Broken valvspring.

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Robban 54
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Broken valvspring.

Post by Robban 54 »

Is it posible to say vay this happend? Intakevalv.
SBC 383 Edelbrock heads and cam dur 234/238 lift .359/.356 hydr roler rocker1,6/1,52
Brok on motorway 60mph 2200rpm 1hour.
Streetcar 15000mils max 6500rpm perhaps 30 times.
All old springs and one new is 130lbs on seat.
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Newold1
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Re: Broken valvspring.

Post by Newold1 »

Looks from the pics to be a beehive spring? Please identify the spring brand and approximately what year valve springs. Please identify engine and some specs. Is this a hydraulic roller application or a solid roller or flat tappet? What are the cylinder heads and rest of valve train?

I assume from the breakage of a single spring like that the engine suffered some damage. Have you had that and have you opened the engine yet to survey issues? Sorry for your loss, hope damage is not to major.
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Re: Broken valvspring.

Post by SupStk »

Newold1 wrote: Mon Jan 15, 2018 10:55 am Looks from the pics to be a beehive spring? Please identify the spring brand and approximately what year valve springs. Please identify engine and some specs. Is this a hydraulic roller application or a solid roller or flat tappet? What are the cylinder heads and rest of valve train?

I assume from the breakage of a single spring like that the engine suffered some damage. Have you had that and have you opened the engine yet to survey issues? Sorry for your loss, hope damage is not to major.
Did you even read the original post or just look at the pics? He provided info for 5 of your questions.
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DaveMcLain
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Re: Broken valvspring.

Post by DaveMcLain »

Is it possible that the spring could have had some slight damage from corrosion which caused the problem? It is hard to tell in the picture but that can sometimes happen if the engine/springs sat around for a while in cold weather.
F-BIRD'88
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Re: Broken valvspring.

Post by F-BIRD'88 »

It happened because sometimes valve springs break.

This happens on LS motors often.. Often enough....

Thats why many switch to suitable hi perf dual coil valve springs for hi perf hyd roller cam motors like the LS corvette motors LS3 LS9 etc..

You can too... The dual coil springs help avoid piston valve contact damage if when one coil fails.

Cheaper than pistons..
Robban 54
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Re: Broken valvspring.

Post by Robban 54 »

Thanks for response.
The springs has been in the engine for approximately 5 years.
I have not seen any damage on the springs
It is Comp Cams 26918 beehive spring.
It´s not the one with blue ribbon.
With 7 degree tool steel retainers.
Coil bind,inst height,lift etc is ok.
Only the valve was bent.
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Re: Broken valvspring.

Post by piston guy »

More common on a conical or "beehive" because the load is concentrated in the area of change from straight to conical. right where this one broke. They used to do it 40+ years ago too.
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Re: Broken valvspring.

Post by F-BIRD'88 »

Age has not much to do with it.. But I would at least replace the whole set.

PSI and or PAC springs has better replacements and also the mentioned dual coil valve spring upgrade. Even the GMPP blue stripe spring is a better replacement.


if you are running the valvetain into valve float you are not helping things.
These single coil beehive springs are like radial tires. Great up to the point of .......
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Re: Broken valvspring.

Post by swampbuggy »

Robban 54----valve springs are one of the parts in an engine that are on the (list of parts) which are most likely to fail (especially in a high perf. application). One should just plan on replacing the valve springs after so many cycles, miles, etc. (before they should fail) . This is just the way to play it safely . Mark H.
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Re: Broken valvspring.

Post by Newold1 »

I am not going to spend anytime defending my reading or questions, no need the OP has answered 4 of the 5 quite well in his second post.

Iam also very glad to hear from the OP that a bent valve was the only real significant damage. With the intake side this is more prevalant because the intake side tends to let go and drop the valve with the piston near the top of the cylinder piston travel and hence tends to bend the valve , drive it up and leave it stuck in the guide ABOVE a point where it drives into the piston and causes catastrophic engine damage. If the exhaust spring breaks it drops the exhaust valve into the cylinder generally close to the bottom of piston travel in the cylinder leaving the entire valve out of the guide fully into the cylinder with the piston traveling up and you can imagine what happens from there!

I was pretty sure when he posted the pics, I knew the spring and the approximate age. I knew this because this was the exact spring I and many others in the aftermarket started having serious problems with back starting about 2008 right after it was introduced and I was having my own issues with this spring on LS builds. I also saw the same type of problems from an early aftermarket same basic spring from a large industry valve spring manufacturer.

I would like to say at this point Comp realized the failures and problems and changed the manufacture and design of this spring and since then the scope , reason and magnitude of this past problem has been eliminated in that part number to my understanding.

The real reason for this problem in this beehive spring as well as some others in the industry stems pretty much from how the spring wire was wound during manufacture. If you take one of this period years particular beehive spring and stand it up and look down the top opening of the spring you will see that the center of the top opening in the spring at the retainer opening you will see that the center of the bottom opening in the spring is not directly under the top opening center. You might ask, why does this matter! It matters because as the spring is compressed the top of the spring is off center with the bottom of the spring and as the compression distance increase the wire of the spring section at the break points is being bent back and forth horizontally as the valve stem going down in the guide tries to align the two openings. Obviously valve spring wire tends to end and twist as it compresses but not in this fashion. That type of unintended bending moment at that point heats the wire and weakens it. Just like bending a paperclip wire back and forth until it breaks. I as well as hundreds of other LS aftermarket beehive spring head users and other beehive valve spring users had this breakage show up and had lots of damage and grief. Why does it not happen on all beehive springs is because not all beehive springs are made with this defect. This is backed up by the millions of beehives that are in use today in millions of vehicles. I don't think you will see this issue with any of Comps beehives today and other major spring manufacturers also eliminated this condition and beehive spring usage in the aftermarket in general is much better today than back then.

If you are using beehives today in your builds and performance uses, just take the springs and do this top down look. If you see this top to bottom misalignment-STOP-send them back if you can or can them and get another good set of beehives. I won't go into the long detail of how this problem was identified just let me say a few good valve spring experts and some good spintron testing found and proved the problem.

To the original poster if you choose to stay with a beehive spring for your application then check the new ones and make sure they don't suffer out of the box with this problem. If it were my call I would switch to a good conical spring or a nice set of straight doubles. JMO
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Re: Broken valvspring.

Post by pdq67 »

I will say that no more than a spot of sweat off your fingers over time will rust, thus corrode a valve spring and it will break.

And even a drop of water on a spring that rusted it!

Seen it happen.

pdq67
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Re: Broken valvspring.

Post by HDBD »

I hope to see some lower pressure dual conicals in the near future. Kind of like radial tires with a high speed rating :wink:
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Re: Broken valvspring.

Post by geraldtson »

I would never consider a beehive valve spring to start with? If that's what it came with now's a good time to have learned something.Look where it broke. Cut new spring seats and install good quality conventional springs!
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Re: Broken valvspring.

Post by swampbuggy »

Yep PDQ67 this is why you sometimes see engine builders wearing thin rubber gloves don't you reckon ? Warp ----do you guys wear them ???? Mark H. :D
Robban 54
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Re: Broken valvspring.

Post by Robban 54 »

Thank you for all the good answers.
Seems like I will look around for new springs.
Are there any better springs conical or beehive that can replace my old ones?
Regards Robert
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