is it possible to get more lift by using after market valve springs. i have stock vortec heads and put in new valve springs. had a machine shop install / seals. shop said my cam lift will be good up to .490 . just not sure if valve springs can make this differance. im understanding a vortec head will accept only up to a .480 lift. crane #99848-16 springs were used

 

no, ur lift is a product of your cam and your rockers. the springs will not affect this. did you also put in bigger rockers?

 

no just the stock 1.5 rockers. my cam is .465 / .488 just dont want to ruin a motor with more cam than my motor / heads will accept

 

the only way you would ruin them is if the lift is too high for piston/valve clearance and you smack ur piston with a valve. i really doubt ur going to be anywhere near that with a .4xx lift cam. u never mentioned what you drive however.

 

If the machine shop measured the retainer/valve seal clearance you should be good to go. The rule of thumb so to speak is measure the actual clearance then take off .060" for a saftey factor. I think the machine shop may have cut down the the place where the valve seal goes for clearance they might have also decreased the diameter because stock you can only fit a single spring on it. There are beehive spring kits that come with special retainers that allow for additional lift also. Springs do need to be sized for the application but in general will not have a bearing on the lift. Most vortecs in stock form will be in the danger zone at .470 lift.

 

What kind of special retainers allow for more lift???
Sly

 

they arent special, they are just shaped differently which allows the spring to be slightly more expanded than normally. however this lowers seat pressure, i wouldnt go this route.

 

http://www.carcraft.com/techarticles...ade/index.html

http://www.youtube.com/watch?v=NskusJdk5Qs

The major downside I see is cost, I know people who run the beehive spring with no complaints so far. I am cheap and shaved down the stock retainer got a set of stiffer springs and tossed out the spring damper, the beehive spring is a better setup.

Spector I dont really understand your comment... when you install a valve spring you need to measure the installed height and coil bind the problem with the vortec isnt the spring lift but the valve seal height and the diameter they only allow for a single spring that is where the advantage of the beehive spring comes in.

 

in that article they talk about machining the stem guide, which is the area that the spring seat sits on. this would do the same thing as lifting the retainer a little, just on the other end.

 

How do you lift the retainer?