Radguy

That's why I asked.

BADZ

What I said above beats having to replace the whole engine. Just think of it as "cheap insurance"...

PatriotZ

0Randy@DRM

95 percent of the time we use the stock valves for road race use. It is up to the customer to make the call.

Randy

0Cunningham Motorsports

being the exhaust valve is much smaller then the intake the weight difference is not great going from a hollow stem to a solid stainless, i believe the difference is like 10 grams which is nothing with a valve spring with over 400 open pressure.... the major weight saving is needed in the intake valve department, which is a large 2.200 valve, on top of that the factory valve is a titanium... so going to stainless intake valve over ti valve is a huge weight penalty... i run the the solid stainless exhaust valves in my personal c6 z and i road course quite alot with no problems at all, my car revs clear to 7400 rpm without issue

andreas g.

I replaced mine and had some head portiing done while they were off the car. I R&R the exhaust valves with one piece SS units, put duel patriot springs on and also installed CHE rockers. It's called peace of mind, or bullitt proof the heads. $2500 is a lot cheaper then a $14,000 motor. RPM did the work. BTW while my car was being done a stock Z06
was towed in with the # 5 cylinder blow out the side of the motor. You Guess it. Exhaust valve head was gone.

C5 Frank

Has anyone tried to keep track of what year cars this has happened to? I mean are we not to say it could be a bad batch of valves? There were a bad batch of rockers in '07. A bad batch of valvesprings in late '06 and early '07.

0Randy@DRM

This is a good idea. But it's really not going to help much at all. I got word a 09 rocker arm came apart in the southern hemisphere.

Give me a year or so and I can have a picture of a broken aftermarket part from every company and a rocker failure in every year.

To the OP, buy it, drive it, have fun!!!

Randy

BSSN

Didn't one vendor or someone say they had torn down 15 z06's and every one of them with over 10K miles had excessive (out of normal limits) tolerances on the exhaust valve-guides?

What has KaTech observed on stock motors when spec'ing this clearance?

RPM?

There really seems to be some conflicting information here regarding the durability of the most appealing aspect of one of GM's "halo cars". I am still unsure what I want to do with my income for 60 months and would like to know what I am getting into if I go the Z06 route.

Also, forget warrenty. It shouldn't break. I would rather have a product manufactured correctly and with good R&D and testing behind it that is unlikely to break than to buy something proven to have issues--that has a warrenty. It's the difference between pride of ownership and "just another possession of mine". I take pride in my hobbies, as it's more of an experience and a passion than transportation--I have transportation. I want something to enjoy!

jschindler

This subject has been analyzed to death already - just do a search. Like most problems, it's real for those who have had it happen. I know quite a few Z06 owners and not a single one of them has had a problem. I'd love to know the % who have had problems. I'll bet it is a very low number.

But Z06 owners tend to do more track days, and drive their cars like....well, like someone who paid and extra $25,000 to get 505 hp would be expected to drive. S*&%t happens when you push the envelope. I used to own Cigarette boats and loved to go out in the bay wave jumping. Every two years I could expect to replace outdrives. Not because they were flawed, but because I loved wave jumping

Mr. Gizmo

When it happened to you were you running a Stock Tune?

ranger1

This is really funny, as my 07 Z, has 26,000 miles. No issues, it was built in March of 07... I change the oil every 3,000 miles..

I am just waiting for it to go...

Garry

0Myhardtop

Here is another input....

How about this: do what ever you want.

If you want to sit back to wait and see, then "vaya con dios"

I've seen racers beat on their Z with no issues while others who use their Z for groceries drop a valve and vice versa. The crap is all over the place.

I didn't sit back and waited, I took care of my heads and a good thing too, 4 of my 8 exhaust guides were beginning to take a crap.

Thanks,
Carlos

AMGPilot

Carlos,

What did you do to prevent exhaust valve and rocker arm failure?

Just curious what my options are and what price range we are talking about.

Thanks

KLLRVET

No, but a tune doesnt wear guides or break valves

mirage2991

No but it voids the warranty which covers the said valve
drop.
Jessels aren't bullet proof either, I have seen those brake too.

you are looking to get an answer that nobody has and are asking for proof of absolute flaw on gm's behalf which nobody has.

MTIRC6Z

I've said it before and I guess I'm about to say it again...people who are so fearful of this sort of 'flaw' should give consideration to upgrading the oiling system.

Katech doesn't change out the stock exhaust valves or stock rockers when they do one of their complete engines, BUT they do make changes to the oiling system...hmmmmm, maybe there's a message in that

Cheers, Paul.

abnrngr

so,, are you saying that Katech has known this and didn't let everyone know? i don't think they would do that

Radguy

I think what Paul is saying is that Katech feels the stock rockers and exhaust valves are fine and they don't see the need to change them on their built engines.

Correct me if I'm wrong, but they do however recommend upgrading the oiling system for people who track thier cars especially if R compound tires or racing slicks are used.

1stZ

I lost my first motor with 17,xxx miles & ~40 rr track days ('06-'8) . 2nd motor was built with durability in mind. Upgraded to are dry sump, jesel rockers, stainless steel exhaust valve, forged pistons, etc.... 2nd motor lasted with only 20k miles & 18 rr track days. FYI, each rr track day have a minimum of 3hrs actual run time on the motor. 2nd motor also was run a handful of times at 190+ mph. Lost the 2nd motor just recently so I haven't had a chance to see exactly what went wrong.