Matt Cyber Z06

...That Most All people Rebel against what Katech is saying about the Valve Guide issue ? Just spoke to Jason (for the second time) and it is Not on the same page as to what Most are calling a Fix.

Do we really think there is a conspiracy that GM and Katech is teaming up to Fraud/Lie the LS7 Crowd ?

Turbotank

What did he say was the problem then?

Lawdogg

Whether it is heat, guide material, two piece exhaust valves, guides that aren't long enough, geometry, etc., people have so far had good luck with a one piece ss exhaust valve with longer guides. Might be what an engineer would call a bandaid fix, but if it works, then so what if it is a bandaid.

Painrace

Andy Pilgrim's comments,

"That’s Jim Painter’s beast of a car. He let me run it and take someone around the track as a ride along, pretty brave of him really. Tell you what, that thing is very, very quick and the suspension is sorted, plus Hoosier A6s and you are cookin…. Cheers"

Katech engine and many other Katech modifications. Stock valves!

Jim

tail_lights

erichg1000

Then John Ingram said

"I'm not really sure why they call in barbacoa. It's like a mescin bbq I guess. One thing I know is you eat that up with a piece of fried corn and the dogs come a runnin'! Couple two or three times I've cooked up a dish for my family that the dogs liked. I like lamps"

propain

The problem has pretty much been proven that this is no more than a machining issue coming out of GM's head supplier.

All the other "fixes" are more than likely unnecessary. Do they "work", Sure. Have they been proven to have any kind of longevity, no. Were they done during a time when people had no idea what the problem was or why it was happening, yes.

JWingo

EX1

Like propain said, It has been a proven machining issue in the heads. I still believe that switching to longer guides help reduce the side load the valves experience too.

Lawdogg

When was the machining issue proven? Haven't exhaust valves broken in all years that the LS7 was produced?

rockinSeat

Because, it's hard to believe that after 50+ years of making V8's, GM would have such a widespread machining flaw - but from what I understand of Hib's article, the LS7 used the first mass-produced heads that are CNC'd. It may as well have been GM's first year of building them. And I did see an article that Linamar is growing so fast that they can't find enough skilled machinists to hire - if anyone can relate to that situation.

Someone posted earlier that when their local machine shop was assembling his new warranty-replacement heads, the shop verified they were already out of spec and had to correct the issue. So that's one piece of evidence that a machining defect definitely exists.

My humble belief is that a moderate to high percentage of of 06 - 11 cars had the bad heads slapped on at the factory. By MY 2012, heads going on new cars were being inspected, but even today there are still bad replacement heads and catalog-order heads in circulation. I guess GM expects the machine shops to fix everything.

So I do believe it was a machining issue, but I don't hold anything against the owners who have gone the SS/bronze route.

caker

That's a really sweet car you got their Mr painrace sir. You the master.

propain

Intakes also coming back out of spec with the exhausts still being in spec. This rules out the heat problem as well. Heads with hundreds of miles not thousands inspected and being out of spec. You simply cannot ignore all this evidence any more.

I have nothing against the owners who have gone SS/Bronze either. The decision was made during a time when we had no clue as to why the problem existed. In light of all the new evidence the thought process of what needs to be done and the reasons for doing it should now be thoroughly considered.

Matt Cyber Z06

Same thing that GM said. Machine issue that was resolved.

When I told Jason that GM replaced My heads with Full new assemblies, He seemed kind of Dum founded that I wanted to Go any further with my Street car.

There is more info he states as well But most know this already--
They use Stock PM guides and Stock Intake/Exhaust Valves on there
builds and warranty them.

I just don't understand why they don't have more Credibility and trust on this forum ? Seems like if we hear One 2011 failed, They all are Infected

propain

They have plenty of credibility and trust on this forum. There were a select few who made it their mission to poison the forum against Katech. Nothing more.

Katech is the big boy on the block. Everybody wants to take a shot at the big kid. Its all about business.

forg0tmypen

I agree. Good post.

The_Raging_Bull

Katech engineering contributed to the LS7 design, and I agree is the big guy on the block. If they were building faulty engines (air attack, street attack) you can bet there would be folks talking about the issues they had with a Katech build. That said, perhaps their success with the stock PM guides and stock intake/exhaust valves in their builds is due to they are doing a better job than GM. The comment around CNC'd heads is on point.

To their defense, I personally think a Katech engine is the gold standard for NA LS7's.

Matt Cyber Z06

Ok,

Well Katech says: (in short) a Heavier valvetrain is no good
and has shown Negative affects on there "Spintron"

Does anyone else have a Spintron ?

They Do Not recommend SS Valves at all

Dirty Howie

Just dropped in to check out the cool aid party



DH

'06 Quicksilver Z06

When a forecast of bad things to come should one go in a specific direction, doesn't quite pan out, doesn't come to fruition, and bad things don't happen, then just what you seem to be observing, is going to happen.

You end up with a situation not much unlike that of the boy who cried "Wolf". After awhile, when no wolf shows up, people ignore the cries of "wolf" and go on about their business.

Since that Spintron report came out, somewhere around 40 members in here have gone ahead with SS valves and bronze guides as a means of managing the issue frequently discussed in this forum.

Forum vendors are going on about their business, doing the same thing that they have been doing for years, and have one satisfied customer after another.

Recently, a group of 4 forum members in here have elected to go this route, despite what you allude to above.
http://forums.corvetteforum.com/c6-z...m-install.html

Disaster has not been rampant amongst those owners or shops, despite the position you reference.

Also, it's probably not surprising that when engine failures do crop up in any automobile manufacturer's flagship engines, then any other companies which have had a real or perceived working relationship with that auto manufacturer, past or ongoing, or made any contribution to the development of those engines, significant or otherwise, well again, you are probably going to observe just what you are observing.

When there is a warning of disaster or bad things to come, well then they had better show up.

It's just like the weatherman who predicts rain, but each time he does, it's bright and sunny not only the next day, but for the next several days. It's human nature. After awhile who is going to listen to his forecasts no matter how fancy his equipment is?