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Discussion Starter #1 (Edited)
Hello fellow DC members. In my quest to squeeze out as much horsepower out of my 07 coupe as possible, I decided to let RevExtreme in Tampa Florida put in a cam and install a FAST intake for me. I already had 370+ at the wheels with headers, exhaust, tune, vararam, etc.

Kyle did the work for me and did a fabulous job- they got me 436RWHP and 398 torque. I was absolutely besides myself when I heard and drove it. Unbelievable! However, I had to leave for a 10 day trip the day after i got it back and only got to put 10 miles or so on it. I returned last monday and drove it an additional 40 or so miles, and on thursday, on my way to work, a very loud clanking sound suddenly rang out from under the engine. I was cruising at 50mph in 6th gear at about 1500rpms. I pulled over and had the car off within 30 seconds. Had it towed to RevExtreme, and within a few minutes, they showed me a titanium valve spring split in two- yep, these are the 918's model I found out after the fact that Comp Cam had been having lots of trouble with. We dont know what other collateral damage has been caused. They're pulling off the head tomorrow to check out the piston and other internal parts.

Has anyone had this problem with comp cam springs? and if so, I'd like to hear what happened to you, and also what I might expect in terms of additional damage that may be caused and how to proceed. Additionally, does anyone have recommendations on different valve springs that may be more reliiable? RevExtreme said that CompCam has apparently been handling these part failures well, covering replacement of all failed parts and parts damaged as a result of the failed valve spring and labor. This indeed better be the case. Needless to say, I'm heartbroken to have this nearly brand new vette, with only 3600 miles on it so severely damaged.

Any thoughts or feedback would be welcomed! Tim
 

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Sorry to hear about your problem. Dozens of people have reported 918 spring failures on LS1Tech. Failures go back to about 98-99 or so when they were first released. They fixed them back then and then failures started occuring again in the past year or so.

Hope Comp will take care of you. Let us know.
 

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i would go with the comp 921's

thats if you ever want another comp part on your car:thud:
 

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Discussion Starter #4
Thanks, I'll mention the 921's to RevExtreme. After this experience and that of apparently dozens if not hundreds of other people, the 918's are a potentially lethal aftermarket part for one's engine. If I had only done a little research on my end, perhaps this could have been avoided!
 

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Thanks, I'll mention the 921's to RevExtreme. After this experience and that of apparently dozens if not hundreds of other people, the 918's are a potentially lethal aftermarket part for one's engine. If I had only done a little research on my end, perhaps this could have been avoided!
atleast now people know not to use them

ive read 921's are some of the best on the market :thumbsup:

but there expensive
 

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Discussion Starter #6 (Edited)
For those of you who have a more complex understanding of the LS2, what internal damage may have occurred as a result of this broken valve spring? Is it possible that the piston may not have sustained any dimpling or damage? What about the engine block? Thanks, Tim
 

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Called up my shop in Houston that used 918's. They told me they would replace them if I wanted. But made a point they recieved a bad batch a few months later. Like how yours happened, they said if mine weregoing to fail they would have failed within 50 miles. Really sorry about your engine.

They told me not to be concerned about mine, I may still put the double springs in however.....:crazy:
 

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Sorry to hear about that, hopefully everything is okay. I had my SLP spring fail with just around 1000 miles on it. Just like you, cruising in 6th gear, hear the noise, knocking, etc. Everything was good and that was about 3000 miles ago. Good luck.
 

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Discussion Starter #9
thanks a bunch for your sympathies. I'm just shocked that my new vette is so damn injured. After over nighting the springs, we got the go ahead from Comp Cam to disassemble the engine, remove the head and assess the potential damage so as to begin repairs. They're cooperating and appear to be willing to take responsibility for the damage and repair my car. they want to replace the 918's with their 921 springs. I hope thats a more reliable spring. Kyle at RevExtreme doesnt feel the damage is extensive, but did say that the piston is likely damaged or cracked. I'll know more tomorrow~ Thanks again~
 

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Discussion Starter #10 (Edited)
Bunk~ What damage did you have when your spring broke? Did SLP cover the repair? My mechanic said the whole engine will likely have to be removed to replace the piston. Kills me to hear that, but I guess it must be done.
 

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Bunk~ What damage did you have when your spring broke? Did SLP cover the repair? My mechanic said the whole engine will likely have to be removed to replace the piston. Kills me to hear that, but I guess it must be done.
From two different mechs...one's the local Vette guru, they said no damage but they didn't remove the heads to be sure. The Vette guy did some diagnostics, drove the car and said all is good. So I'm not entirely confident there was no damage but the car still runs strong, no issues, 3000 miles later.

As far as SLP, they would have helped.........not at all. The salesman I dealt with argued with me that their springs never break. Doesn't happen :crazy: I rebuttaled with it has happened at least once being I have a broken spring. Did a search and it obviously has happened before. I posted it on the net and eventually got store credit ($23) for one spring. Sounds like Comp Cams takes care of their folks......SLP would not.
 

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There is a reason why you hear bad things from certain after market suppliers: they stink, we need to boycott them. A salesman arguing with you is insulting.

As to cams/springs etc . . . most of the pro racers, believe it or not, use either Erson or Bullet cam and components. I never heard of Bullet until about 2 years ago. And the Comp nitro cam is big on hype and low on performance.

Pro Stock cars are twisted to about 10300 revs and the thing will last about 25 full runs but the lift and ramp speeds are outrageous - - none I know of use any Comp components. I know most of the ones in NHRA.

Now the fuel cars can be argued as an exception as you build a motor to last <10 seconds. Consider 15,000 psi of cylinder pressure and a few other things that play hell with the valve train and it is all relevant to your car.

Lastly, all cars with cam replacements should have at least two heat cycles before hammering the thing, not everyone is made aware of this one.

I hate to hear of stories like yours because it is another ugly story about a particular part etc. - - and we don't learn from it either. Maybe we shouldn't know but a speed shop, a real one, should know what is good and what is bad.
 

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There is a reason why you hear bad things from certain after market suppliers: they stink, we need to boycott them. A salesman arguing with you is insulting.
You know what, if the guy had at least demonstrated some concern....not for my car but that their spring failed. I understand they don't warranty their product but for 1000 miles, I felt at least pay for the overnight shipping. I didn't ask for much. I'm done with SLP forever.
 

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Bunk,

Remember this lesson and never deal with folks who are rude or have no honor.
Your request was simple enough for sure.

One of my products is guaranteed for life and the fast FWD cars (over 170mph) are hard on them as they are on them the whole 1320; but they too are guaranteed for life and I never ask insulting things. I just ask for the info and replace the product. It has been my experience that this actually increases business too. People like to be treated correctly and they spread the word just as they do when treated incorrectly.

I commend you on your ability to remain as calm as you seem to be about the whole thing. Just try to support the good guys and boycott the bad ones.
 

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If you are putting on comp 921's which are the best in the industry ..IMO

Do you mind asking them their recommended mileage before replacement with your cam specs?

Just something to ask for the future.

20K miles?
 

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Discussion Starter #16
JB- I will definitely ask about recommended replacement time for the 921's. They're arriving today. If you're curious, the specs on my cam are as follows:
232/236, valve lift .595/.601, lobe sep 114.0.

Revextreme took the head off and fortunately found no damage to the head. The piston apparently has one scratch- about 1/4 of an inch long and barely catches the fingernail when scraped. Kyle reassures me that this is completely insignificant and will not be a hazard to leave as it is. Anyone have any opinions on that? I'll get a clear picture of the scratch today.

Comp cam is replacing the 918 set with the 921's for free, in addition to replacing the bent push rod and covering all labor for Revextreme. I'm pretty pleased thus far with their customer service. However, I would highly discourage anyone from getting the 918's, despite their apparent good history and reliability in the past. It only takes one bad spring to potentially destroy your engine. Not worth the risk.
 

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I'm sure with the comp 921's you'll be fine. Good to hear no damage.

Let us know what they suggest on replacement mileage.
 

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Mu question is this: why weren't they utilized in the first place?
 

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Discussion Starter #19
Very good question OldDog- Had I been a little more savvy and informed and did a little research of my own, I may have pushed to have the better springs installed rather than the 918's and learned about the 918's troubled history. However, I just put my trust in the mechanics and let them decide the set up. Now, at least, CompCam is putting up the 921's for no extra charge, which is several hundred dollars savings on my part. I'm just counting my blessings that the car didn't sustain any more damage than it did, other the the broken valve, bent push rod and scratched piston, which they're trying to convince me is insignificant and does not need to be replaced. I'm a little unsettled about this, as I have only had it 4 months, but am going to trust Kyle's judgement at RevExtreme and let him clean up the piston and put it back together for me. I know you're posting here frequently and are pretty well informed- in my shoes, would you have pushed to have the piston replaced as well, or do you too think a single quarter inch scratch that barely catches on a fingernail on the face of the piston is insignificant or potentially hazardous? Thanks in advance :)
 

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In my experience the only "maybe" with the piston is an edge which, in theory, could cause a hot spot. However, if the head is off and the edge is removed you should never know the difference.

This technique works with 14 and 15:1 compressions and I see no reason why it won't work with your engine.

I soon have to check my car for either a spring or pushrod problem as I get a distince miss at about 6200 which is where I shift the car and I am thinking it could possibly be a spring but - - I have been wrong so many, many times before. :lookinup: Like more than once or twice . .
 
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