Cam to big for springs?

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Sep 14, 2011 | 09:19 PM

Droptoplt1ta

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Launching!

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From: Clinton Twp, MI

Cam to big for springs?

I just had a spring break on my setup.

I have L92 heads with the PAC 1518 springs. I bought these heads used which owner stated they had about 1k miles on them (they were clean and in good shape). L76 engine.

I installed them and a cam of the size of 231/236 .641"/615" 112lsa, and engine ran ok for almost 1 hour of total run time, and then I got a noise and found a broken spring.

Is that cam to big for these springs. Any idea for cause of failure?

Thanks

Sep 15, 2011 | 11:33 AM

Unaffliated Racing

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Considering that it coil binds at .660", I'd say yes. Single spring, big valve, too much lift.

Sep 15, 2011 | 11:34 AM

SNLPerformance

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From: Ft. Worth, TX

Yeah, that super aggressive LSK lobe combined with a big/heavy L92 intake valve definitely needs a dual spring, hopefully damage wasn't too bad.

Sep 15, 2011 | 12:03 PM

Jason 98 TA

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From: Texas!

You need something like the PRC Double .650" spring kit.

http://www.texas-speed.com/p-474-pre...pring-kit.aspx

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Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
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Sep 15, 2011 | 12:04 PM

Jason 98 TA

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From: Texas!

we have some stock valves in case you hurt one, give us a call if you need a spare!

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Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com

Sep 15, 2011 | 03:10 PM

TurboBuick6

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If you want to keep PAC's on there many vendors on here including Texas Speed carries our new small diameter duals.

Sep 16, 2011 | 06:26 PM

Droptoplt1ta

Thread Starter

Launching!

Joined: Nov 2005

Posts: 276

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From: Clinton Twp, MI

I see the PAC 1518 springs are rated to .650, so I figured I was ok when I bought these heads..... Also, it was an exhaust spring that broke - I see the intake on this cam has more lift than the exhaust...

Thanks Jason. I will likely be calling you guys soon to take you up on that!