Z/28 Heads

[Fifedogg]

They have found 2012+ heads already out of spec so don't believe everything you hear...

[2SSRS@Gen5diy]

I will run the car for a year then get a set of new heads and send them out to get done the right way, and cut them down to get to 11.5/1 add a cam at the same time, need to add 100HP.

[X25]

Originally Posted by 2SSRS@Gen5diy

If you over rev the motor you drop valves its a known fact, that was some of the issues not all of them but most, if you plan on turning past the red line you need a good head guy to set them up no 2 ways about it.

That's not the cause of this issue. The valvetrain simply fails and drops a valve. It actually (usually) happens during low RPM drive; the valve gets lowered, and simply stays there during low speed action.

I did own a '06 C6Z06, and drove it hard including track days until I sold it at 41K miles. I also owned a '13 Z06, and did not have any issues until I sold it (at ~ 6K miles) with most of the miles at the track. In both cases, I kept everything stock, and nothing happened. In my opinion, changing the cam or doing such other mods to LS7 is a big risk. Even GM stated they got max out of LS7. If you will need to mod the engine heavily, you might as well go with aftermarket heads (not even just modified stock heads) and lower the redline a tiny bit.

FYI, the head work was about $900, so it is not too expensive to get the heads reworked; not that I would like to do so...

[2SSRS@Gen5diy]

Originally Posted by X25

That's not the cause of this issue. The valvetrain simply fails and drops a valve. It actually (usually) happens during low RPM drive; the valve gets lowered, and simply stays there during low speed action.

I did own a '06 C6Z06, and drove it hard including track days until I sold it at 41K miles. I also owned a '13 Z06, and did not have any issues until I sold it (at ~ 6K miles) with most of the miles at the track. In both cases, I kept everything stock, and nothing happened. In my opinion, changing the cam or doing such other mods to LS7 is a big risk. Even GM stated they got max out of LS7. If you will need to mod the engine heavily, you might as well go with aftermarket heads (not even just modified stock heads) and lower the redline a tiny bit.

FYI, the head work was about $900, so it is not too expensive to get the heads reworked; not that I would like to do so...

your right on when it happens, but i still know what i want to do and its a lot more then $900 LOL.

[Dutchman427]

Richard @ West Coast Cylinder Heads did mine and he did one hell of a job. Great guy to deal with and if you have questions, he will answer them. I know I didn't pay $900 dollars to get them ported! It was quite a bit more! When I called about getting my LSA heads ported this past month, it runs about $1,725.00.

[blessedhellride]

lordy, i wish they would have resolved this issue, some serious coin for such a problem......

[2SSRS@Gen5diy]

Originally Posted by Dutchman427

Richard @ West Coast Cylinder Heads did mine and he did one hell of a job. Great guy to deal with and if you have questions, he will answer them. I know I didn't pay $900 dollars to get them ported! It was quite a bit more! When I called about getting my LSA heads ported this past month, it runs about $1,725.00.

I know Richard for more then 20 years, and they do good work, but i have some in mind that did a set of heads for me that are still going, only thing with this guy is if i send him a set today i will have them back after CF6. LOL

[Da Mammer]

I happen to be one lucky son of a b**** then...

I don't have a z/28 but I do have an lsx 454 motor that has the ls7 heads. I got it in fall of 2012. I'm now on my second 454 motor because of the valve guide issue, and now my second motor is doing it too. But I'm trying to keep a positive attitude about it so I'm gonna send em out to be fixed this winter, since I have no warranty left on the engine (after a grand total of ~8k miles total between them both). It gives me an excuse to CNC the heads in the process, so what the hell, why not. But very frustrating to say the least.

And no I did not race my car on any track, and I have a rev limiter set at the specified 6500rpm so no abuse over What this engine should be far more capable of handling.

[NC_SS]

Considering there are no known failures in the Z/28 heads yet, I'd say that it is a good sign, and the Camaro engineers felt confident enough to slap an incredible 100,000 mile warranty on the thing speaks to the confidence of the new heads as well.

As one other user stated above, Hennessey said with their first Z/28 they found that the heads had been completely redone from the factory compared to the Z06's they had been formerly doing business with.

I'd say keep it stock and beat the shit out it

[blessedhellride]

Originally Posted by NC_SS

Considering there are no known failures in the Z/28 heads yet, I'd say that it is a good sign, and the Camaro engineers felt confident enough to slap an incredible 100,000 mile warranty on the thing speaks to the confidence of the new heads as well.

As one other user stated above, Hennessey said with their first Z/28 they found that the heads had been completely redone from the factory compared to the Z06's they had been formerly doing business with.

I'd say keep it stock and beat the shit out it

[Zslash28]

Originally Posted by NC_SS

Considering there are no known failures in the Z/28 heads yet, I'd say that it is a good sign, and the Camaro engineers felt confident enough to slap an incredible 100,000 mile warranty on the thing speaks to the confidence of the new heads as well.

As one other user stated above, Hennessey said with their first Z/28 they found that the heads had been completely redone from the factory compared to the Z06's they had been formerly doing business with.

I'd say keep it stock and beat the shit out it

I for one would like to know specifics on what has been done to make the Z/28 heads different. For me, my car needs to remain stock for now. If I ever modified the car, I don't want it to be because of a stock part failure. Just going by what Hennessy says, might be good for some, but to have someone break it done would be better.

[Blownhotrodder]

Nothing, same part numbers as Z06 LS7's. It will be interesting to see how things turn out with the Z28's guides.

[lmcgrew79]

A friend of mine's 2013 Z06 lost a motor around 8k miles. The 07 he had before that lost went around 30k miles. Luckily the was both unmodified.

[X25]

It will take a few years for us to know. These cars are not usually daily driven, and even if so, they are usually a 2nd or 3rd car, if not 5th. In other words, it will take time until a substantial number of Z28s rack up considerable amount of miles.

When the issue popped up around 2007 for C6Z06, it was quickly dismissed until around 2009-2010, when owners started thinking the sky is about to fall.