How many miles can you expect from valve springs

["Turbo-T"]

Maybe it's me but it seems I can find quite a few folks who have valve spring issues that cause upper rpm stumbling. Are TR's common for the valve springs notoriously going weak?

 

[longball]

yes - search and you will see...........

 

["Turbo-T"]

Ok...of curiosity, does it have to do with the engine cylinders being pressurized due to boost?

 

[SCOOBY DOO]

Valve springs go soft over time. They're just another item that wears out.

 

[bison]

I've got a set of old 941 comp that have been used on 3 engines and run over 40000 miles. About a year ago I tested them against a new out of the box set of 941's and they were stronger. I have a high mileage set of 26918's that a lot of people had trouble with but they are still good too. I've got 6000 miles on a set of PAC 1203 that aren't giving me any problems either and they are on a cam that has way more intensity than what anyone posts about here. Those that have problems probably checked nothing and assumed they had enough spring.

 

[fitz3820]

New GN bumper sticker: "Weak Springs Save Cams"

 

[williamsGN]

Check with Nick Micale who has built dozens of engines and he will explain how they are not a wear part unless you are having valve float, RPM issues, etc. They are not wear out parts like timing sets, etc.

http://www.turbobuick.com/forums/threads/timing-chain-valve-springs.367378/#post-2933762

http://www.turbobuick.com/forums/threads/when-to-replace-valve-springs.52702/#post-424479

 

[bison]

New GN bumper sticker: "Weak Springs Save Cams"

They actually hurt roller cams if the roller loses contact with the lobe.

 

[phil_jordan]

After reading those threads, the question remains left the table(specifically the second thread). There's some helpful info in there, but i hate it when a thread is never "solved." I normally try and close out threads that I start with coming back saying "its fixed" or "still having issues" or something. Hell, after reading the symptoms, Im almost sure that I need some valve springs.

 

[forcefed3.8's]

A friend of mine had a set of 941's that were over 10years old, and had 20,000 miles on them. When doing head gaskets, I pulled them to test them, 100 closed, 300 open. He was seeing valve float. After swapping springs, the car runs the same at 23psi than it did previously on 27psi.

 

[fastblackracing]

After reading those threads, the question remains left the table(specifically the second thread). There's some helpful info in there, but i hate it when a thread is never "solved." I normally try and close out threads that I start with coming back saying "its fixed" or "still having issues" or something. Hell, after reading the symptoms, Im almost sure that I need some valve springs.

It is tough to know for sure because you dont have a broken or mangled part to see. It comes down to experience and shall we say aquired knowledge over time. Most people dont have a spring tester so you really dont know what you have for pressure like bison said. Find yourself some" spintron valve spring" videos on youtube to watch.... there interesting to see

 

[bison]

A friend of mine had a set of 941's that were over 10years old, and had 20,000 miles on them. When doing head gaskets, I pulled them to test them, 100 closed, 300 open. He was seeing valve float. After swapping springs, the car runs the same at 23psi than it did previously on 27psi.

QC isn't one of comps highest priorities.

 

[bison]

It is tough to know for sure because you dont have a broken or mangled part to see. It comes down to experience and shall we say aquired knowledge over time. Most people dont have a spring tester so you really dont know what you have for pressure like bison said. Find yourself some" spintron valve spring" videos on youtube to watch.... there interesting to see

Anyone trying to make power with any engine and doesn't check spring pressures and verify installed heights shouldn't be touching anything. "I think" and "I thought" doesn't mean chit. Would you want a doctor who was going to operate on you thinking he's doing something right or actually knowing WTF he/she is doing?

 

[williamsGN]

Bison, what is your take on Nick's comments on spring replacement ? I have no idea on the status of my springs. This motor was rebuilt with the best of everything.. forged pistons, arp, etc. No idea what springs, but I know i can spin 5300 at low boost. I would rather not wipe a cam on the possible advantage of new springs and from what I read, stock replacement springs won't net an advantage over the possibility of cam damage.

 

[bison]

Bison, what is your take on Nick's comments on spring replacement ? I have no idea on the status of my springs. This motor was rebuilt with the best of everything.. forged pistons, arp, etc. No idea what springs, but I know i can spin 5300 at low boost. I would rather not wipe a cam on the possible advantage of new springs and from what I read, stock replacement springs won't net an advantage over the possibility of cam damage.

I used to run the sealed power number for lt1 replacement. I shimmed them to get the pressures I wanted. 90 on the seat was plenty for a stock cam. I ran ran 105-110 on the seat with replacements. If the car won't pickup out the back the springs are suspect. If everything is fine then more won't help. I've seen 180whp gains @5500rpm switching from weak springs to the correct spring for the application . There was zero gain below 5000 on the same engine after the spring change.

 

["Turbo-T"]

Check with Nick Micale who has built dozens of engines and he will explain how they are not a wear part unless you are having valve float, RPM issues, etc. They are not wear out parts like timing sets, etc.

http://www.turbobuick.com/forums/threads/timing-chain-valve-springs.367378/#post-2933762

http://www.turbobuick.com/forums/threads/when-to-replace-valve-springs.52702/#post-424479

Thanks. I understand valve springs gob ad with time, just it seems I've seen more asked on them with the TR crowd than some of the other boards I frequent.

I'm pretty sure I've got a valve float issue attributed to weak valve springs. The car pulls like a mofo until around 4000, then it seems power starts dropping off, around 4800 it sounds like it's popping/sputtering...sounds like a "dut-dut-dut-dut-dut-dut" when it does...like a rev limiter was installed but there is no rev limiter. You can even watch videos of me racing the car....you can see it looks like it pulling like a bat out of hell off the line but it doesn't appear to increase much more in speed. Car only picks up 17-18 mph in the last 1/8 mile of a 1/4 mile track which I know is not good/should be at least 20 mph.

I have no idea what springs are in it, much less how old they are or even if they were set up correctly. Engine was supposedly redone before I got it but I can't verify who did the build to ask. I have the cam card that goes to the cam (old Postons grind - in my sig) I've tried the usual of changing filters, coils, plugs, compression checks, fuel psi checks, unhooking waste gates to not make boost, etc.

Maybe it's time to throw the damn thing on a dyno and see where it start laying down and by how much?

 

[bison]

Thanks. I understand valve springs gob ad with time, just it seems I've seen more asked on them with the TR crowd than some of the other boards I frequent.

I'm pretty sure I've got a valve float issue attributed to weak valve springs. The car pulls like a mofo until around 4000, then it seems power starts dropping off, around 4800 it sounds like it's popping/sputtering...sounds like a "dut-dut-dut-dut-dut-dut" when it does...like a rev limiter was installed but there is no rev limiter. You can even watch videos of me racing the car....you can see it looks like it pulling like a bat out of hell off the line but it doesn't appear to increase much more in speed. Car only picks up 17-18 mph in the last 1/8 mile of a 1/4 mile track which I know is not good/should be at least 20 mph.

I have no idea what springs are in it, much less how old they are or even if they were set up correctly. Engine was supposedly redone before I got it but I can't verify who did the build to ask. I have the cam card that goes to the cam (old Postons grind - in my sig) I've tried the usual of changing filters, coils, plugs, compression checks, fuel psi checks, unhooking waste gates to not make boost, etc.

Maybe it's time to throw the damn thing on a dyno and see where it start laying down and by how much?

I would change springs and verify pressure/heights since you don't know what's on there and you have symptoms of a spring pressure problem

 

[SloGN]

what type of ignition system ?

 

[m233roller]

Springs are like other parts they can and do go weak and they DO break. As Brian (Bison) stated he has done this and that with different springs but you can take it to the bank he has tested pressure on ALL of them and gets them set up at the right installed height. Plus knows what pressure he needs for givin cam set up.
Turbo -T above, it does sound like you are floating at 4800. I had one stock cammed engine do that exact same thing every time right at 4800 and it was the springs. I was floating the valves. When checked on a spring tester, they were about 55 to 60 closed and right at 160 open. About 7 years ago I had Al Dicksen at HRD ( a well know cylinder head guru who has never done anything in his life but cylinder heads) Use to even do heads for NASCAR and the likes. Anyway he redone a set of Champion irons for me and installed ALL Ferrea valve train parts, with spring locator cups, titanium retainers, the whole bit. I ran them on a 109 engine with forged pistons, stock turbo crank, polished stock rods, biller main caps and a 206-206 billet roller cam with spring pressures at 140-145 closed and right at 340-345 open with a 1.750 installed height and all the other supporting junk. Ran the hell out of it for 32,000 miles and it would pull hard to 5400 - 5500. NO problems what so ever (except had LOTS of trouble with those junk comp. cam roller lifters) went to the new Morels as soon as they came out. Built a new forged, girdled 109 last winter, took the heads back to Al for a freshening up and a good check out. We tested ALL the Ferrea springs and they were all still within 5 to 10 lbs. of original pressure. Now one thing I use to do at Al's advice, when I put the car away for the winter and it was just going to sit for several months I'd unload the springs. In other words I'd unbolt the rocker arm assembly's so they had no pressure on them. Put the freshened up heads on this new engine and with only acouple thousand miles on it was just putting down the street at 35 mph and just like someone flipped a switch it went to running on 5 cylinders and had some clacking in the valve train going on. Was real close to home so babied it home and pulled the right valve cover and Bingo!! busted valve spring. So just goes to show you parts even springs just wear out. Fatigue, bad spring ? Who knows. Throwed new springs in it and It's still running great. Oh cam is now a 210-215 ductile roller from Mike. I'm sure Brian can tell you ALOT more story's about springs than I but if you have dought pull the springs off ( not that big of deal) if it is a big deal to you,( LEAVE it ALONE) and get them checked out but you'll have to know or check your installed height.
Here's a pic. below of busted spring.

 

[Scott Atk]

A lot of vendors put kits together with K-Motion springs because they are inexpensive. I've found these springs have a very limited service life (K-750's are a very common entry level roller cam spring).