Attention Valve Spring Failures/Concerns
Team Owner
Joined: Jun 2005
Posts: 46,295
Likes: 2,596
From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
"What's funny, is the bore spacing has remained the same as my 265 cid '56 Chevy small block. Probably has something to do with the automated production equipment." JerryU
Could be the equipment and the cost to replace. But it might also be that the longevity of the engine without issues has been evident with that bore spacing, so maybe the thinking is, why change it.
Could be the equipment and the cost to replace. But it might also be that the longevity of the engine without issues has been evident with that bore spacing, so maybe the thinking is, why change it.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 35,044
Likes: 12,410
From: NE South Carolina
^^
Could be! It went from cast iron with thick cylinder walls to very thin aluminum walls and pressed in steel liners. Great engineering!
Could be! It went from cast iron with thick cylinder walls to very thin aluminum walls and pressed in steel liners. Great engineering!
Last edited by JerryU; Oct 5, 2020 at 10:26 AM.
Race Director
Joined: Aug 2016
Posts: 12,840
Likes: 10,252
From: Garden Valley CA
^^^
Frankly in addition to the one pic we have of a failed spring my "guess" is this is a metalogical defect, i.e. inclusion, etc in a small number of springs versus a batch heat treated improperly is the Tonawanda plant probably checks samples. Easy to do with a measure of the spring force at installed height and at max lift.
Frankly in addition to the one pic we have of a failed spring my "guess" is this is a metalogical defect, i.e. inclusion, etc in a small number of springs versus a batch heat treated improperly is the Tonawanda plant probably checks samples. Easy to do with a measure of the spring force at installed height and at max lift.
A surface hardness test or microstructural analysis is needed to determine proper heat treat.
As you said it is most likely a defect in the material although it is possible that the heat treatment is too "hard".
Last edited by RKCRLR; Oct 5, 2020 at 11:27 AM.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 35,044
Likes: 12,410
From: NE South Carolina
The modulus of steel doesn't significantly change (if at all) with heat treating so a spring rate test wouldn't be an effective screen unless the heat treatment was way off. The heat treatment would need to be either so soft that the springs took a permeant set during testing or so brittle that they broke during testing.
A surface hardness test or microstructural analysis is needed to determine proper heat treat.
As you said it is most likely a defect in the material although it is possible that the heat treatment is too "hard".
A surface hardness test or microstructural analysis is needed to determine proper heat treat.
As you said it is most likely a defect in the material although it is possible that the heat treatment is too "hard".
Modulus of elasticity is essentially the same for mild steel and heat treated 4340! That's the problem of using high strength steels in most bridge designs and submarines where max allowed bending is a key design criteria. However assume if a spring, was in the annealed condition, it could yield at say max lift loads.SIDEBAR
We spent a lot of time (plus our own and the Navy's money) developing 140,000 psi yield welding materials for subs to replace the typical 80,000 psi yield HY-80. When the design issues of max flexing were finalized the additional stiffeners that would have to be added offset the strength advantages!
Last edited by JerryU; Oct 5, 2020 at 02:34 PM.
Safety Car
Joined: Dec 1999
Posts: 4,723
Likes: 1,461
From: Virginia Beach, VA & Port Charlotte, FL
Never steel liners, iron. The better liners have a higher grade iron, ductile I believe. The "cheap" iron liners were the bane of the LS7. They allowed detonation cylinder liner cracking very easily. Not sure of the iron grade for the LS2s.
Le Mans Master
Joined: Apr 2020
Posts: 6,380
Likes: 3,294
"That" was the one design problem on my 280SL - sort of. It has a cast iron block with an aluminum head. Pumping 200hp out of 170 cuin meant changing the head gasket every 30,000 miles like clockwork. After 4 heads, I recovered every $ and waited for my C8. I did know that it would be 2 decades later. But what a daily driver. Btw, it was one of the rare 4on the floor! Zs use to cry as they read my license plate. A former life. Hopefully over time my C8 will fill that void.
Last edited by C8J; Oct 6, 2020 at 08:23 AM.
Team Owner
Joined: Jan 2008
Posts: 30,894
Likes: 1,189
From: chicago
my duramax has had liners in it for 20 years
their big claim was some kind of hardening in the first 20-40 thos wall
and semi trucks use push out liners for 30+ years,and they go 1mill + miles
somewhere these springs were made wrong,its just odd they are breaking at 4-50 miles,and not breaking at dyno test or loading them on the transport trucks
their big claim was some kind of hardening in the first 20-40 thos wall
and semi trucks use push out liners for 30+ years,and they go 1mill + miles
somewhere these springs were made wrong,its just odd they are breaking at 4-50 miles,and not breaking at dyno test or loading them on the transport trucks
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Michael S. Palmer
Instructor
Joined: Mar 2016
Posts: 206
Likes: 142
From: MD's Eastern Shore
Le Mans Master
Joined: Apr 2020
Posts: 6,380
Likes: 3,294
Like bending a paperclip back and forth, it doesn't take many times, but not on the first few. Guess that those above 500 should have some feeling of relief if reports hold up. No report of any reaching 500 nd finally opening up and having a spring failure - yet.
Race Director
Joined: Aug 2019
Posts: 12,351
Likes: 14,185
From: Central Illinois
"That" was the one design problem on my 280SL - sort of. It has a cast iron block with an aluminum head. Pumping 200hp out of 170 cuin meant changing the head gasket every 30,000 miles like clockwork. After 4 heads, I recovered every $ and waited for my C8. I did know that it would be 2 decades later. But what a daily driver. Btw, it was one of the rare 4on the floor! Zs use to cry as they read my license plate. A former life. Hopefully over time my C8 will fill that void.
Le Mans Master
Joined: Apr 2020
Posts: 6,380
Likes: 3,294
Problem wasn't the Gasket directly. Forgot if it was the head or the block (I could go look have 1 of each still in storage, but no point), but the cooling water would erode an outer wall and eventually bypass the gasket and wala!
Race Director
Joined: Aug 2019
Posts: 12,351
Likes: 14,185
From: Central Illinois
Friend of mine had a Honda Civic in the late 80s that looked like the coolant just rinsed away part of the aluminum head, no fixing it, the metal was gone. New head was the only fix.
Le Mans Master
Joined: Jul 2010
Posts: 6,591
Likes: 2,648
From: Lancaster, PA
my duramax has had liners in it for 20 years
their big claim was some kind of hardening in the first 20-40 thos wall
and semi trucks use push out liners for 30+ years,and they go 1mill + miles
somewhere these springs were made wrong,its just odd they are breaking at 4-50 miles,and not breaking at dyno test or loading them on the transport trucks
their big claim was some kind of hardening in the first 20-40 thos wall
and semi trucks use push out liners for 30+ years,and they go 1mill + miles
somewhere these springs were made wrong,its just odd they are breaking at 4-50 miles,and not breaking at dyno test or loading them on the transport trucks
Safety Car
Joined: Oct 2015
Posts: 4,128
Likes: 616
From: St Louis Area IL
Back in the C4 ZR-1 days there was a person at Bowling Green who would redline the cold engines as he parked the new cars. Needless to say the engines suffered and the employee was gone. Perhaps, we have a similar situation here. It is odd how some cars hold up very well and few others fail with very low miles. Or, it could be a small batch of bad springs...
Race Director
Joined: Aug 2019
Posts: 12,351
Likes: 14,185
From: Central Illinois
Drove mine 92 miles valve spring cracked and fell into cylinder. Fortunately there was no other damage after pulling the engine. Dealer replaced all of the springs Build date 8/28
Burning Brakes
Joined: Aug 2019
Posts: 1,088
Likes: 236
In my business, I build high performance motors, mainly Harley-Davidson type V-Twins, big inch strokers, and Japanese 4 cylinder roadrace stuff too. I have since the '70's. Just mentioning, so my reply may have more validity than a landscaping contractor.
If springs were used from a supplier that had quality issues, problems could surface during any time, including after the vehicle warranty period expires. You may not be entirely out of the woods with a thousand miles, 10 thousand miles or even 30!
The longer you go, the less likely a failure, but that does not mean immune.
It was determined that Subaru had a valve spring related issue that could have effected my '13 Crosstrek. This was 2 years after the warranty expired and my car had over 60K miles. Subaru contacted me and did a free replacement of all the valve springs and gave me a new car loaner for a week. This was over a year ago. Their logic was a broken spring could result in power loss or worse and cause an accident resulting in injury or death.
My thoughts are GM should do the right thing and replace springs on all cars using products made from the spring supplier until the quality improved.
If springs were used from a supplier that had quality issues, problems could surface during any time, including after the vehicle warranty period expires. You may not be entirely out of the woods with a thousand miles, 10 thousand miles or even 30!
The longer you go, the less likely a failure, but that does not mean immune.
It was determined that Subaru had a valve spring related issue that could have effected my '13 Crosstrek. This was 2 years after the warranty expired and my car had over 60K miles. Subaru contacted me and did a free replacement of all the valve springs and gave me a new car loaner for a week. This was over a year ago. Their logic was a broken spring could result in power loss or worse and cause an accident resulting in injury or death.
My thoughts are GM should do the right thing and replace springs on all cars using products made from the spring supplier until the quality improved.