SloppyRob

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Why did one of my crane duals fail after 4months and 6k miles? Im pretty pissed right now. Was sitting in traffic on my way to work, accelerated and noticed something was up. Car was sputtering and idling like ****. Managed to drive 20 miles back to my house. I could hear something rattling around on the driver side so i pulled the valve cover. Well what do you know i snapped a ******* spring. NOT Happy. Lucky I went duals though or i'd be pretty screwed right about now. I'll post a pic in a few.

P.S. My car sees barely any high rpms....WTF?

94form2000z

iTrader: (10)

Wow that sucks. Maybe just a bad one.

and to think people say duals give false sense of security. Glad to know it kept your valve off the piston personally. Good luck to ya.

SloppyRob

Well i'll find out if there's any valve piston damage when i pull the spring. hopefully not. THis sucks.

MyLS1Hauls

iTrader: (2)

They do give that....if his engine was running high rpm, it would have had some definite issues. I've personally seen single springs break and never have PTV issues at low rpm. Funny though how people are breaking these dual springs just as much as singles. I was definitely considering using Crane duals, but now if I go duals they will be Patriots.

Boostaholic

iTrader: (4)

What cam?

94form2000z

iTrader: (10)

That is true with the high RPMs. Luckily he wasn't getting on it adn hopefully he doesn't have a bent valve or tore up guide. I just read that Crane changed the material they were using on there springs due to degrading spring pressure caused by higher RPMs. Look for Fireball's post.

Check his sig it is in there unless it is not updated.

AdamSS

iTrader: (3)

Man, I don't get this.... 4 months, and 6K miles ??? I was gonna pick Patriots over Crane anyways, but this **** shouldn't have happened on either spring. Not after 6K miles. F11 cam doesn't have a crazy lift anyways, and its rate is less agressive than XE-R...so wtf ???? poor Crane quality control ??????

SloppyRob

It's my exhaust valve spring that went. .593 exh to be exact. Its an FMS F11 cam thats in there. For the past month or so I've been daily driving the car to work which is a long drive. Maybe this is what caused the failure. Regardless im still pissed. It hasen't seen over 5k rpm in a while. I just ordered another set though. Need to get it up and running. I guess i'll just do the broken one until i have the time to replace all of em. Whats the best way to change the spring without dropping the valve into the cyl. I have a compressor so i just need that fitting for the plug...or should i just crank the car over until it looks like the piston is at TDC for that valve?

AdamSS

iTrader: (3)

Just compress the cylinder where the broken spring is....

SloppyRob

Where can i get the fitting for the spark plug hole to use the compressor?

AdamSS

iTrader: (3)

You can get it in any car store (pepboys, autozone, Murray's) you can even get it in sears.... Just make sure you tell them what kind of car you have. different car makers, have different spark plug sizes....

SloppyRob

Cool, thanks.

marc_w

The TDC method works great, and it's free.

Sorry about the problems though. I'm real nervous about my 918's. I too have a long commute each day.

PREDATOR-Z

I'm quoting a Crane article release.

My name is Mark Campbell and I am VP or R@D at Crane Cams. Eight months ago, we (Crane) decided we wanted to improve our 144832 valve spring to minimize load loss at extreme RPM. The spring has what we consider to be the best harmonic characteristics for its intended use (this is a result of physical design characteristics, not material), but we could see that some LS1 guys were operating at RPM levels above 6500RPM frequently and that was drastically accelerating load loss. We merged an improvement of the 144832(changed the material to a much improved alloy) with the design of some new springs that used the same wire diameters. When the new versions of the 144832 (identified by a blue stripe and a yellow stipe) came in, we had to Spintron test them for quality. They worked beautifully and had only 1/3 the load loss of the original 144832's. In fact, this material is so lightly stressed that these springs will take .700" lift when installed at 112# @ 1.800" (and still have .060" additional travel). In fact, they can be shimmed .060" to give 133# on the seat and still take .640" lift safely. This is all with keeping the great harmonic characteristics and low noise signiture to eliminate false KR!

Swamee

I broke a REV Dual valve spring last week, exhaust side, cylinder #7, .598 lift xer lobe. I called them and they told me i was 'almost' putting the spring in cold bind with that kind of lift. The proper way it should have been installed with to have had the valve spring seat machined so the installed height of the spring is 1.820"-1.830"......the factory spring installed height is 1.750"-1.760"
REV is willing to send me a complete replacement set of springs, but I have to get the heads machined properly.

JoeyGC5

iTrader: (24)

Not to alter everyone elses' focus, but what kind of warm up time does the car see?

TEA Brent

What cam are you running, I've seen that spring break before.

2 SLOW

Were you using a shim??

99-LS1-SS

Personally I never drive my car unless it is completely up to operating temp. I don't know if that will help me in the long run but I would rather be safe than sorry.

SloppyRob

no shims and the car does get warmed up before drives.