avisenna

Hi all

Long story short: I have a 07 C6 Z06. Dropped a valve like a year ago- now getting ready to put in a new motor. Does anything else besides the full long block need to be replaced?

I know when a valve takes a **** it takes the block, piston, everything inside the motor with it...but what about everything outside the motor?

Just wondering if I I need to replace the Dry sump tank, lines, oil cooler, or radiator, etc

Appreciate any recommendations. Prefer to do it right the first time

ClothSeats

I can't think of anything off hand that needs to be replaced due to a dropped lifter, but there are a few questions that come to mind about some things that weren't mentioned in your post:
1. Does your new long block have OEM GM cylinder heads or aftermarket heads that address the valve problem (such as AHP heads)?
2. Does your new long block have OEM titanium connecting rods? Some owners have reported failures of these rods due to adjacent rods rubbing against one another. Not all owners have reported this, but I am just asking the question, because if you feel you want to make this new engine last, this may be the time to install forged steel connecting rods.
3. Did you give any thought to the type of valve lifters in your new long block? The OEM arrangement is individual lifters held in alignment with plastic lifter trays. There are many examples of this arrangement lasting a long time, but there are also reports of the lifters getting loose in the lifter trays and then they start to turn. This results in failure of the roller on the end of the lifter, which also wipes out the cam surface in short order. An optional arrangement is to install link-bar type valve lifters. They keep the lifters aligned without the need for the lifter trays. I have no information as to which arrangement is better, I am just stating that now is the time for you to give this some thought and become satisfied that you are happy with your choice.

I am curious to know if the valve that failed was an intake or exhaust valve. Do you mind saying?

2k Cobra

I would replace anything external that touched engine oil, as you mentioned above. I'm sure others will chime in..
Good luck on getting it going again! 2k

double06

You will probably need to flush the dry sump tank and any oil cooler stuff. Flush radiator if oil got in there. You need to see what you find in the motor there may be some salvagable parts. Also clean out manifold as metal could have bounced back up in the intake there. Check the exhaust and cats see what might have come out. It depends what happened here, some are just more catastrophic than others like - it just went poof at idle at the stop light --- or at 6,000 rpm.

shane p

Clean the oil tank out. You can take it out of the car and take the tank apart and wash it out good. The lines going to the tank should be cleaned or replaced, there are some places in the lines where small particles can hide. Same thing with the oil cooler and those lines. You may want to replace the cooler. I had a professional place flush it out, I keep getting junk out of it for days after they did it.

avisenna

Thanks all- yea I figured it would be wise to atleast clean everything that oil passes through...possibly the radiator too because the car was spitting coolant from the exhaust (so it likely took a coolant jacket as well)

Valve dropped around 4000rpm, local driving, light throttle so I guess it shouldn't be too bad but we'll see

@ClothSeats I'm not doing anything fancy- just replacing the motor with a new crate LS7, so it'll have new OEM heads, rods, lifters.
Not sure which valve dropped but I can find out.

ClothSeats

Avisenna, if it's not too much trouble, it would be interesting to know which valve broke. It seems that it is usually the exhaust valve. They are smaller in diameter than the intake valve, which should make it stronger due to less leverage on it, but on the other hand, the exhaust valve is hollow, where the intake valve is solid, so that may be the main issue right there.

Good luck with the new engine project. I bet she will purr (growl) like a tiger.

AzDave47

Early LS7s (to some time in 2008?) tended to drop exhaust valves as the wall thickness QA around the sodium filled are tended to vary quite a bit. GM made a change to the exhaust valves after that and seemed to solve the exhaust valve problem. Later LS7s tended to drop the intake valve more frequently.

psp6158

Crate ls7 with OEM heads... I think most would agree to have them fixed while the motor is out so you are not doing this again in the future.

shane p

Those heads could be junk as well.

avisenna

Wait- you mean GM never fixed the problem on LS7 heads since 2007?

Like if I buy a brand new LS7 today from GMPP it will still have the head issue?

I thought they had fixed it at some point...otherwise it would mean they've been selling new LS7 heads, LS7 crate motors for the past 10+ years with the same valve guide issue

AzDave47

GM said the problem was mid-2008 to early 2011. Given new crate motors in 2013 had measurements taken and the brand new crate engines had the valves not concentric with the seats, ALL LS7s are subject to the valve guide problem. Linamar did the LS7 heads. They also did the C7Z e-difs and did not put the right amount of tranny fluid in them so the first 5000+ were subject to dif whining and some failed before they got home from museum delivery. Linamar web site touts how they are a Preferred Corvette supplier. It apparently doesn't take much.

LS7s in the Camaros also have the same problem.

ClothSeats

To my knowledge, GM never fixed the valve failure issue even though they knew about it. It seems that if they admitted to the problem, they would then be obligated to go back and fix every one made, which they didn't want to do. For current owners, the best course of action is to just replace your heads with AHP or another reputable brand for peace of mind.

Bingo002

I just went through this with my own car (and yes, mine fractured a coolant jacket as well). Mine blew at 45k miles at WOT near 7000 RPM. Wound up going with Texas Speed for a long block and ported heads with new guides, I have about 5k miles on it (big cam and heads) and I haven't had any issues with it.

1. No, GM never fixed the heads, you will need to take them off the brand new long block, and have them reworked.
2. The oil tank will need to be cleaned extensively as well as the two lines going from it to the oil pan, but neither should need replacing.
3. I replaced my oil cooler and lines as they're not too expensive to buy used and they are not easy to clean.
4. I did not touch any of the cooling system aside from just draining and refilling.
5. I bought a new intake manifold from Texas Speed as mine had plenty of metal in it and no amount of washing could get it all out.

As for parts that were still salvageable on mine, it wasn't much.
1. 1 good piston
2. 7 rods that needed to be recoated
3. The crank (all of my rods/bearings were still intact, so only the counterweights have scoring).
4. Oil pump that needs to be taken apart and cleaned.
5. Oil pan was fine, but the pickup tube took about 30 minutes of cleaning to get all the metal cleaned out of the edges of the screen.

Those are all the big hitters, practically everything else in the rotating assembly was damaged.

SivaSuryaKshatriya

Hey I'm in the same situation so I wrote a list of parts and their corresponding GM part numbers to make life easier for the next unlucky guy:

- Engine oil tank, outlet hose: part #15210117
- Engine oil tank, inlet hose: part #15210122
- Engine oil tank, auxiliary tank: part #12629422 *
- Engine oil tank, engine cooler line seal (4x): part #15217990
- Oil cooler: part #15803358 **
- Oil cooler lines: part #20828695 **
- Intake manifold: part #12686561

* GM manual says to replace auxiliary tank, but supposedly it's actually hollow inside and can easily be washed out... your choice
** I'd recommend just getting a new oil cooler kit like the Improved Racing one

Let me know if I'm missing something and I'll add it.