valve spring question
 

here is my valve spring specs

•Outside Diameter- 1.268"
•Inside Diameter- .880"
•130 Lbs @ 1.790"
•330 Lbs @ .500" Lift
•345 Lbs @ .550" Lift
•360 Lbs @ .595" Lift
•Average Coil Bind- 1.140"

max lift is .595

I'm lookin at a lunati voodoo cam with 1.6rr and the max lift is cutting it real close on the exhaust side to the max lift. it would be .587" lift

Will i need to get new springs or do you guys think it will be ok?

Re: valve spring question
 

Get new springs. Typically .030" of clearance between coil bind and max lift are recommended. .007" is much too close. You won't want to have to do it again. The cam card will recommend the proper valve spring.

Re: valve spring question
 

ok haha thanks Joe

Re: valve spring question
 

Hold up... 1.79" install height with 1.14" advertised coil bind is 0.650" lift to coil bind. I like .050" to coil bind clearance (and that seems commonly recommended minimum .050-.060, some like more) so that gives .600" lift capacity on those springs.

You should be fine at .587", however depending on the cam specs and rpm ranges, you may want more pressure over the nose and on the seat anyway.

Re: valve spring question
 

I am either reading something wrong or my head is full of cheese but, assuming they are installed at 1.78, with a 1.14 bind, wouldn't you have .640 lift to bind, with a clearance of .053 for the cam/rocker specified? Edit: ruling out head full of cheese.

Re: valve spring question
 

Those have plenty of room. Whatever springs they are, the company listed the max on the safe side. Just be damn sure you install them at the proper height. Buy one of those $20 spring height checking tools. I can't tell you how many times I've read threads were people slap a set of springs on a stock head (beehives typically) and then a month later they are crying because they broke one, and they never took the time to measure. If you put those springs on your head and they are too tall, they sell shim packs to tighten them up. If you install them and they are too tight they sell special locks that raise the retainer up slightly. Keep in mind if you have to use the special locks you won't be able to run self-aligning roller rockers as the valve tip will be almost flush with the retainer.

Re: valve spring question
 

And if thats the case, then you may have retainer to rocker arm clearance issues. I know I did on my new setup. What I had to do was run a lock with recesses in them for lash caps. Ran a .080" lash cap to raise the stem for the roller rockers inorder to gain clearance from retainer to arm of rocker. My springs are 1.37" diameter tho

Re: valve spring question
 

LT1 VALVE SPRING KIT Includes: SPRINGS, RETAINERS, LOCKS & CUPS. - Alex's Parts Sales

thats the valve spring kit i have. its currently in the car with the current cam. it says that they are only good for .595 but who knows?

edit: rockers are SA ... will be switchin to NSA

Re: valve spring question
 

You are good to go. Can cam up to .595" lift as recommended. .587 is < .595 so you are good. Their numbers appear to be a tad conservative if average coil bind is 1.14 and install height is 1.79. But some spring people use .060 or more inches to coil bind, some use .050". They are using .055" which is between common specs. You should measure your install height because if its at 1.77 or so, then you now have only .570-.580" lift assuming .050-.060" clearance from coil bind. You can go tight but you risk bottoming out the spring coils as they vibrate at higher rpms, if float ever occurs.

Old AFR 8002 springs were advertised at .550" lift max but my friend has run .576" on them since they have a large coil bind clearance. I dont advise this at all as he was likely under .030" clearance now but it ran ok...just that the springs werent enough for the cam to begin with and it floated anyway.

Re: valve spring question
 

alright thanks for the help guys!