The Truth about the LS7

Thanks for the info , it gives a potential buyer something to think about.. negative comments usually come from hot Rod enthusiasts..anytime you street race or just hot Rod an engine there’s a possibility of doing some kind of damage that can rear its ugly head later on.. I have a 2006 C6 LS2 coupe ,in the garage , I bought new. 34,000 original miles, have not abused this car.. I plan on taking it to Lyle one day for work ( balancer) that’s been needed so I can get it back on the road.. even though it’s a stock 400hp engine there’s plenty of power to enjoy.. thx Lyle

Bronze guides, roller rockers, and methanol/water injection, you can run it leaner and meaner without the heat buildup in the cylinder head, upper block, deck mating surfaces, pulls the heat off of the exhaust valves chamber surfaces and piston crowns, and not only flushes large portion of the generated heat out of the exhaust, it consolidates the heat and exhaust gasses, puts less of a workload on the catalytic converters, letting the exhaust flow better because it has more mass per pulse, it improves the cylinder scavenging. It reduces the intake charge temperature, increases the density, and velocity, rapidly absorbs residual heat and vaporizes and enhances fuel atomization, more fuel is ignited and completely burned. Less concentrated heat in an isolated area (inner exhaust port) valve guides and stems don’t reach critically high temps, and the thermal cycling expansion and contraction are minimized, ceramic coatings on pistons cylinder head and valve faces (combustion chamber surfaces) for thermal barrier and lubrication augmentation. Roller rockers and improved valve train geometry can be achieved but that’s a lot to post.

Another thing the Tech Nerd from Corvette Magazine has said is that if the engine is going to fail it will do so early in its life. I cannot recall the mileage but want to say 10k miles.

Very informative,Don't have a LS7,LM7 here,But knowledge is King,Thank You.

My 08 Ls7 with 11k miles had valves out of spec with play. Dont believe the BS! Get your heads done!

Regardless of what anyone says,he is exactly right

I have a 09 C6Z and have tracked it since I got it. A track friend had one too and while running at Sebring with NCM he dropped a valve on the back straight. His was stock. Luckily, there were GM Engineers there and jumped on the car and had new heads delivered to the local Chevy dealer the next day and all was good. My engine, after my 2nd trip to Daytona, a distinct “ticking” was heard. It was under an extended warranty so my local dealer swapped heads for me.

so basically he is saying GM made an engine that revs 7000rpm but dont do it as you will break it

I own a 2013 427 convertible with 44k miles (stock drivetrain). The car is not driven hard at all and while stopped at traffic light the valve spring on the #8 cylinder decided to take a walk. Towed to the dealership and the service manager says, oh, your car may be one that is noted for valve issues. Two days later I am told the intake and all gaskets warped and need to be replaced and GM will not help defray any of the costs... You would think GM would have stepped up and at least offered something to support a loyal customer who spends a tone of money for their product.

Junk 😂

Had a 7.0 bone stock 2009 from brand new, and it eat a value, oil change ,rocker adjustment, and it was a lash check ,even the coolant, all under 30000, and boom exhaust valve gone. Had a machine shope build one , and man it still runs today ,got power to five grand, big cam opened up the heads. Gmail made them last past the warranty and after that blow on the dice and hope for seven or eleven.

You have no idea what you’re talking about first, second, if you’re gonna literally sit there and insinuate that putting a cold air kit and long tubes on a car can damage the engine, you need to put the pipe down.

If it’s damaged afterwards, it’s probably not the cold air kit or long tubes fault.

Who the hell buys a z06 and keeps it stock smh

The LS7 was the perfect storm for valve wear, the 1:8-1 rocker ratio, 7000 rpm redline, offset rockers and sodium filled valve stems that added heat to the valve guide cooking the oil to a grainy slurry, plus the decision to not use the titanium valve mfgs. proprietary coating which caused the rough titanium surface to erode guides. I had a 09 with 34,000 miles stock and the valves had 13,000th slop..Yeah nothing to see here.......

I’ve had two LS7 engines (C6 Z06 and 5th Gen Camaro Z28) and without hesitation I will admit that the LS3 engine is better than the LS7 for tuning and longevity and reliability.
LS3 is the best V8 GM has ever made in my personal opinion

So basically the LS7 is maxed out from factory, and u can't do jack to it, so basically it's JUNK. Unless u keep it stock.

C5 zo6 > z6 zo6 so what you get an extra 100 hp but it’s not nearly as reliable as the 5.7

I would buy one with a LS3. Then do some bolt on . Can achieve LS7 power with a lot more reliability and probably less overall cost than a C6 Z06. 😮

Disappointed. This video was made for mechanical ignorant. There was lots of generic talks and nothing about LS7 specific cause of failures. From what I have heard failures has happened in all year LS7 ZO6s with stock engine. Of course, GM chief engineer and CEO would not admit to any problems. Talking to them is waste of time. Because of this, I am looking for a C7 Z06 even though C6 has much better styling.

I WANNA SEE YOU TALK ABOUT C7

is ls7 tops good for a ls3 bottom ?

What a load of BS.

Delicate LS7. No thxs. It’s not if, it’s when are the stick heads going to fail.

Sooo don’t buy Cletus Ruby😢

You’ve been misinformed by your GM buddy.. There must be a record of over 10k engine failures in the LS7. When the exhaust valves were designed and welded there were flaws that allowed the valve to break at the weld and destroy the engine. It happened to owner racing their cars and some simply driving normally. GM knew this and hid the fact that any LS7 could grenade at any moment. GM simply hoped owners would make it pass the warranty. Thousands got screwed bad on these cars. Some were smart enough to replace the GM heads with aftermarket units that basically saved the owners from 15k dollar repairs. Making excuses for GM isn’t a good look

This is such a bummer for me. The base v8 Camaros and corvettes just don’t feel special enough to me. Supercharged is alright but honestly and Cars like this it seems like too much of a good thing. You just spin the tires. The zo6 and z28 are the sweet spot with naturally aspirated and have the special feeling but then have all these issues with the ls7 and that’s why I won’t buy one. Really a bummer to me. I mean gm has got to be a multi billion dollar company and they can’t build a reliable 500 hp v8. They knew about the issues in 06 and basically did nothing to fix it for almost 8 years or whatever. I’ve considered buying a low mileage stock one and have some work done to “fix” the problem. But then your probably another 5k$ more into an already expensive car and I don’t know that even with the “fix” I would feel good about driving the car hard. Really a bummer for me. But what can I do

Great info thank you!

Asking GM if they have an issue.... I knew the answer without watching.

I’ve got the ls2 but I’m going to swap out everything. Custom motor, torque tube, transmission, and diff. I’m trying to reach 1,600 hp

I have a 2006 Z06 with 101,000 miles on it. I shift at 5800-6000. The engine has so much torque that there is no reason to rev past that. (only has had oil changes--still has the factor spark plugs-new clutch at 98,000)

Thank you dad

So basically GM designed absolutely no headroom for modifying the LS7 (as in more airflow and fuel = more power)? Why would they build something so fragile or made of glass like that? You would think that the Corvette being a potential track car would be over engineered to be able to handle modification and abuse. Most German and Japanese cars in my experience are so over engineered you can mod them way over the factory spec and they hold together just fine as long as you run the proper oil and fuel. How disappointing as the Z06/C6 is the only newer Corvette that I like style wise and would buy.

Part of the problem is these engines were made to run WAY TOO HOT in order to comply with the stupid government rules for emissions. The more heat that stays in the engine = the more problems.

Wouldn't it be nice if we had ACTUAL STATISTICS on LS7 valve drop failures.

These comments about changing the exhaust or installing a “cold air intake” are nonsense. They will not lean out the air/fuel ratio. If the engine flows more air (which an aftermarket exhaust and a CAI aren’t going to change the airflow much), the MAF sensor will see the increase and the PCM will add fuel to keep the AFR where it’s programmed to be. The only way you will lean out the AFR is by tuning the PCM to be leaner, or making extreme changes that the fuel system can’t keep up with; like adding a supercharger for example.

another great video

Great engine with the right cubic inches, BUT, it should’ve been issued a recall for the head issue. To add insult to injury, Chevy had the arrogance to install it in the Z28 with the same junk heads on it.

117,000 miles on mine so far. Bone stock engine. Even the air filter is the stock AC Delco Donaldson Power Core. Was very diligent during break in period, swapped the oil/filter at 1100 miles. LS7 continues to be a gem of an engine for me. A very interesting article in Corvette Action Center by Hib Hiberson "The Ruthless Pursuit of Power' states (if I'm remembering correctly) Feb 2011, GM asked or required Linimar Manufacturing (they machined the heads) to do a 100% inspection on them instead of spot inspections. And the valve guide issue was largely 2008-2010. My engine was built in 2012 for the 2013 model year.

I modified my car and it broke... GM is to blame... REEEEEE

american heritage and katech did a lot of work on these heads over 10 years ago. while it's more likely they fail under mods or repeated hard use some have failed bone stock. that coating GM used on the ti valves was sometimes not done as well as it could have been, this coupled with out of spec guides or uncoated valves wearing on loose guides and then grenading themselves is mostly what's behind this urban legend. for $3500 ahp will completely rebuild the heads with new PM guides, new much better ti / moly intake valves and hollow ss or new stock exhaust valves. for $600 more you can even run F1 guides. the cost of the ls7 is so high to replace i could not imagine having a c6z without factoring in $3500 for the cylinder heads the day i took ownership. it's like the stock valve springs on the c5z, moderate deal on the 01, major problem on 02-03 and less of an issue on 04 but worth changing if you go racing even on the 04. if a valve does go through the piston on the ls7 there's at least a 50/50 chance it also takes out the block and that means. realistically you're spending 10-15k for a used motor or 20k+ for a new / built

Excuses for something that was built on the margins in too many aspects...
Sounds like your income relies on good relations with GM...

What about valve guide concentricity? Is the GM tech unbiased?

I was wondering why is all that space technology for on the LS7? titanium, sodium filled valves, special valve guides, etc, etc. Turns out that you shouldn’t rev the engine, you shouldn’t change the muffler, you shouldn’t do anything with your car! I built an LM7 5.3 from a truck everything stock but the camshaft and valve springs, I rev it to 7000rpm any time and nothing happens

I'm going to purchase a C5 Z06 that has aftermarket headers. My question is will the aftermarket headers damage the engine because they aren't original equipment?

The valve seperates itself from the stem and this detroys the engine completely when that happens. I just saw one yesterday BONE STOCK ENGINE valve missing. Engine seized pulled the head off and piston is gone rod and wristpin destroyed the cylinder crscked the alloy block behind the sleeve inside a coolant gallery.
The engine is scrap. She is fucked. To say a cold air intake is responsible for a valve breaking from the stem. Come on dude.
People are not stupid. And telling people dont rev them to 7000rpm.
Then Chevy should have limited them to 5500 rpm not 7K if the revs are the problem. Problem is the valve guide. The valve touching one spot when it closes on an angle for so long and bam breaks off. Its not rocket science.

So LS2 engine is better than the LS7?

And there we go again. subscribe and a like within the first 5 minutes.see ya.

I got a c6 z already canned and ported heads to avoid any issues not to mention it can beat or at least run next to a c7 z. 566 to the wheels which is what c7 put out
And the answer is a c6 z is rolling the dice with out new heads.

I've had my C6Z For 12 years on stock untouched heads one of my favorite comments in a forum on the subject was a guy saying wow mine has a 150,000 miles on it. I'd better check my clearances...

A racing engineer much smarter than me, once said 95% of engine wear comes from the last 500rpm of the redline.