"White Knight"

Alright i want to take a poll on who thinks i should change valve springs.

My car has 130,000miles on it. I have the mods in the sig, and run a 13.5 at 98mph. My car dies when it gets up in the power band--everything i can think of has been changed, so who here thinks changing springs will help? And help how much?

92rslt1

I dont see why you would change valve springs at 130000 miles. almost time for a rebuild and a cam

turbo_Z

I wouldnt waste money on a tired motor.

Sunsceamer

Before you do that do a compression test. Do one test cold and one test with car at operating temp.

I would change them after that anyway with just hot cam springs since there cheap.

96capricemgr

Those that say the LT1 is worn out at that milage don't know jack about the LT1 period. My 173K LT1 just cranked shy of 190psi the other day, the intake was still on don't know if that hurt numbers or not and the thing was babied so I suspect some carbon which could affect sealing, I am working on that and will recheck in a few weeks to see if the numbers improved. Not that 190 is a bad number that is actually very high(not for LT1) typical hotrodder wisdom is anything over 180 means premuim and a perfect tune with aluminum heads, this pig is fine with iron heads and 87 octane. Guys modding old cop cars find crosshatch in the bores at over 150K and cop cars see hour of idling besides the miles they get.

BlkLT1Z28

I have 154k on mine. My best time is a 13.6@104. And thats just with a flowmaster and a b&m shifter. (65 deg.) That is all. So a LT1 being tired @ 130k? I dont think so. Even when I know a guy that has a 225k mile LT1 with bolt on's running high 12's. But I think I know what your talking about when you say your car dies at high Rpms. Mine pulls good to about 5k then it just kinda noses over. I was thinking about that changing mine too. It cant hurt.

"White Knight"

Yea, when i get to around 70mph it feels like she is giving up....and the other car starts pulling on me again.....i hate it. Good thing i run a 1.76 60' or else i'd lose everytime. I jump out front first and get run down the rest of the track.


Should i just jerck one out and test it? See what the seat and open pressures are at??


The thing is i am buying a GSX-R750 this summer, so can't do head and cam....so want something that will let me get into the 12's though--not that just these spring will do that, but i don't think i could without them??

^ see now how come i run a 13.5 and he runs a 13.6 with just exhaust.......it has to be something mechanical holding me back and i really think it's these springs.

BlkLT1Z28

Yeah you could test one, but dont be like some people and push with your hands and be like wow there still really stiff for a lot of miles. It matters if they can controll a valve moving 5000 times per min. which most of them cant. Also if you get some stiffer ones like some LT4's you will notice a slight increase in Throttle response.




And that is the only reason I bought my car because it felt as good as it did. I've pulled the valve covers off, checked the gears, checked the tune, and nothing. Just a high Mileage LT1 Now also note, consistantly(sp?) I will run 13.6x@ 102-103. Depending where I shift. I think everything worked good to get the 104mph. Also I'm a m6 and your 3200 conv. isnt helping you get top end and mph. Thats why you have a 1.7 60'

OutsiderIROC-Z

Mine was that way, and then I changed plugs, and fixed it, until is started doing it again, but his time it pops and jerks around a bit.

"White Knight"

Converter should not effect top end....it is a lock-up, i do agree though the converter is making trap speeds be lower,cause of the slop, but i thought they would be at least stock around 100mph still-with headers and such. I'm not soo much worried with trap speeds as much as e.t.

It's hard to believe you can run .3 faster in the 60' and still get beat my a car that is almost equal....that's what i'm saying.


You mean i can't just test them with my hands??? LMAO

"White Knight"

My power drops off way before 5grand, it's more like 4000 maybe earlier...at least that is the way it feels. I am going to dyno sometime if i don't figure it out.

"White Knight"

plugs and wires have been changed multiple times since then....never did anything. Also new Delteg was added and still nothing. I would say it has to be the valvetrain, cause that's all that hasn't been replaced yet.

Z28Nut

I had my car dyno'd back when it ran 14.01 @ 98.28 mph best and the power dropped dramatically and eratically after 5100rpm. The next spring I did the valve springs, rollers and headers and knocked .7 sec off my ET and gained around 6mph. It was the same, really laid down after 5000. You got a helluva 60ft and an ET close to mine now but your mph is close to what mine was before the springs. I'd go ahead and get the springs, I think that was alot of the .7 I'd sell ya a brand new set of CC 983s but they didn't fit my seats so they probably won't help ya, I got 981s and they fit fine. The LT4s will be fine, too if you're not planning on going with a wild cam in the near future.

"White Knight"

What kindof seat pressure and open pressure are the 981's have? They will need to be machined for larger seats correct? Yea i think i'm just going to do it....it's got to be what is holding me back--just must be to weak to pull the valves shut quick enough and am losing my power.

Since i got this car i would want it to hurry up and shift, it seemed sometimes it accelates faster at 2,500 than 4,000. Maybe it's just in my head and the torque factor, but how the track numbers i have look, i see stock cars running the last 1/8 faster.

I guess i'll do it.

Does the Lyod head and cam packages prices come with springs and such? don't want to go all out till then if i don't have to.

Anyone know the part numbers for LT4 springs, shims, retainers, seats,
. gmpartsdirect.com is probably the best place correct? or is there another like Pace Performance company that has a kit cheaper?

"White Knight"

What about this spring kit from Combination Motorsports it's like $109. I have never used EX componets stuff is it any good? would you say these are better than LT4 springs? I can't find any pressures for these though??

"EX Components 612 Single Coil Extreme Performance Valve Spring Kit
fits stock head without machining, includes lightweight retainers and locks"