I need to replace my springs due to various problems. They need to have proper support for the lift and duration of a LT4 cam (NOT THE HOT CAM). I would like them to also have room for growth if possible. But this is a bit of a time and money issue So I need to at least be in spec for currently and just look at aluminum AFR heads in the future. I also want to know what else can be replaced while the heads stay on the car. Ie seals guides etc. I've never done this so I will get getting with fellow NTTGA members to handle this task since alot of you guys are all over the US. I don't want to have to pull the heads for the time and excess cost that is involved in this.

 

I would think Comp 986's would fill the bill, but someone else might have a different idea.

 

Keep in mind what ever springs would need to fit without enlarging the L98 head. That way I'm not spending even more money that I already don't have.

 

The 981's are 1.25" OD, have .550" from installed height to coil bind.

 

Those springs have a dampener. I'm kinda hoping for no dampener. Granted I don't know what purpose the dampener serves, but that is the problem I'm having now. A friend of mine (The president of NTTGA Vern) made the 60 mile drive from Plano to south FTW to help me set the lash. Well I got the covers off and needless to say there were pieces of valve seals, some round shaped broken white plastic pieces, and about 4-5 various pieces of the retainer spring just laying around inside the head on top in the corners. I cleaned all that crap out drained the oil to see if it was shiny (pieces of metal) and to see if there were any chunks in the lower end. Needless to say we never set the lash with thoughts that it would do me no good.

So I'm trying to repair this problem without removing the heads. As I don't have the money to change springs as it is. I'm hoping I can sell this set of LT1 cast iron heads I have and this other set of L98 heads to pay for any parts I will need to redo this. The springs on the car now were supposidly replaced when they put the cam in. Obviously they weren't the right lift or were incorrectly installed to cause this crap. I know that they are aftermarket though because they do have the dampener and they have a small inner spring also.

 

Ok meaning? I don't know the internal engine tech talk. I've always just messed with outer bolt on repairs and such. I drove a 2.8 marrow up untill nov of last year So I haven't done really any performance stuff as this car was already started off with exhaust cam suspension transmission and brakes. So I'm not too keen on the measurements.

 

You shouldnt be concerning yourself if there's a damper or not, thats not a problem with a valvetrain, improper choice of parts with regard to dimensions is.

What ratio are the rockers? Stock?

If I were you, I'd find someone with a micrometer at the least and find out what your installed height is or you might just be back in there before you can say the word go. If someone has been in there changing parts, they might have used retainers limiting your clearance AND choice of springs, and then you are really stuck.

 

All the guy said who replaced them is that the LT4 cam was installed and a set of springs so I'm guessing the retainers and rockers are stock. The rocker arms are stock.

 

This is what the springs look like that are on it. The outer spring with the dampner and then the inner spring[URL="http://www.sdpc2000.com/catalog/1321/products/111133/1465-Dual-Harmonic-Frequency-Optimized-Valve-Springs.htm"[/URL]
What would cause the dampener to break and also the green valve seals to break up in chunks? Springs not being long enough? and getting over extended?

 

Springs being too long/tall and being over compressed.

I suspect your retainers are also different, because unless I havent seen something really unusual, those springs on your car now are ~1.4" OD and that wont work with the factory retainers. Likely whats on there now was for those springs with a step for the inner spring. If I had to guess, you probably dont have adequate retainer-valve seal clearance nor adequate spring coil clearance and thats probably why you have chunks of seals and metal floating around. The 981's are probably your best bet with some appropriate retainers and not having any idea whats on the car now and what may have been done to the heads if anything.

 

I bought what was called LT4 springs from scoggindickies performance . SD1007 . @ 1.8"installed height it was 120 lbs. @ 1.2" it was 350 lbs. Stock 1.25 diameter. Also good for 570 lift.

 

That link was just for reference to what is on the car. I have no idea if that is the spring that is on there. It just looks like that and has the small inner spring
What I'm looking for is a adequet set of springs for a lt4 NON hot cam with a small ammount of room to grow if need be and also links to all parts that can be replaced while the head is still on the car. I have no intentions of spending all the excess for new headbolts and gaskets if the need isn't there. I have heard the springs and seals can be replace while still on the car the sparkplugs need to be removed and the chamber filled with air.

 

Ditto on this. We had the pockets cut on our L98 heads and had these springs setup for us. Love them.

 

I'm trying to avoid cutting the pockets. i don't want to remove the heads. I don't have the cash for all the extra crap or I would just pull them and send the whole head in and have them reworked. Heck I have a set on the balcony I could do that too if I really wanted to. Send um in then when they come back pull mine off put those on I'm done. BUT I would like to stray away from pulling the heads. That means much more work then I have time to deal with right now. Not to mention if I do pull them I will be putting my supercomps on and spending more money having the y pipe fabricated. So I would wish to avoid cutting pockets and will like to stay with stock diameter springs I just need to know what will work as a stock diameter and still allow for adequete lift and duration of the cam. with a little room to spare.

 

I'm running the same heads and cam. I'm using Comp 983's. I got the whole kit with the retainers and locks. Works great so far