the cam is the 600/600 lift. is it possible to use the 918 springs or aim i going to have to go dual?

 

I'd go dual....don't skimp.

 

i understand but will they work without binding?

 

i run 918s with my cam thats .595/.598 i think they work fine......

 

They may work without binding for a while but you won't get many miles out of them because they will have to compress so much. That takes alot of life out of a spring. Maybe more people will put some input on it

 

i am searching online as we speak and what about shimming it?

 

You can use them, but I would suggest checking them every 10,000 to 15,000 miles to make sure they do not wear out. If you go dual there is more comfort because they will not wear out as fast.

 

I have the same question. I'm looking to run a cam with .595" lift and would really prefer to run the 918's for both cost and ease of installation. I was also under the impression that single springs tended to last longer than duals. The .600" that Comp specifies includes a margin for safety against coil bind so is there really any verifiable negative effect to running the spring up to its maximum recommended value?

 

that sums it up

 

yep, until a spring breaks and a valve says hi there to the piston.

 

But the question is why would a spring break when its being operated within the manufacturers recommended range? If Comp says its safe what do you guys know to contradict them? I'm not asking this to be confrontational just trying to make a good decision and looking for a little more informed input. Thanks

Nate

 

It is about stress. If you are going to operate the spring on the edgenof its performance limits be prepared to check them regularly. If you want to put them in and not worry about checking use duals. It how depends on how much maintenance you want to do, and the margin of safety you prefer.

 

From what I have read, the 918's were originally rated to 0.625 lift. Note that the lift is also based on an installed height and as you decrease the installed height you also decrease the lift capability of the spring. Bottom line, make sure you buy a valve spring micrometer and understand your installation parameters.

 

I had the same dilemma with my cam, its .610/.601, I just decided to spring for the duals and picked up a set of the new Patriot Gold Xtreme from their sale this month. I tend to be more on the careful side when it comes to stuff on this car though, that and I used to work in insurance. I heard the same thing about the 918s being underrated, I just didn't want to take the chance with valve springs.

 

john at futral motorsports said with proper install and titanium retainers that 918's should be fine so...