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All depends on the system. Low rpm stuff, anything will work really as long as its not in bind. High rpm, aggressive valve motion .100+, Think Im at .120 or so

In discussing this topic you need to also discuss how your figuring max lift. Measured with checking springs or measured with actual springs. You go from a lightened rocker and small pushrod to a rigid rocker and thick pushrod you can change your valve lift a bunch depending on your spring. Dynamically the system will also change those numbers.

The nose of the lobe on most successful high rpm/power cams, look untouched. IMO as always
 

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Just did one last weekend, basic 7500 rpm bracket deal. Went for 0.080" with Manley springs. We will see how she likes it.
 

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So when you guys check coil bind do you just use math from the spring manufacturer specs or do you actually measure it with feeler gauges or something
 

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So when you guys check coil bind do you just use math from the spring manufacturer specs or do you actually measure it with feeler gauges or something
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.
 

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Discussion Starter #17
So when you guys check coil bind do you just use math from the spring manufacturer specs or do you actually measure it with feeler gauges or something

I used math after checking the actual coil bind.
Using feeler gauges would be pretty tough as the number is distributed across the coils.
 

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Discussion Starter #18
The comments by goneracin are pretty interesting.
I didn't know deflection (without considering loft) goes away while running.

I went for .060 on my solid roller engine.
It seems nice and close without being risky...

I started this thread because I want to set up a hydraulic roller which seems more difficult since I don't feel comfortable just shimming away.
I can get to .080 which sounds fine when looking at all the replies.
 

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Thanks. So on a SS 2.19 valve @ 0.796 lift and 8600 rpm with stiff pushrods and steel shaft rockers what would you recommend ?
A Titanium valve! Lol
 

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The comments by goneracin are pretty interesting.
I didn't know deflection (without considering loft) goes away while running.
I could be wrong, but I believe he is saying you cannot measure deflection without a Spintron because it is only there while it is running. It doesn't show itself while checking statically with indicators because there is no dynamic force being applied like a running engine.
 
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