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Comp 918's and .571 lift?

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Old 07-27-2004, 09:08 PM
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Default Comp 918's and .571 lift?

I am getting a new cam for my turbo ls1 and the lift will be somewhat like .571/.558

My question is, will this be ok for comp 918's even though they are rated to .600 lift? Or should I spend the additonal $150 and get patriot duals?
Old 07-27-2004, 09:10 PM
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you will be fine on the 918's but **** if u ever wanna go big might as well go with the duals.
Old 07-27-2004, 09:13 PM
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Ive been running 918s with .578" lift for 5k miles. No problems so far.

However, since youre runnin a turbo you might need some stiffer springs. The turbo boost exerts some pressure on the back of the intake valves, trying to push them open. This might be too much for the 918s.
Old 07-28-2004, 10:31 AM
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I ran my 918' s with a .581 lift for 15,000 miles and no problems. The 918's are good for 35,000 miles according to different sources. When they were first on the market the max lift for the 918's were .620. I think comp reccommended .600 and below to raise sales on their dual's.
Old 07-28-2004, 10:43 AM
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918s can handle .625" lift. Take a look at the 1.085 coil bind height. Installed height is 1.800"...you can do the math. Now the only question is, can the springs control the vavles at .625"...depends on the setup.
Old 07-28-2004, 10:44 AM
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918's are great springs, you'lll be fine.

Just make sure to keep up on your maint. I wouldn't run ANY single spring on a high performance application for more than 15K miles. Not saying it won't last that long, but with a single spring you damn sure do not want to find out...
Old 07-28-2004, 11:23 AM
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Originally Posted by Damian
918's are great springs, you'lll be fine.

Just make sure to keep up on your maint. I wouldn't run ANY single spring on a high performance application for more than 15K miles. Not saying it won't last that long, but with a single spring you damn sure do not want to find out...

Yes thats my main concern. I just shelled out a bunch of cash for a new motor and don't want to be dropping valves.
Old 07-28-2004, 11:59 AM
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Originally Posted by Unusual T/A
Yes thats my main concern. I just shelled out a bunch of cash for a new motor and don't want to be dropping valves.
There have been more dual springs broken than 918s. There have been no reported cases of 918 blue stripes breaking. My buddy broke a 941 back in the day, and it didnt do anything to his motor, but make it run funny. No PTV contact was made...Yes he was lucky.




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