blitzu

I recognize that picture I wish I would have taken pictures before and after with them on the motor... ohh well maybe next time I have the valve covers pulled.

KGjevre

magnetic drain plugs

I just wanted to add the info about the magnetic drain plugs to this thread. If you search you will find lots on info on this, but I think it can be sumarized as:

2006 Z06 does not have magnetic drain plugs (except for maybe late build ones).
2007 Z06 has magnetic drain plugs
2008 Z06 has magnetic drain plugs until it was deleted from the build sometime in January 08.

Greg Gore

Having a magnetic drain plug does not mean the needles were not pecking and gouging away at pistons, cylinder walls and nicking the titanium rods before the magnet caught them. If I had needles on the magnet I would pull the pan for a look inside. I bet the pan and the piston skirts are pecked up inside from the needles being hit by the spinning crankshaft and thrown at everything in the crankcase. Get those rockers out of there fast.

KGjevre

Is not the point of the dry sump to keep the crank out of the oil?

Greg Gore

What about loose needle bearings falling down through drainback openings in the block on the way down into the pan? They get hit by the spinning crankshaft for a while before they can go anywhere else.

Greg Gore

A dry sump actually serves several purposes but the main features are it allows more oil capacity, allows the engine to be mounted lower in the frame because typical drysump pans are shallower which increases ground clearance, gives greater control over the oil by insuring an uninterupted supply of oil to the engine during hard cornering and braking. And for safety in racing applications; an engine failure does not result in all of the on board oil ending up on the track, or providing fuel for an oil fire.

markbrown

the thread should be renamed the 2007 and up watered down version of the ls7 broken rocker arm needle bearings issue.

so it will not deteriorate the original bad a$$ 06 z's like mine.

410shooter

Was there a change on the 2008 to fix the problem?????

blitzu

I hope that's the case, I really do. But, have you put in magnetic drain plugs in your motor? Spend the $4 to get two of them, put them in for an oil change or two... and if you have a half hour pull the valve covers to double check. It does zero harm, requires no special parts or expertise, and only requires I believe a 10mm socket. Check the sides of each rocker... if one is hallow then you have a problem. Most owners report they noticed NO difference until they saw the bearings attached to their drain plugs.

blitzu

No. It's the exact same part, manufacturer, and part number since 2006.

Greg Gore

There needs to be a better solution than this. If it were me I would not want to take a chance on wondering if I have the "lucky" rocker arm or not and risk driving around out there with rocker arm needles bouncing off the crankshaft and hitting everything in the crankcase while they hunt for the magnetic drain plug. What do you do? Keep pulling needles of the magnet until all 33 are accounted for?

Greg Gore

Discover needles on your drain plug at your regularly scheduled oil change? No problem, GM will pay to replace the failed rocker arm and you simply keep a crib sheet handy to update your current needle count... drive and purge strategy. At each regularily scheduled oil change you simply instruct your oil change technician to save the needles if any more show up and cross them off the list I guess until you have all 33 accounted for.

This is actually a genius decision cost-wise on the part of GM. Install magnetic drainplugs and sell the idea to owners and prospective buyers that the magnet is all you need to ensure your LS-7 is protected. Much less expensive than pulling the pan to clean them out of the crankcase. Idea is to hope a magnet will attract and pick them out of the oil while you drive your car so you can be confident you are doing the right thing.

426 Hemi

Thinking out loud here---has there been any positive proof that the rocker arms losing the needle bearings are causing the broken valve springs, i.e. do ALL broken valve spring engines have a gutted rocker arm too?

Or are we looking at a totally separate issue.

CORVETTE007

Ya know, I just checked my engine build date ('08) and it was 010, so January 10 2008, although the sticker in the passenger side wheel well states Jan 03 2008. Just seems weird that the engine was built after the car at least appears to have been built.

Again the Jan 03 2008 sticker is in the inner front wheel well on the passengers side. On the drivers side I can't make sense out of the grease pen writing.

LGR

"Or are we looking at a totally separate issue" Yes

LGR

But not a broken spring.

CanadaGrant

I guess if GM admitted there was something wrong they would then have to recall all the vehicles instead of just fixing them as they break. What would be nice though is if they would actually come out and state that if I want to prevent this from happening and use after market or modified stock rockers my warranty won't be voided. I don't mind paying out of my own pocket for a little piece of mind but if they are going to jerk me around come warranty time then I don't care if there are bearings in the pan or not.
Grant

Greg Gore

In a well sorted and developed competition engine the valve spring is the single most critical part without exception. It is the one single thing that always limits the amount of lift we can have and the maximum RPM we can safely turn the engine. If we exceed the RPM limits of the spring they simply fatigue and break. If we could find a way to get yet better cleaner wire for valve springs we could make even better valve springs which would enable us to make more power which is the reason we continue research world wide in that area. We pay over $1000 for a set of springs now and only race them one time. Just for comparison the springs in the LS-7 are made by Mubea (Muhr Bender in Germany) and GM probably pays less than a dollar a piece for them. You can buy one at your local dealer for $5. This is getting into atom smashing a little on a stock engine that only turns 7000 RPM but for the sake of discussion if you drove the car at high RPM with a loose rocker arm from lost needles the excessive lash would hammer the valve spring possibly fatiguing it. Fatigue always results in loss of spring load. A spring that has lost enough load will always break if you run it hard. The only way you could ever know this for sure is you would have to pull the covers and measure each spring to see how they compare with each other with a simple portable spring rater. I would not run the engine hard with one that was 10% lower that the others. You need 100 lb on the seat and 300 lb over the nose to maintain valve train control on this engine at 7000 RPM.

This is the company that supplies the springs for the LS-7
http://www.mubea.com/english/produkt...r_ventilf.html

02impactblue

So who has the best quality valve springs for the ls7?

CanadaGrant

The problem isn't the valve springs. It's the crappy rockers with the pressed in tin inserts. Hell... I'm from Canada and even I got grip on this one....