM
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Default Re: VALVETRAIN QUESTIONS

Bottom line is one really bad misshift and you can end up floating valves and bending pushrods, maybe even valves.

Stock valvesprings really suck. As far as the LS1 goes, they are one of the weakest links.

Might also want to look into stock 02 LS6 springs. Not sure if the retainers are different.

Should be cake on your car. <img src="gr_stretch.gif" border="0">
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Old Jan 1, 2002 | 12:12 AM
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Default VALVETRAIN QUESTIONS

Say I am planning on a power adder but keeping the same cam and do not plan an reving past 6400 rpms, would I still need to upgrade my valvetrain (springs, rockers and pushrods) for the added power or is a need for the better valvetrain a function of the lift of the cam and the rpms?

I am looking for around 450 at the rear.

Thanks,

Bill F.
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Old Jan 1, 2002 | 12:19 AM
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Default Re: VALVETRAIN QUESTIONS

No you don't need to do anything. I have been shooting 100HP for a year or two with no problems. However I am now installing a new cam. The stock parts will do fine for the time.
Opps; I should ask how much power you adding? If you go to a 150 shot smoe say you need a bigger fuel pump some don't. I would side on safty.

[ December 31, 2001: Message edited by: 2000 Camaro SS ]</p>
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Old Jan 1, 2002 | 12:40 AM
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Default Re: VALVETRAIN QUESTIONS

You don't need to, but it wouldn't hurt in the long run
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Old Jan 1, 2002 | 12:52 AM
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Default Re: VALVETRAIN QUESTIONS

What do you mean by the "same cam?" Do you have an aftermarket cam in the car now, or are you referring to keeping the stock cam?

I would upgrade the valvesprings with any aftermarket cam. The new Comp 915 and 918 springs make this a little easier since you can reuse the stock retainers.

If you're referring to a power-adder with the stock cam, some Comp 915 springs wouldn't be a bad idea, although not necessarily a "must do."
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