When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
I decided to address the valve issue in August 2012 by having my heads pulled and sent to WCCH for their stage 2 port job, Del West titanium intake and REV solid stainless exhaust valves and bronze guides.
The Corvette already a Katech Torquer 110 and solid stainless exhaust valves but no port work. So I was freshening up the heads with all new valves and getting their port work done.
Lethal Performance in San Antonio took care of all of the removal and installation of the heads in late September of 2012.
One year and an estimated 3300 miles of street driving after the heads were "fixed" my wife got orders to Yokota AB Japan so the Corvette was put into storage in Dallas, TX - October 2013
Fast forward to April 2016, the Corvette has been in storage in Dallas, TX for 2 1/2 years being started once a month, not driven.
The storage facility was having problems with starting the vehicle so I had it towed to LG Motorsports to be looked at for the no start condition.
They pulled the valve covers and found one of the exhaust valves broken I dodged a bullet big time! They also tracked down the no start to a wiring issue.
I'm not really wanting to start any arguments about what is the best way to go with rebuilding heads but here is what I ended up going with.
I had LG Motorsports head guys install stock exhaust valves and had them install PSI 1511 springs. They also had to replace one intake valve for some reason. They did comment that the guides were "cheap"
Take it for what its worth, that's my story. Pictures are below.
Your solution to your problem is what I did the first time around, so good call.
I fail to understand how a "wiring issue" developed with the car sitting in a storage container. Maybe your car experienced a few "Ferris Bueller's Day Off" joy rides..
Your solution to your problem is what I did the first time around, so good call.
I fail to understand how a "wiring issue" developed with the car sitting in a storage container. Maybe your car experienced a few "Ferris Bueller's Day Off" joy rides..
Corrosion in the harness. They replaced the complete harness. No joy rides.
WCCH typically uses CHE bronze guides. As far as I know they are not considered cheap, but a standard bronze guide commonly used if PM guides are not available. At the time of your build, PM replacement guides were not generally available. Today more shops have access to PM guides, but many top shops still use CHE bronze guides.
sure wish I knew more about this.
seems like the retainer remained but the part almost directly above the retainer broke off?
do wonder what the wipe pattern looked like--perhaps some side loading? perhaps this and perhaps that---many things come to mind.
but the main thing is you came out much better than it could have been.
1st SS valve I have heard of breaking in this engine
sure wish I knew more about this.
seems like the retainer remained but the part almost directly above the retainer broke off?
do wonder what the wipe pattern looked like--perhaps some side loading? perhaps this and perhaps that---many things come to mind.
but the main thing is you came out much better than it could have been.
1st SS valve I have heard of breaking in this engine
Yes the retainer was still there and holding.
I'm not sure about the wipe pattern but I did have them install new LS7 rockers that have the Straub bushing trunion kit. I sent the rockers to a machine shop in Rohnert Park CA to get the tips polished and trued. I read about them and the Straub bushing kit on ls1tech.
Last edited by RWE 427; 07-26-2016 at 06:28 PM.
Reason: changed location of machine shop to Rohnert Park
Yes the retainer was still there and holding.
I'm not sure about the wipe pattern but I did have them install new LS7 rockers that have the Straub bushing trunion kit. I sent the rockers to a machine shop in Rohnert Park CA to get the tips polished and trued. I read about them and the Straub bushing kit on ls1tech.
That is a completely different failure mode than what the "fix' is fixing. So people should take that into account. Freak failures can always occur, and a tip of the SS valve snapping off is definitely strange. Hollow valve, solid, stock, aftermarket, the top end tip like that is all just about the same. This points more towards a freak bad part, or bad install.
Where is the last cap on the intake valve?
That broken part looks like the lash cap with part of the exhaust valve in it, which would explain the failure as the lashcaps go on the intake.
That is a completely different failure mode than what the "fix' is fixing. So people should take that into account. Freak failures can always occur, and a tip of the SS valve snapping off is definitely strange. Hollow valve, solid, stock, aftermarket, the top end tip like that is all just about the same. This points more towards a freak bad part, or bad install.
Where is the last cap on the intake valve?
That broken part looks like the lash cap with part of the exhaust valve in it, which would explain the failure as the lashcaps go on the intake.
That looks too thick to be a lash cap, and you wouldn't use one on an SS intake or Ti "hardened tip" valve anyway - I think what we have here is another case of these aftermarket valves with "hardened" tips failing - just like we've seen with the aftermarket Ti intakes.
As much as people like to crap on the OEM stuff, at least they don't fail like this..
Feel free to correct my assumption.
Last edited by Dan_the_C5_Man; 07-26-2016 at 08:54 PM.
If you notice in my picture the valve on the right of the paired valves is ALWAYS the exhaust. The OP's failure is definately exhaust, as he said.
Right - I believe Unreal was asserting that they put the lash cap from the stock intake valves onto this exhaust valve - from the pictures, that's not what I see.
Last edited by Dan_the_C5_Man; 07-26-2016 at 08:56 PM.
Right - I believe Unreal was asserting that they put the lash cap from the stock intake valves onto this exhaust valve - from the pictures, that's not what I see.
They could have very well done that. If you look close at the broken cap in his hand it sort of looks like I can see an imprint of the retainer's opening where the valve locks are.
Just seems like sharks circling waiting for a SS valve to break. It has happened, it will happen. Parts break.
DSS makes great driveshafts, yet I spun the end right off one. I didn't sit there and bash them and say how DSS shafts suck. I ordered another and moved on. It was a freak failure.
OEM stuff fails, aftermarket stuff fails. Everything fails. People acting like either don't break, or one always breaks are just crazy.
That looks too thick to be a lash cap, and you wouldn't use one on an SS intake or Ti "hardened tip" valve anyway - I think what we have here is another case of these aftermarket valves with "hardened" tips failing - just like we've seen with the aftermarket Ti intakes.
As much as people like to crap on the OEM stuff, at least they don't fail like this..
Feel free to correct my assumption.
I'm not sure about the lash caps, I'm pretty sure they aren't used on the solid exhaust valves.
07-26-2016, 04:26 PM
*Broken LS7 SS exhaust valve...
I dodged a bullet big time! They also tracked down the no start to a wiring issue. 
Pictures are below.
