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Idiot Savant
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we were forced years ago to buy an expensive computerized spring dyno due to one manufacturers inconsistency.
so we actually run every spring we use on all the engines we build through it and get their actual solid height.
some springs are held to a pretty tight tolerance. some not as much, but typically they bind shorter than the box says, so they are not going to go solid if you use the box specs. you can always make soft jaws for a vise and bind them in the vise and measure.

our typical distance from bind on bracket stuff is .090 ish from measured max lift with checkers. Without spin data, you are guessing at it if you factor in deflection, because most if not all of the deflection comes back dynamically when its running. And thats not factoring in loft. Which is why we use actual measured lift with checkers. Its amazing how much most rockers are over advertised ratio.
Most guys that make rockers don't understand ratios. Most guys that use them don't either.
 

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My only reason not already going to Ti, besides the cost, is that I have two sets of manley and didnt want the maintenance of Ti and don't love lash caps. I have never ran Ti and just going by others. The hollow stems may be a good option. These ss are 139g on the 2.19 intake and 108g for the 1.71 ex
Ferrea hollow stem on the intake
 

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not really what i meant. ill try to explain what i mean
if you put the real parts on the engine (springs rockers pushrods etc) and measure net lift at the valve turning it over, you will have less lift than what math would tell you due to parts deflection.
Some, if not all of this deflection goes away during operation as the parts will "pole vault" or unwind to a certain degree and straighten out.. Granted what ive seen on the spintron was prostock, so reasonably aggressive....lol, but the prostock actually had more lift than the math said it should due to loft. So for us, i always measure the lift with light checkers to get the actual ratio of the rockers, and get the lift assuming the polevaulting gets me back to that lift. Then we set the springs up based on this theoretical unwinding. Since i do not have a spintron, i can only assume this as we dont spin every combination.
make sense or did i do a shitty job of explaining myself....lol.
it makes sense in my head anyway
Good explanation. Then add in cylinder pressure, cam twist and all the other dynamics of a running engine and check it again. :)
 
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