Knock yourself out dude, no one stopping you. lol

Just using math i learned in grade school .600 max lift minus .551 lift with a TR220 leaves .049. And the fact that I manually spun the engine and verified that nothing was binding. Plus its a cam package hundreds have put in I knew I would be fine.

I am finished and await your technically correct, but unpractical retort.

 

the valve height remains the same, however if the replacement spring is a different height than what was there before that is the problem, the intent of this thread was to find out how many folks know if their setup is done right or just swap and flop... guess lots more people have faith in the springs they are replacing with than I do... especailly after years of seeing folks have trouble with the 918s over and over again.

 

BigMike, its nice that you think that math is relevant here... I've seen cams with .525" lift break .600" max lift springs... that is just one small portion of what is going on here... also it is very cool that your highly trained eye can detect binding in a spring by turning the motor over by hand, even though you must realize that turning it by hand, and turning it 6000 rpm would present a slightly different situation... right?

 

why do I think what exactly?

the distance between the cylinder head or any shims/locators and the part of the retainer where the spring goes when the valve is closed is the installed height.

I have a feeling that your mind is on the right track, but your fingers aren't transmitting it properly. You are simply using the term "INSTALLED HEIGHT" incorrectly.

 

that is correct unless you also change the retainers/locks/locators/shims.

 

Why would you assume that the springs binding is the only reason they break?


I keep things simple. If it breaks I replace it, if it isn't broke, I find something better to put it. lol

 

If you are using the same sets and retainers as before, installed height does not change. Installed height only changes when you switch out seats, retainers or valves. All the 918's were breakingf because of spring material not installed height problems.
Checking installed height is more for getting max seat pressure for better high RPM performance. I did this on my 98 SS when i installed my T Rex cam. I measured then shimmed the springs .045" to get maximum seat pressure, since i was revving this cam to the moon.
You don't need to worry about about measuring for coil bind with 99% of the springs people run on LSx motors, unless you use some custom heads, valves or spring kit.
All that being said I've installed about 180 cams and have only checked installed height in a hand full of swaps. They were all pretty much race only applications. I just swapped out all the other 175 sets of valve springs including the ones i did last week on my Escalade.

 

i am no mechanic so take it easy on me, if i choose to change my cam is the springs the only thing i need to change?

 

People will tell you to change pushrods, but i don't think it's that big a deal for what most people want to do.

 

Checked it on my camaro when I did them. I will check them on my truck when I swap my LS1 with LS2 GTO cam and 241's with a little work done to them in my truck.