Ricky218

I'm sorry, I should've been more clear. I had the factory heads CNC'd, bronze valve guides, new valves, rocker arms, push rods etc.

MTPZ06

Gary, saw this in the FS section... https://www.corvetteforum.com/forums...ls9-heads.html

Doesn't look like he's on your list.

Gary '09 C6

Mike,

thanks...I've updated the list.

The moderators removed the "sticky" from this thread when the ZR1 & Z06 sub-forums were merged...and I have been unable to get them to restore it.

Appreciate your helping me keep it alive...the list has good, important information for all of us keeping tabs on the LS9 (and by inference LS7) valvetrain matters, and I am committed to maintaining it.

Gary

MTPZ06

Yeah, I thought this was a sticky. More than a few things were screwed up with the merge...hopefully things will get sorted out eventually.

Gary '09 C6

ttt for Katech repair offering...


https://www.corvetteforum.com/forums...at-katech.html

Gary '09 C6

updated the list for the report I submitted on my own car:

https://www.corvetteforum.com/forums...t-of-spec.html

Wm.Hacker

Just had a friend put a cam in his I think 30000 mile ls9. He stated he did a wiggle test and they all the checked out ok.It was a 2010 by the way.

Gary '09 C6

Unfortunately, the "wiggle test" is not as accurate as a bore gauge w/mic...the wiggle test is only an indicator (IMO).
Based on the reports on the list, it would not surprise me if some of those LS9 intake valves are out-of-spec...

jdwk

Has anyone had theirs measured and were all in spec? What all has to be removed to do the check? If the heads have to be removed, then I am guessing you might as well replace the guides even if they are in spec. Even the labor just to remove the SC and valve covers is probably not cheap, but probably worth the peace of mind.

KurtsZ06

I replaced the heads on my Z06 last month, car has 20k miles. Never tracked. Oil changes were frequent by previous owner, every 2500 miles.
Every valve was within spec, intact all but two were at New spec. No signs of wear on the valves, coating was fine. I had AHP send a pair of bullet proof heads, ported and polished. New double springs, new intake and exhaust valves and new rockers. I replaced all of the lifters as well.
I did it to be proactive, no sense taking a chance on destroying the engine. With my luck it would happen in BFE. Now I have a set of perfectly good heads to work on myself. I’ll keep them up to 50 - 60k miles then swap them out.

As an aside, I’m using Amsoil and a quart of Prolong into a 10qt oil system. I’m a firm believer in the oil additives that reduce wear. I’ve learned my lesson with additives as I use them in my twin engine airplane. Those engines put out no less than 80% power and operate in extreme conditions. Since I started using the additives, wear measured at overhaul has been minimal. At $45,000 per engine, that saves lots of money and peace of mind.

c05v3tt3

So you use one of these every oil change?

jdwk

I found a YouTube video where a Z06 owner said he had a friend with a 2010 ZR1 with 23k miles that dropped a valve and grenaded the engine to the tune of a $20k repair bill, which doesn't appear to be on this list.
There just weren't that many ZR1's built, so even a few incidents is pretty discomforting. I've never had a -$20k day, but I'm imagining it would be very bad.

What have people been paying to have them checked and/or replaced?

KurtsZ06

Yes, every oil change. It’s an extra $20, the advantages far outweigh the cost. If it’s good enough for a $40,000 airplane engine or $500,000 turbine .. it’s sure as heck good enough for the LS7.

KurtsZ06

i can only speak for my recently purchased Z06. I paid $300 during the pre buy to have the valves checked. The Indy that did the check was really only able to give a crude assessment since the heads didn’t come off. He pressurized each cylinder, then with the spring compressed did the wiggle test. In my opinion it is a far cry from an accurate measurement, but at the time it gave me a look at what could have been a valve way out of spec.

The total cost of replacing my heads with which should be close to a ZR1 head replacement was $5900. I did the labor myself. I also bought the ARP install kit, couple of header baskets and intake gaskets. I understand most shops want $1200 to do the job. Heads could be much less, $2000, if bronze guides and OEM rockers, lifters and springs are used. I replaced with upgraded parts due to failures I’ve read about, especially with rockers and lifters.

c05v3tt3

And the LS9 too?

jdwk

Thanks for the info. I watched a video of the wiggle test and since just the valve covers have to be removed, it should be the same for a ZR1 as a Z06. If you want to do it yourself though, it's looking like an easy $300 in tools to get an accurate measurement. Those are some pricey heads, but like you said, you could go much cheaper. I am guessing the cheapest option is just to press in new guides, but most probably choose to upgrade the heads and valve train at the same time.

VetteVinnie

Gary '09 C6

jdwk, if this ZR1 is a CF members's car and said owner has actually reported it here on the forum, please direct me to that report and I will add it to the list. ..thx Gary

jdwk

I put a comment on the youtube video, but he didn't reply and his youtube messaging is turned off. I'll let you know if he does.

Joey D

Bump on and old thread since this comes up often...