Originally Posted by JoesC5

I hope my new PRC265 heads with Ti intakes and SS exhausts with dual springs(up to .675" lift) using my stock cam, is the fix. From what I've read in other posts, bounce is not a problem unless you go above 6800 RPM. Very seldom do I go above 6500 RPM, so I'm not worried.

Originally Posted by Beach Bum

My question if anybody knows..... has any 10,000+ mile plus SS valves with bronze guides combinations been tested at each valve for guide wear via the wiggle test or any other testing ?

That should tell us a lot.... if they are showing significant wear, then perhaps the problem has not been fixed, if they are checking out well within spec.... then I would guess its problem solved. We know with the stock configuration, wear on most valves was either on its way to being out of spec or already there....if no significant wear is evident on the SS+Bronze combination.... then it seems logical the world is a good place and we can all live happily ever after.
(I realize this may have been answered in other threads, but I haven't been reading them.... sorry if repetitive)

I hope SS+Bronze has solved the problem.... if not, I just threw away thousands of dollars.

btw, anybody here know what Darin Morgan says about the subject ?

thanks.

Originally Posted by adamgl

I had some WCCH stage 2 heads done in late 2009 with Solid Stainless and stock guides. (Before I owned car, I'm guessing around 10,000 miles on that setup) A few months ago I sent them out (again) and got bronze guides, the stock ones had the 'normal' out of spec wear.
So Solid Stainless exh. and stock guides wasn't good on mine. Hope bronze do better.

Originally Posted by '06 Quicksilver Z06

There are 3 descriptions of failed SS valves that I can find on this forum..

1. Madsen, whom is referred to in the above post by Clarksz06

2. 1stZ whom I will familiarize you with in the following text.

3. Corvee, who shows a pic of a bent SS valve with the head snapped off it.

1. Madsen. Broke a stock exhaust valve, running a cam setup, done by an unknown shop, but apparently using stock exhaust valves.

http://forums.corvetteforum.com/c6-z...post1571835806

Following that incident, he alludes to his rebuild following the mishap, in the posts below.

http://forums.corvetteforum.com/c6-z...post1569346169

http://forums.corvetteforum.com/c6-z...post1568963370

http://forums.corvetteforum.com/c6-z...post1568881318

The description of the failure incident a few years later of a rebuild, was made in the following posts The second rebuild was using SS valves.

http://forums.corvetteforum.com/c6-z...-at-strip.html

http://forums.corvetteforum.com/c6-z...the-count.html

The carnage was evaluated here, and a description of what was found, i.e. stock valve guides, was made in the following post.

http://forums.corvetteforum.com/c6-z...#post158479550

The following post indicates that Madsen thought that he was on bronze guides in this particular engine.
http://forums.corvetteforum.com/c6-z...post1584068005

2. 1stZ. Also failed a stock exhaust valve before having his engine rebuilt. After his stock valve failure, he describes his subsequent failure, the rebuild failure, in the following posts.

http://forums.corvetteforum.com/c6-z...-the-road.html

http://forums.corvetteforum.com/c6-z...post1574525676

http://forums.corvetteforum.com/c6-z...post1574483942

From my perusal, and from what I can gather, it appears to me, that both Madsen and 1stZ were customers of the same shop at one time or another. I encourage anyone else interested to look at the posts as well as they may come up with a different assessment.

That said, I can find no mention of the word "bronze" being made by 1stZ when I search his posts. Again, I encourage anyone else to search as well, but I could find no instance.

3. Corvee. Corvee mentions a SS valve failure, and shows a pic of a bent SS valve with the head off of it.

http://forums.corvetteforum.com/c6-z...post1584770192

This also happened in a rebuild following a stock failure.

http://forums.corvetteforum.com/c6-z...post1577078598

http://forums.corvetteforum.com/c6-z...ged-build.html

What I gather from the 3 described failures of SS valves here, is that at least one of the cars referred to above, was said by the person who examined the damaged cylinder head, to be running stock valve guides, which were found to be shot, when the engine was torn down and inspected.

The second car, I could find no information on what valve guides had been used along with it's reported SS valves. Furthermore, a perusal of the owner's posts will indicate that this car was beaten on quite a bit, with multiple 190mph runs, finally failing at 150mph and during a time when the owner knew that the engine needed to be overhauled but admits that he did not have the funds to do so, and kept beating on it anyway.

http://forums.corvetteforum.com/c6-z...post1574525676

http://forums.corvetteforum.com/c6-z...post1574483942



The third car, shows a bent valve, missing it's head, said to have been due to "valve bounce".

Currently, there are 283 members of this forum who say that they are running a heavier than stock exhaust valve, of one material, type, solid or hybrid hollow/solid or another.

What is commonly referred to as; "The Fix", is widely held, among many professional shops as well as enthusiasts, to be the use of solid stemmed stainless steel valves and bronze valve guides.

Originally Posted by Dirty Howie

Very well constructed and researched. A must read for anyone with the same question as the OP.

I just had a GM Corvette Tech at my house assessing my motor after throwing a belt at the track. He agrees the fix is a must for hard driven cars. He actually had to deal with a quide wear warranty and was given special directions by GM corp on how to do the now documented wiggle test. This was several years ago !!!!

Oh, and it was his opinion that the OEM valves did too good a job removing head and the guides can't take it .........


DH

Originally Posted by Dirty Howie

Very well constructed and researched. A must read for anyone with the same question as the OP.

I just had a GM Corvette Tech at my house assessing my motor after throwing a belt at the track. He agrees the fix is a must for hard driven cars. He actually had to deal with a quide wear warranty and was given special directions by GM corp on how to do the now documented wiggle test. This was several years ago !!!!

Oh, and it was his opinion that the OEM valves did too good a job removing head and the guides can't take it .........


DH

Originally Posted by ClarksZ06

Bounce damage within 1500 miles with a comp cam with reasonably gentle lobes. I Highly doubt it. There are many of us here with SS valves with 10-20 times that mileage .

Originally Posted by adamgl

I had some WCCH stage 2 heads done in late 2009 with Solid Stainless and stock guides. (Before I owned car, I'm guessing around 10,000 miles on that setup) A few months ago I sent them out (again) and got bronze guides, the stock ones had the 'normal' out of spec wear.
So Solid Stainless exh. and stock guides wasn't good on mine. Hope bronze do better.

Originally Posted by Vette @ 71

If as some believe, the problem is one of bad geometry (concentricity of valve seat to guide) simply replacing guides will not make the problem go away...Heads that have been re-worked apparently have addressed this problem..?

Originally Posted by Vette @ 71

If as some believe, the problem is one of bad geometry (concentricity of valve seat to guide) simply replacing guides will not make the problem go away...Heads that have been re-worked apparently have addressed this problem..?

Originally Posted by '06 Quicksilver Z06

The thing that is curious to me, and hopefully someone can answer it, is that if the damaged stem that is being discussed is due to valve bounce, then why is it the only one damaged?

Aren't they all the same weight and running the same springs?

Was it only that one valve "bouncing"?

I'm wondering why all 8 of the heavy valves wouldn't have been "bouncing" and ended up with chewed up stems.

Originally Posted by DaOtherOne

DH, I assume you meant removing the "heat" not "head". Did he say switching to bronze guides would handle the heat better?

Originally Posted by ClarksZ06

Extremely Good point but it will not matter.

Originally Posted by adamgl

I had some WCCH stage 2 heads done in late 2009 with Solid Stainless and stock guides. (Before I owned car, I'm guessing around 10,000 miles on that setup) A few months ago I sent them out (again) and got bronze guides, the stock ones had the 'normal' out of spec wear.
So Solid Stainless exh. and stock guides wasn't good on mine. Hope bronze do better.

Originally Posted by ClarksZ06

Extremely Good point but it will not matter.

Originally Posted by Beach Bum

My question if anybody knows..... has any 10,000+ mile plus SS valves with bronze guides combinations been tested at each valve for guide wear via the wiggle test or any other testing ?

Originally Posted by Beach Bum

if they are showing significant wear,

Originally Posted by Beach Bum

then perhaps the problem has not been fixed,

Originally Posted by Beach Bum

btw, anybody here know what Darin Morgan says about the subject ?

Originally Posted by ClarksZ06

I just feel like a few points needed to be made. I'm not interested in talking to a brick wall. I know that doesn't get u very far. So sorry if I opt out of the pointless back and forth with you Mark.
Propain feels differently than I do and that's fine but at least you can have reasonable discussion with him.