are 918 springs enough??
Thread Starter
Instructor
Joined: Dec 2002
Posts: 237
Likes: 0
From: Geneva Nebraska
are 918 springs enough??
I've just ordered a CompCams custom grind. Here are the specs on the cam: 228/230 .588/592 Lift on a 113 LSA. Now I know the 918's are rated up to .600 lift, but does a guy need to give himself a little cushion when ordering springs. For instance, will these 918s be sufficient, or should I upgrade to 921's? Any help would be appreciated. Thanks.
Shaun
Shaun
Race Director
Joined: Nov 2003
Posts: 16,067
Likes: 4,150
From: Bergen county NJ
I'd suggest buying the best comp 921 dual spring kit.
the 918's might break and then your in deep..
There are other less expensive dual springs that are good choices too..
I wouldn't personally run single valve springs on an uprated cam in my car, nor would I recommend them to a friend.
Take it for what its worth.
Good luck
the 918's might break and then your in deep..
There are other less expensive dual springs that are good choices too..
I wouldn't personally run single valve springs on an uprated cam in my car, nor would I recommend them to a friend.
Take it for what its worth.
Good luck
Melting Slicks
Joined: Aug 1999
Posts: 3,452
Likes: 3
From: Spring, TX
918's are rated to .600 lift. at .592 you are within 98.6% of max lift. That is cutting it too close. I would use a good double spring. There are sets that don't require machining the heads just replace the spring seats and valve seals.
I run the 918's on my car but my lift is .575 which is 95% of max lift.
I run the 918's on my car but my lift is .575 which is 95% of max lift.
Last edited by gonbad; Aug 19, 2006 at 05:50 PM.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
They changed the lift on the 918's when the 921's came out so the two springs wouldn't compete, they used to be rated for higher lift. Spring hasn't changed. I personally like the beehive design better than a straight spring, better harmonic characteristics, lower mass, lighter retainer, etc. The PSI springs are rated to 0.625 and are also sold as Isky Tool Room springs, they are also a beehive design.
