Droptoplt1ta

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

Unaffliated Racing

iTrader: (15)

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

SNLPerformance

iTrader: (15)

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.

Jason 98 TA

iTrader: (4)

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

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

Jason 98 TA

iTrader: (4)

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

TurboBuick6

iTrader: (2)

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

Droptoplt1ta

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!

Droptoplt1ta

An exhaust valve broke? Its less lift on my cam