Broken valve spring...what to expect?
Broken valve spring...what to expect? We finally started tearing apart the motor in my 01 SS tonight. The car previously had a lot of blow by and was running and smoking really bad. We removed the valve covers and found that one of the valve springs (cylinder 6) is broken at the top. The seat is still in place and it doesnt look like the valve fell in but im guessing the valve might of hit the piston and caused damage.
The spring is a goldish color and has a blue stripe down the side but im not too sure what brand they are they are just single springs. Do you guys think the heads are going to be damaged. I have a new ls1 short block thats going in but my worry right now is damage to the heads/cam. What might i expect monday morning when we pull the heads off? Also could this be why the car was puking so much oil out?
The spring is a goldish color and has a blue stripe down the side but im not too sure what brand they are they are just single springs. Do you guys think the heads are going to be damaged. I have a new ls1 short block thats going in but my worry right now is damage to the heads/cam. What might i expect monday morning when we pull the heads off? Also could this be why the car was puking so much oil out?
I doubt the heads are damaged. What you are going to see, is a small eye brow looking indention on the top of the piston and the valve is going to be really clean/machine looking on the outside. It more than likely did no serious damage to the head, but may or may not have bent the valve a little bit. If the valve is straight I would just replace the valve spring you should be just fine.
I know from personal experience on a recent repair I had on a 2008 express 2500 van with a 4.8l.. A valve spring broke and slightly touched the piston top but it didn't bend the valve, put it back together with new valve springs and it ran great.
Thanks,
Craig
I know from personal experience on a recent repair I had on a 2008 express 2500 van with a 4.8l.. A valve spring broke and slightly touched the piston top but it didn't bend the valve, put it back together with new valve springs and it ran great.
Thanks,
Craig
You can usually determine a bent valve by doing a leak down test on that cylinder.
If it will pass a leak down test you're probably good to throw another spring on it and keep rolling. Usually it's standard procedure for me to pull the heads for a spring break but the damage doesn't look too bad on yours. If it were mine and it didn't leak air out of the valve I'd run it.
And if you want to keep the lightweight benefit of a beehive valve spring without the worry of breakage, do yourself a favor and buy a set of PSI 1511ML springs. Best beehive on the market and they do NOT break.
If it will pass a leak down test you're probably good to throw another spring on it and keep rolling. Usually it's standard procedure for me to pull the heads for a spring break but the damage doesn't look too bad on yours. If it were mine and it didn't leak air out of the valve I'd run it.
And if you want to keep the lightweight benefit of a beehive valve spring without the worry of breakage, do yourself a favor and buy a set of PSI 1511ML springs. Best beehive on the market and they do NOT break.
The setup i would say has about 20k miles...the car had about 90k miles when it was installed and is now at 111k. The engine wasnt making any noises like knocking or ticking when it ran last...just your typical sewing machine valve train noise the ls motors make. Of course it had blow by and was smoking alot and had no power. We also found a broken spark plug on cylinder 8. The cam is an ms3 i believe from what i was told. Im looking at a set of dual valve springs to upgrade the current springs. Thanks for the info guys Im hoping for the best...the heads will go to the machine shop tuesday hopefully and then we will start assembling the new motor so hopefully the cars running again here in about 2 weeks.
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You can usually determine a bent valve by doing a leak down test on that cylinder.
If it will pass a leak down test you're probably good to throw another spring on it and keep rolling. Usually it's standard procedure for me to pull the heads for a spring break but the damage doesn't look too bad on yours. If it were mine and it didn't leak air out of the valve I'd run it.
And if you want to keep the lightweight benefit of a beehive valve spring without the worry of breakage, do yourself a favor and buy a set of PSI 1511ML springs. Best beehive on the market and they do NOT break.
If it will pass a leak down test you're probably good to throw another spring on it and keep rolling. Usually it's standard procedure for me to pull the heads for a spring break but the damage doesn't look too bad on yours. If it were mine and it didn't leak air out of the valve I'd run it.
And if you want to keep the lightweight benefit of a beehive valve spring without the worry of breakage, do yourself a favor and buy a set of PSI 1511ML springs. Best beehive on the market and they do NOT break.
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Joined: Mar 2012
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From: Park City, UT
I have seen at least a dozen LSX engines with broken valve springs with no damage to the valve or piston. If you have a bore scope you can look through the spark plug plug hole and see if the valve has hit the piston.
Better as in better harmonics @ high rpm, light weight, cheap (relatively speaking for what they offer), and they will work with stock locking / retaining hardware.
Anything I build anymore that's below .640 lift gets PSI's. I haven't used another valve spring in almost 2 years.
You can usually determine a bent valve by doing a leak down test on that cylinder.
If it will pass a leak down test you're probably good to throw another spring on it and keep rolling. Usually it's standard procedure for me to pull the heads for a spring break but the damage doesn't look too bad on yours. If it were mine and it didn't leak air out of the valve I'd run it.
And if you want to keep the lightweight benefit of a beehive valve spring without the worry of breakage, do yourself a favor and buy a set of PSI 1511ML springs. Best beehive on the market and they do NOT break.
If it will pass a leak down test you're probably good to throw another spring on it and keep rolling. Usually it's standard procedure for me to pull the heads for a spring break but the damage doesn't look too bad on yours. If it were mine and it didn't leak air out of the valve I'd run it.
And if you want to keep the lightweight benefit of a beehive valve spring without the worry of breakage, do yourself a favor and buy a set of PSI 1511ML springs. Best beehive on the market and they do NOT break.
