LS7 Proactive Valve Remedy

[Da Mammer]

I'm one of the unlucky "5%" then. I was Lucky it was still under warranty, but no such warranty anymore, hope the new engines' heads aren't in that "5%"... I had a noisy valve train and burnt 5+ quarts of oil in 2k miles, and GM powertrain said to try the wiggle test, so obviously GM knows it's an issue with the ls7 heads if that's the first thing to troubleshoot/diagnose...

[OldScoolCamaro]

... the motor has been around for what, 7 years or so? Failures have been well documented. There is an inherent risk with it, as any other line production motor. None more or less with the LS7. But, when it does go....you know what happens. I'd place my bet on it. If I had the Benjamin's...

[Col. Brain]

Originally Posted by OldScoolCamaro

... the motor has been around for what, 7 years or so? Failures have been well documented. There is an inherent risk with it, as any other line production motor. None more or less with the LS7. But, when it does go....you know what happens. I'd place my bet on it. If I had the Benjamin's...

Trick Flow seems to think it is a design flaw in the heads themselves from GM. They have new heads coming out (supposedly this year) that will address this issue.

If I was going to track my Z/28 on a regular basis - id go ahead and order those heads and a cam.

The engines are tanks and wouldnt worry about warranty problems. But if such a case arises - throw the old heads and cam back on

[Mikebrinda]

This matter is outside my field of technical expertise, but I am thinking NASA and the space shuttle. Somehow I don't think NASA space shuttle engineers (and my father-in-law was one working for Rockwell) would accept not knowing for an absolute, scientific, empirical data certainty why an engine drops offline.

Imprinting that same attitude into the minds of the LS7 engineering team members . . . tells me there is more known about this issue than is being acknowledged or released to the public. Engineers are just not comfortable with hope, maybe, might, should, and any other derivative of uncertainty. For an engine design as old as this, somebody inside Chevrolet knows precisely what the issue is.

[mkorgan]

Originally Posted by OldScoolCamaro

... the motor has been around for what, 7 years or so? Failures have been well documented. There is an inherent risk with it, as any other line production motor. None more or less with the LS7. But, when it does go....you know what happens. I'd place my bet on it. If I had the Benjamin's...

So, just to make sure I understand what you are saying...you believe that the LS7 has no higher percentage of failure than any line production motor? I just want to make sure that I did not misinterpret your statement.

[OldScoolCamaro]

Originally Posted by mkorgan

So, just to make sure I understand what you are saying...you believe that the LS7 has no higher percentage of failure than any line production motor? I just want to make sure that I did not misinterpret your statement.

...yes. I don't have the data, but I would think if one drove the LS7 in a normal fashion it wouldn't drop valves for whatever reason it is. I have casually read about it, but have not studied the issue. Hard useage is causing this, along with a material weakness or design flaw. Other line motors diven equally as hard for prolonged periods, or on a regular basis to their limits, will have a failure rate. I for one find this issue still existing to be troubling. As previously mentioned, they know what the flaw is, but the warranty expenditure is acceptable VS the part fix it seems. It must fall within an acceptable failure rate for them not to address it. Being a highly touted hand built motor that is so expensive, and exotic to a degree...it shouldn't be grenading so prolifically or at the rate it is. One would assume it would be stouter and heartier than that. Hollow valves help it twist higher R's it is said, so much for that. Are the valves designed too thin and are structurally weak. Or are the guide tolerances periodically out of wack from the machining process, or is there a dissimilar material wear issue, or is it a geometry issue....???s

[2ss-booya]

I had the same mentality with the oil pump issue on most GM v8's...I figured..hey it's just a rumor...and it's probably less than 5% of sold cars...so what the heck


Then it happened to me...

[kevint]

Originally Posted by Mikebrinda

Engineers are just not comfortable with hope, maybe, might, should, and any other derivative of uncertainty.

We call those "soft" words.

[OldScoolCamaro]

...bottom line is...speed equipment manufacturers. Since the beginning of automotive time, the gap in performance has been filled by aftermarket companies. Build it bigger, better, faster. OEM only takes one part of the way. To go the mile, with rock solid certainty within a reasonable degree...you gotta upgrade. Nothing new there. Like it was said before, the cylinder heads and valvetrain need to be upgraded to maximize performance and reliability with the LS7 or you risk catastrophic results. Stand on it, cross your fingers, and place your bet. If outta warranty.., and it goes south and you suck a valve...thanks for playing Chevy.

[b4z]

It's not just speed equipment manufacturers, but also replacement manufacturers. They will often do a slight redesign or part substitution to a component so that what once was a common failure never, or almost never happens again for the life of the part.

[OldScoolCamaro]

And that is true. It's like the Government versus private industry. One performs a certain function, and one can do it better.

[Col. Brain]

Originally Posted by OldScoolCamaro

And that is true. It's like the Government versus private industry. One performs a certain function, and one can do it better.

Except GM has to stay within certain guidlines (CAFE) and aftermarket can just slap on a sticker that states "for off road use only"

[OldScoolCamaro]

^...and that goes without saying. Furthermore I would like to say you hit the nail on the head exactly. I posted earlier on another thread the belief GM makes a sound baseline motor for much room to grow and expand on power and durability in the aftermarket realm. This has been the case since the Gen 1 engine. From a manufacturers standpoint with all the constraints placed on them, profit margin, regulations, risk versus return,...their hands are tied as to what they can bring to market to consumers who for the most part are only stressing the product to it's limits in a small percentage of ownership.