Comp 918 failure costs an LS1 it's life...
12-08-2009, 07:33 PM
#1
Comp 918 failure costs an LS1 it's life... EDIT: This is NOT my car
A few weeks back a good friend of mine was driving his car when he decided to get on it. He took it to the shift light and just as he let the clutch out after making the shift, he said the car died and made a clicking noise.
He immediately pushed the clutch back in and coasted into a nearby church parking lot. The starter wouldn't budge. I happened to call him just after this happened, and advised him not to try to start it again, as I had a bad feeling already...
He had it towed home and I finally was able to get some time to look into it earlier this week. The #8 cylinder had a broken spring and dropped a valve. There was another spring that was also broken on that bank, but there was still enough of it there to keep the retainer holding on for dear life.
After pulling the head, reality set it. Here are the pics.
A few weeks back a good friend of mine was driving his car when he decided to get on it. He took it to the shift light and just as he let the clutch out after making the shift, he said the car died and made a clicking noise.
He immediately pushed the clutch back in and coasted into a nearby church parking lot. The starter wouldn't budge. I happened to call him just after this happened, and advised him not to try to start it again, as I had a bad feeling already...
He had it towed home and I finally was able to get some time to look into it earlier this week. The #8 cylinder had a broken spring and dropped a valve. There was another spring that was also broken on that bank, but there was still enough of it there to keep the retainer holding on for dear life.
After pulling the head, reality set it. Here are the pics.
Last edited by BriancWS6; 12-09-2009 at 12:27 PM.
12-08-2009, 07:47 PM
#3
It will most likely be a forged 347 setup, especially if the crank is ok. He has plenty of time to think as he saves up some dough.
He bought the car from a member on here back in 07. It already had the cam and springs in it then. All we new was it had the 228 cam package from TSP. The valve covers had never been off during this time. Guess we took it for granted that the guy wouldn't cheap out and get singles to save $100. Duals seem to be the standard with most cams these days. It never crossed our minds to check.
He bought the car from a member on here back in 07. It already had the cam and springs in it then. All we new was it had the 228 cam package from TSP. The valve covers had never been off during this time. Guess we took it for granted that the guy wouldn't cheap out and get singles to save $100. Duals seem to be the standard with most cams these days. It never crossed our minds to check.
kinda similar what happend to me. so i feel for you. 
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12-09-2009, 01:07 AM
#10
I totally agree with you.beginning of this year broke a crane duals on my blk one.#2 exh.vlv.outer luckly vlv. was still hangin due to inner was still intact never dropped the vlv.running prc duals now and might do the same on my 35th.those pics. are scary.
12-09-2009, 01:07 AM
#11
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I bought 243's with comp 921's already on them. I had them checked out by a machinist and they are still good. I have never heard of anyone have a problem with comp 921's.
12-09-2009, 03:24 AM
#12
TECH Senior Member
No need to have single spring phobia. Most of the failures on single sprigs are either:
1- From improper install (not correct height
2- From improper use before reaching operating temps.
3- Spring is used past its capability period, for too many miles without checking pressures.
- A few can be from bad batch but that is not a regular occurance in singles.
All stock LS1/LS6/LS2 etc.. use beehives, and duals will not garantee to save your motor.
Bottom line, once you mod and cam, you have to have a certain amount of regular maintenance and springs have to be checked at least once a year or every 15K miles.
Also upon install, proper geometry, preload and install height has to be done. Otherwise life expectancy of the springs could be shortened.
1- From improper install (not correct height
2- From improper use before reaching operating temps.
3- Spring is used past its capability period, for too many miles without checking pressures.
- A few can be from bad batch but that is not a regular occurance in singles.
All stock LS1/LS6/LS2 etc.. use beehives, and duals will not garantee to save your motor.
Bottom line, once you mod and cam, you have to have a certain amount of regular maintenance and springs have to be checked at least once a year or every 15K miles.
Also upon install, proper geometry, preload and install height has to be done. Otherwise life expectancy of the springs could be shortened.
12-09-2009, 04:39 AM
#13
Duals would not have saved this motor. I agree with Predator, most just slap valve springs in and call it a day. Very few measure the installed height, shim to a seat value and sort out clearances and over the nose force values. Given the time frame of the install, these 918's could have also been from the Comp switch over period.
12-09-2009, 08:25 AM
#14
No need to have single spring phobia. Most of the failures on single sprigs are either:
1- From improper install (not correct height
2- From improper use before reaching operating temps.
3- Spring is used past its capability period, for too many miles without checking pressures.
- A few can be from bad batch but that is not a regular occurance in singles.
All stock LS1/LS6/LS2 etc.. use beehives, and duals will not garantee to save your motor.
Bottom line, once you mod and cam, you have to have a certain amount of regular maintenance and springs have to be checked at least once a year or every 15K miles.
Also upon install, proper geometry, preload and install height has to be done. Otherwise life expectancy of the springs could be shortened.
1- From improper install (not correct height
2- From improper use before reaching operating temps.
3- Spring is used past its capability period, for too many miles without checking pressures.
- A few can be from bad batch but that is not a regular occurance in singles.
All stock LS1/LS6/LS2 etc.. use beehives, and duals will not garantee to save your motor.
Bottom line, once you mod and cam, you have to have a certain amount of regular maintenance and springs have to be checked at least once a year or every 15K miles.
Also upon install, proper geometry, preload and install height has to be done. Otherwise life expectancy of the springs could be shortened.
Running for 2 years on my singles now, going in to replace this spring. 6600 shift point, 218 passes down the 1320 this year alone. As stated above, let it warm up on cold starts and replace/check height at mileage interval and you'll be fine.
12-09-2009, 11:44 AM
#15
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So would failure of a single spring be more likely if the spring was installed at too low an installed heighth, like compressed too much. If it was installed not compressed enough wouldn't that cause a lifter failure as the lifter would ramp over the lobe?
12-09-2009, 12:25 PM
#16
After reading some of the replies I feel some of you must think this was my car. It's not, it is a friends. My car's engine gave out back in April when number 7s ring land let go..
I agree that there is maintenance and precautions that must be taken with a modded car, and I also can't tell you as to how the springs were installed, setup, or how many miles they had on them in total. He bought the car like this, and IIRC, the cam hadn't been installed too long when he bought it. Like I said, this isn't my car, and while he does bring it to me when he needs work done, it can't be my responsibility to keep up with mileage and maintenance. I do the best I can to bring things to his attention if something comes to mind. I'm sure in the future with his next setup, things will be documented closely and checked on regularly.
I do know that he never comes close to beating on his car at all while it's cold. Although the singles are rated at .600 and this cam should be fine, and was fine was several years, it's hard to believe that anyone wouldn't have a little more piece of mind with duals. Would duals have saved this engine? Maybe, maybe not. But I like the odds better vs the singles.
FWIW, these springs have a green stripe on them. I know there were some cases of 918 issues in the past, however, I do not personally know the time frame or the way to identify those particular ones.
I agree that there is maintenance and precautions that must be taken with a modded car, and I also can't tell you as to how the springs were installed, setup, or how many miles they had on them in total. He bought the car like this, and IIRC, the cam hadn't been installed too long when he bought it. Like I said, this isn't my car, and while he does bring it to me when he needs work done, it can't be my responsibility to keep up with mileage and maintenance. I do the best I can to bring things to his attention if something comes to mind. I'm sure in the future with his next setup, things will be documented closely and checked on regularly.
I do know that he never comes close to beating on his car at all while it's cold. Although the singles are rated at .600 and this cam should be fine, and was fine was several years, it's hard to believe that anyone wouldn't have a little more piece of mind with duals. Would duals have saved this engine? Maybe, maybe not. But I like the odds better vs the singles.
FWIW, these springs have a green stripe on them. I know there were some cases of 918 issues in the past, however, I do not personally know the time frame or the way to identify those particular ones.
12-09-2009, 03:24 PM
#18
do you think the green stripe was originally blue but do to oil and heat changed color?
The new 918 appear much more substantial than the old, like the PSI (I think) springs on the dart heads. If one of those broke with a 228, I'd be suprised.
It's hard to beat $255 dual gold springs and ti retainers, locks, and seals.
Best of luck to your friend.
The new 918 appear much more substantial than the old, like the PSI (I think) springs on the dart heads. If one of those broke with a 228, I'd be suprised.
It's hard to beat $255 dual gold springs and ti retainers, locks, and seals.
Best of luck to your friend.
12-09-2009, 04:15 PM
#19
do you think the green stripe was originally blue but do to oil and heat changed color?
The new 918 appear much more substantial than the old, like the PSI (I think) springs on the dart heads. If one of those broke with a 228, I'd be suprised.
It's hard to beat $255 dual gold springs and ti retainers, locks, and seals.
Best of luck to your friend.
The new 918 appear much more substantial than the old, like the PSI (I think) springs on the dart heads. If one of those broke with a 228, I'd be suprised.
It's hard to beat $255 dual gold springs and ti retainers, locks, and seals.
Best of luck to your friend.
So did the earlier 918s have a blue stripe? What color's on the newer ones?
