Might be making progress?

[phil_long]

I've been doing a LOT of reading, but I have yet to find any material as to how the valve springs work and why it seems to be one of the first mods.  I've read a couple threads after searching and searching, and seen someone say if your car accelerates hard, then seems to hit a wall, then it could potentially be valve springs.  Im not interested in throwing parts at the car, but I seem have an issue with my car pulling at higher RPM's.  Thanks for any input fellas

[earlbrown]

Valve springs do two things. They hold the valve closed so it can make a seal and they keep the lifter in contact with the cam. (Imagine the damage a hammer will do pushing down on a nail as opposed to a hammer bouncing off the nail and slamming down on it).

If the springs don't have enough poundage to keep the valvetrain stable then all hell breaks loose and power pretty much ceases to be made at that point.  If you hop in my time machine, go back to '87 and get one of these cars brand new, the springs are too weak. Years of age and/or use just make the problem worse.

[phil_long]

Valve springs do two things. They hold the valve closed so it can make a seal and they keep the lifter in contact with the cam. (Imagine the damage a hammer will do pushing down on a nail as opposed to a hammer bouncing off the nail and slamming down on it).

If the springs don't have enough poundage to keep the valvetrain stable then all hell breaks loose and power pretty much ceases to be made at that point.  If you hop in my time machine, go back to '87 and get one of these cars brand new, the springs are too weak. Years of age and/or use just make the problem worse.

Thats a great analogy.  Hopefully im not reading TOO much into the analogy, but, would you say that the healthy valve spring would represent the hammer NOT bouncing off the nail, and actually supply the pressure upon the nail until lifting off the throttle?  Sorry if i sound dumb

[phil_long]

And, the reason i mention this is because I ORIGINALLY thought it was the tranny, but after a certain RPM, my foot could be through the floor, and the car doesn't pull again until after shifting.  My trans shifts completely fine and firm, and the car pulls pretty good when im NOTat WOT, but its when it holds in gear longer at WOT that the car falls flat on its face. 

[phil_long]

And, you can actually feel the springs being too weak throughout a WOT pull?  Thanks again

[Steve Wood]

The cam profile ultimately limits the rpm IF the valve springs are in good condition.

If the valve springs are tired (any car that has the factory original springs was probably tired at 50,000 miles) then the lifters will not have enuf pressure exerted on them to stay in contact with the lobes before the engine reaches the end of its power band.  Stock cam with stock turbo was usually done around 4800 because it ran out of air flow.  With a bigger turbo, it would usually start dropping off around 5200 rpm but the engine might rev to 5400 or so but with less power.  Engine combo will have a lot of affect on this.

Putting stiffer springs on will not do much for power because the cam was not designed for high rpm output being its a turbo but they will allow all the performance originally in the car plus a little more if they are a bit stiffer..

I have seen many a Regal that dropped on its face at 4000 rpm because the springs did not have enuf pressure to close the valves under boost.

Replacing the springs with new ones makes all the difference in the world.  No need to go too radical because the cam lobes were made for relatively low rpm-

[phil_long]

Ok, thanks for the info. Trying to understand the operation to know what im looking for. As mentioned before, the car is SUPER strong at low RPM's.  Its not like it slowly fades away as RPM increases, it literally feels like it stops pulling and waits to shift and then i get hit with a load of power once again.  Its consistent throughout all gears.  Guess this might also explain why my 3rd gear pull feels like shit.  Under part throttle to maybe half throttle, the pull is consistently strong, but of course this isn't WOT at the 17 lbs of boost i need to get a stiffy!!

[phil_long]

But, i have still been researching and read a few people complaining about wiping out their stock cam(which is where i dont want to be).  Seen some folks going with the comp 980's, but i dont want to throw parts at my car anymore.

[Steve Wood]

so, do you want to have it run properly, or, are you satisfied with it as it is?  You confuse me.

If you put a too stiff spring on an old cam, you might have a problem, but putting something equivalent to the 980s which are only slightly stiffer than the factory springs is not much risk.  You can always put some Joe Gibbs break in oil, or one of the additives and run it for a few miles for added insurance...I generally do.

[earlbrown]

Keep in mind that putting "stiffer" springs that are in spec isn't really a bad thing. Yes, they have more poundage but the extra stiffness brings them up to spec most of the time.

Also, adding stiff springs to an old cam and lifters is actually much preferable to stiff springs on new units. New parts are are made of crappy cam blanks with crappy lifters that don't have tougher stellite feet. When cams and lifters bed-in they work harden as they marry together. After running the stock parts for years and many many miles they're set up for stiff springs much better than new parts.

What RPM is you car shifting at?  And can you tell what RPM the car falls on it's face before the shift?

[phil_long]

Not my intent to confuse.  I want the car to run properly.  Im only researching to get an idea of what it is I'm up against.  Thats all!

[phil_long]

And Earl, Im going to check into that today.  I hadnt had any intent to pay attention to RPM's until after researching last night.  I mainly watched KR and O2 count.  I revved it in park and the RPM's got as high as 3733, but due to how slow the SM monitoring is, i didn't trust it.

[phil_long]

Might have to buy a tach?

[Steve Wood]

why do you need a tach?  You have a scanmaster. It reads plenty fast for what you are doing.

Earl summed it up well in his last post

[phil_long]

ok