Mkos1980

iTrader: (4)

Cam is a Trick Flow 228/230 585/585 with 243 heads on a LQ4 shortblock.. I was thinking the PAC single springs but the limit is only 600. Is there usually a "margin" there should be from max lift on the cam to max lift for the spring? I've run the 918's with good luck on my Vortec headed marine engine but never on an LS engine. I've heard of the springs breaking but also ehard that problem was taken care of. Thoughts?

batboy

iTrader: (6)

In addtion to their .600 lift spring, PAC also makes a single beehive spring rated for .650 lift if you don't want to go with duals.

http://www.texas-speed.com/shop/item...=1065&catid=48

adkunlimited

i found this link for you. i hope it helps in your selection. there is more to it then just the springs rated lift. check it out. http://www.kennedysdynotune.com/Valv...ing%20Tech.htm

vettenuts

iTrader: (4)

Rated lift doesn't mean anything, you need to know the required seat value and compute all your clearances and open force of the spring. If the installed seat value is too low, you need to shim to increase the seat force.

adkunlimited

who said it does?

The_Rizzle

iTrader: (4)

We just had a thread like this. The springs rated lift already has a safety factor. As long as you're using the springs in the recommended application, you should fine, esp. with PAC products.

1218's coil bind at 1.140, installed at 1.8 gives you .660 lift max. Minus your .060 safety factor, and you've got the .600 rated lift. Pressures of 130/318 as a beehive are plenty unless you're revving to the moon with 6.0 valves. If you want more pressure, shim it to get to max rated lift. At that point you have to KNOW you cam's lift is correct, along with the installed height the same for all the valves.

New 918's are rated to .625, and coil bind at 1.110.

JPH

iTrader: (2)

Either PAC beehive valve springs will get the job done for you with no issues.

vettenuts

iTrader: (4)

The OP is basing things on rated lift.

SweetS10V8

iTrader: (4)

Comp totally redesigned the 918s after they had a few batches with issues. The new ones are silver in color, the old one have the blue stripe. I run them on basically every engine Ive built including my own which is .607/.621 lift. I even had to shim them to get them where they needed to be.

Springs should be based off of measured coil bind height.

garygnu

call tsp great price fast service.

Jon@Texas-Speed

iTrader: (18)

Either PAC spring will get the job done. You can also run a Comp 918 if you like. We have run a TON of all three springs without issue. Give us a call and we can get you fixed up. We stock several different springs for whatever you need.

Jon