Broken valve spring theory?
Thread Starter
Safety Car
Joined: Sep 2002
Posts: 4,161
Likes: 12
From: San Diego CA
Broken valve spring theory?
I have a H/C combo on my 03 Coupe. It is not a daily driver and sometimes it will sit for 2 weeks without having the engine started.
I broke a valve spring and bent a valve a few weeks ago.
Since the engine was not started and the springs did not get any lubricant during that time, is it safe to say that the lack of lube caused or contributed to the busted spring?
I broke a valve spring and bent a valve a few weeks ago.
Since the engine was not started and the springs did not get any lubricant during that time, is it safe to say that the lack of lube caused or contributed to the busted spring?
Thread Starter
Safety Car
Joined: Sep 2002
Posts: 4,161
Likes: 12
From: San Diego CA
Hopefully the new springs (and valve) that I just installed will last a lot longer!
I suppose there are are lots of Vette owners in the snowbelt who don't start thier cars for months at a time and don't have any problems.
I suppose there are are lots of Vette owners in the snowbelt who don't start thier cars for months at a time and don't have any problems.
Last edited by jmzvet; Dec 29, 2005 at 09:53 PM.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Valve spring failure is typically caused by fatigue. Fatigue is a function of material properties, number of cycles and stress state. So, it depends on how your springs are setup (installed height), your open height (how much you are compressing) and how much you drive the car. In addition, running the springs hard when cold can also contribute to their demise.
Racer
Joined: Dec 2003
Posts: 331
Likes: 1
From: Black Forest Colorado
How much cam do you have in your car? I got a little crazy with mine earlier this year, too much lift and not enough valve spring, broke 2.
Purchased a new set of springs that were designed to handle the lift, no issues ever since.
Purchased a new set of springs that were designed to handle the lift, no issues ever since.
Race Director
Joined: Dec 2000
Posts: 19,304
Likes: 85
From: San Diego CA
My 68 dropped a valve because of spring binding at high revs (bad choice of springs) and bazookad a cylinder wall and head. However, in your case, I'll bet the spring was flawed at the factory. What did Andy say?
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Race Director
Joined: Aug 1999
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From: GARDENA Ca, State Of Konfusion
St. Jude Donor '05
Originally Posted by vettenuts
Valve spring failure is typically caused by fatigue. Fatigue is a function of material properties, number of cycles and stress state. So, it depends on how your springs are setup (installed height), your open height (how much you are compressing) and how much you drive the car. In addition, running the springs hard when cold can also contribute to their demise.
Maybe material failure!!
Le Mans Master
Joined: Oct 2005
Posts: 7,088
Likes: 1,829
From: Metro Detroit Michigan
Originally Posted by vettenuts
Valve spring failure is typically caused by fatigue.
Originally Posted by vettenuts
In addition, running the springs hard when cold can also contribute to their demise.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
There have been some problems with the REV springs in the past, and I think it was attributed to material issues. A surface flaw will obviously accelerate the failure.
Very hard metals, that are susceptible to cracking, have a glass transition temperature, i.e., a lower temperature that will promote cracking. The farther from the glass transition temperature you are the better, so with aftermarket springs which tend to be much harder than stock I always make sure my oil is at 180 before running them too hard.
Very hard metals, that are susceptible to cracking, have a glass transition temperature, i.e., a lower temperature that will promote cracking. The farther from the glass transition temperature you are the better, so with aftermarket springs which tend to be much harder than stock I always make sure my oil is at 180 before running them too hard.
Drifting
Joined: May 2003
Posts: 1,715
Likes: 1
From: cAshburn VA
Spring theory, hmm, didn't I take that in Physics?
A well known way to break a spring is to run up the RPMs before the oil gets circulated and up to temp. With a cam or high ratio rockers you really dont want to move until the OIL (not coolant) temp is around 120. Realisticly, I guess 100 is more reasonable. Hey, sometimes I gotta get to work! Defiantely nothing over 3k rpms until the oil temp is north of 170.
If that spring is rated for .600" lift, that is usually assuming it is properly oiled and at operating temperature. If you run a cold spring up to 4 or 5k rpms, you rolls the dice you takes your chances.
Not saying that's what happened, just a thought on a probable scenario.
Go down to 'Canes on Mission Beach get a pint of Pete's Wicked, watch the sunset and reflect on this wisdom...
Then go to Cheetah's and forget about that old broken spring!
Man I miss San Diego!
A well known way to break a spring is to run up the RPMs before the oil gets circulated and up to temp. With a cam or high ratio rockers you really dont want to move until the OIL (not coolant) temp is around 120. Realisticly, I guess 100 is more reasonable. Hey, sometimes I gotta get to work! Defiantely nothing over 3k rpms until the oil temp is north of 170.
If that spring is rated for .600" lift, that is usually assuming it is properly oiled and at operating temperature. If you run a cold spring up to 4 or 5k rpms, you rolls the dice you takes your chances.
Not saying that's what happened, just a thought on a probable scenario.
Go down to 'Canes on Mission Beach get a pint of Pete's Wicked, watch the sunset and reflect on this wisdom...
Then go to Cheetah's and forget about that old broken spring!
Man I miss San Diego!
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Originally Posted by IFLUBYU
Man I miss San Diego!
Haven't been there is a number of years, and we definitely are lacking in the Mexican food arena here in the northeast. Although I think the outdoor heaters at Casa de Bandini would have a hard time keeping up with the snow 
Melting Slicks
Joined: Mar 2003
Posts: 3,116
Likes: 10
From: Macomb MI
Rev 116 springs = Junk
Do a search here and on LS1tech. I cant tell you how many people have had this happen to them. I recently had a customer that had one last 46 miles with the so called "new and improved replacements"
Phil
Do a search here and on LS1tech. I cant tell you how many people have had this happen to them. I recently had a customer that had one last 46 miles with the so called "new and improved replacements"
Phil
Racer
Joined: Aug 2004
Posts: 482
Likes: 80
From: Florida, Tampa Bay
Rev Valve Springs are JUNK
Rev Valve Springs are JUNK. Please see following thread. I had mine for less than a couple of monthes and they failed. I got new ones from Rev and they failed. Put the Crane dual springs on and have had no problems for about 5000 miles. My tuner sent the broken springs back to rev and politely asked why they had failed. He purchased many parts from Rev for his ported and polished heads and thought he had a pretty good relationship with them. They gave him a bunch of BS like, we don't know what the profile of the cam lobes are, how high he reved it etc. etc. He went over all my specs with them and they still had no answer. That is Crap and he is no longer purchasing rev parts after a 3 to 4 year relationship. A company that won't stand behind it's products and renames the same old crappy parts with a new # does not deserve our business and shouldn't be in business. 
http://forums.corvetteforum.com/show...958&forum_id=1
http://forums.corvetteforum.com/show...958&forum_id=1
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Sounds like they have some serious material issues. All of the really good clean spring steel comes from Japan. That's where most get their steel from for valve springs including Crane, PSI, etc.