It knew you weren’t wearing new balances and rejected your ownership

@Motorsportsgeek

Жыл бұрын

He's wearing them in the video so looks like he learned

@shaunwalsh85

Жыл бұрын

Bahahahaha!

@bernardthefourth

Жыл бұрын

LoL! Prob had Nikes on. Get woke blow up.

@scottmason2094

Жыл бұрын

🤣🤣🤣

@MrWashesp

Жыл бұрын

2nd owner things

It’s about $2,500 to $3,000 parts and labor to have this issue fixed before you drop a valve. Every LS7 should have the valves updated.

@ghostwrench2292

Жыл бұрын

Seems like a good excuse to put some performance heads on! 😀

@dennisyoung4631

Жыл бұрын

Treat them as if they have a finite life, and replace them *PREEMPTIVELY?* As in “Lifing” - much like Formula 1 supposedly treats some of their parts…

@zachattack2016

Жыл бұрын

Its the valve guides not the valves

@yungtooli

Жыл бұрын

no thanks. i’ll take my chances.

@hsucduw

Жыл бұрын

They still drop valves even after "fixed heads"

As a retired GM dealer head tech: (ASE Master w/L1 cert.) 40+ years in the buss. and 30+ in a GM dealer I can honestly tell you that GM is the KING at gaslighting!!! Generally when you call about something that will be VERY COSTLY they start to deflect. It's like the old saying: ( If their lips are moving they are lying) Retired 6 yrs now and don't miss one damn thing about dealing with people like that!!!

@epi2045

Жыл бұрын

That’s a really refreshing take from a GM professional. I was in the car business and lost so much money with the GM 3.6L DOHC 24V V6 timing system. This is very surprising about the LS7 pushrod.

@Obshowersyndicate

Жыл бұрын

That's every car maker

@apachebill

Жыл бұрын

Why as a retired 40 year automotive veteran I always printed the recalls/TSBs, and handed my customers the mechanics notes and any photographs before I sent them to the Dealer. I’d tell them to hold back and just ask. The dealer would always blow smoke up their behinds and my customers would hand them the stuff and ask when the car would be ready. Both GM dealers here hate my guts. 🖕’em! My son broke a ring land on a tuned 30k Ecoboost. The tune Ecoboomed the motor. Ford bought him a new one. COMPLETE motor. Gratis! No charge! GM would have said “No warranty due to aftermarket tune” and sent him packing. 💯 %. Ford bought a 25 year old customer for life that day. He’s about to go buy another Coyote Mustang.

@bryany6565

Жыл бұрын

They sure have taking the effort to fix the AFM/DOD lifters too... I have my conspiracy theories that when they took the goverment bailout alot was in that paperwork......

@dicksonfranssen

Жыл бұрын

@larrygreen9100 I really am a team player but it's hard to care when no one else does. Wondering how upper management took the 10 cents ignition spring tragedy, "isn't it time for your break Larry?" We avoided the Takata air bag fiasco by one model year. A new shotgun with every purchase right there in the steering wheel!

It wasn't certain years or a bad batch, every LS7 across all the years is suspect!

@MotivEngineering

Жыл бұрын

I can attest to that.

@ssoffshore5111

Жыл бұрын

@Ralph Depino Yes.

@johncunningham4820

Жыл бұрын

@Ralph Depino . Yeah . A whole new ENGINE is quite inexpensive................................

@spmotorsportsmachine5645

Жыл бұрын

@@johncunningham4820 buddy hes talking about pulling the heads before it happens.....

@trbo355

Жыл бұрын

Agreed!

Greetings from New Zealand. Thanks for the video and condolences on the blown motor. I have an '07 Z06 which I purchased 2 1/2 years ago. Went for a test drive with the then owner and I just had to own the car. At the time it had around 27,000 miles on it and in the interim I did some 'due diligence' on the LS7 head issue and negotiated a better purchase price. I sent the car to a performance engine shop for checking. The 'wiggle' test was hopeless, so made the call.... The Intake valve to valve guide clearance was top limit and the exhaust was 50% OVER top limit. In addition, one of the trunnion (rocker) bearings was in the process of collapsing. Thank god we checked it because the wife would NOT have been happy. Because I'm an 'old fart' of 70, and will never drive this to it's potential, we fitted 1/4" longer valve guides (better valve stem support) and stainless valves. Still have the Titanium valves if the next owner wants to retro fit. All the best with the 'fix'.

@MotivEngineering

Жыл бұрын

Thanks for such a thoughtful comment! You're much wiser than me for getting that all checked out and fixed. Happy driving!

@KelMcBeath

Жыл бұрын

Rob, what part of NZ are you in? I am in Auckland and also have a C6Z06. We should catch up for a coffee.

@user-dn1hp7us7n

11 ай бұрын

@@KelMcBeath Hello Kel. Sorry for the long delay. We live in Waihi and don't get up to Auckland very often in the 'Vette. Would be good to catch up though.

@Ty-gg2sg

6 ай бұрын

​@@KelMcBeath so did you guys meet or what? I'm invested in this budding friendship now 😂

@billybobbob3003

2 ай бұрын

@@MotivEngineering LOL if valve drops such an issue why not just replace the heads with better aftermarket ones to prevent this issue in the first place?

Good to hear that you weren’t inside the cylinder during failure. Always risky hanging out inside the cylinders!

There will not be any contaminates in the oil, these valves fail from the fusion weld of the exhaust valves. The valves in the LS7 are hollow and the actual valve is friction welded to the stem, this is the failure point and there is really no way to predict the failure.

@MotivEngineering

Жыл бұрын

That’s very interesting. I was not educated about how Del West manufactured them.

@sandasturner9529

Жыл бұрын

This is very interesting 🤔🧐 indeed

@blaqlabspodcast5816

Жыл бұрын

Was wondering if anyone was going to bring this up.. Hollow valves are a trade off.. In the past they simply made the valve, then EDM plunge drilled them and filled them with sodium and plug weld the top end.. Gm tried to get fancy and microweld the shaft. Not the best process for this.

@trbo355

Жыл бұрын

I don't think the Del West intakes are hollow or fusion welded. The hollow stem valves are barely strong enough even when hitting the valve seat evenly but throw in a massively worn guide and the poor valve gets side loaded to the extreme, flexes then snaps the head off. It's always the exhaust valve that drops first. I have measured hollow stem exh valves that looked like the stem almost collapsed into an oval with a relatively intact guide. They are junk!

been in a big name OEM and race automotive engine testing lab and the first engine that blew under my watch, blew a rod out the side from a dropped valve was an LS7 back in 2005.

@roberts9785

Жыл бұрын

Was this in building 93?

@marktaylor6038

Жыл бұрын

Bs

@JimBronson

Жыл бұрын

It decided that it needed an inspection port

Vengeance Corvette in Atlanta had a special running that replaced the heads with stage two cnc ported heads with bronze guides and I chose Manley severe duty stainless valves. I think the total bill was about $3500.00. No matter how many miles you have on an engine, get the heads changed out and be done. Anyone who has driven an LS7 would not be happy with an LS3.

@ghostwrench2292

Жыл бұрын

LS3 with a supercharger?

@DingoZed

Жыл бұрын

@@ghostwrench2292 Nope. There's just no replacement for the raw feeling of 7 litres on a lightweight car.

@remissiveslave

Жыл бұрын

​@Yuu Z yeah, they also used this engine in the z/28, that must've been a hell of a lot if fun. No one ever really talks about that car.

@DingoZed

Жыл бұрын

@@remissiveslave hardly no one knows the car even exists if you think about it.

@off-roadnpew2183

Жыл бұрын

@@remissiveslave I never even seen one, I honestly didn’t really know if was in production for that time

As a heavy equipment technician for a fleet with a lot of experience analysing oil analysis I can tell you it is one useful diagnostic tool. I've used many oil sample analyses to solidify a diagnosis or even prevent a failure occurring. But with that not every failure is detectable or preventable even with the best of maintenance. Some defects can create stress points that don't show signs until it is absolutely too late. For an example most Symptoms of EGR cooler failures are detectable with an increase of potassium and sodium in engine oils, but I've seen clean oil samples where the cooler suddenly dumps coolant into the engine hydrolocking it. Data is important, but you seem to forget one thing, variables and endless and can change or even hinder data useless.

@realnikonlover6207

8 ай бұрын

You are 100% right on. Retired now, at one point in my 44 year career, was the fleet manager for an ambulance company. We were running Ford 7.3L turbo diesels. I had the mechanic do oil sampling every 25,000 miles on 22 ambulances. Never had a lot of problems but we did have a brand new 7.3 develop and odd miss and performed the oil sample and discovered a bad cam with infantile failure due to a surface hardening failure. Warrantly replaced the cam and kit including all pushrods, roller rockers and roller lifters. Problem solved no more issues and SAVED an engine.

Hey man, I don’t think you’d see anything in the oil at all before this failure as it’s not a progressive failure. Most likely the valve stem’s non-conformance to the design tolerances caused the valve head to be subjected to a small elastic strain every time it closed as the head was closing on one side of the seat first. This would cause high cycle fatigue in the neck of the valve, causing an almost instantaneous failure as it finally fractures.

@bfelker4144

6 ай бұрын

yes someone gets it

@paulspomer16

6 ай бұрын

Bingo

@87cr250r

4 ай бұрын

In the preview picture, the intake valves look sunken in the combustion chamber. This type of drop can also be caused by recession. This can be detected before failure. There are wear particles but those get blown out the exhaust. Instead, recession can be tracked by measuring valve protrusion. Intake valve recession is often caused by running aftermarket air filters that pass dirt.

From what I learned. The centerline of the guide and the centerline of the valve seat are not in line. A brand new head was measured before being installed, and that is where this conclusion came from. The bare head was a replacement under warranty, and the associated parts were loose. The machine shop had a pristine head to check tolerances and found things out of alignment. 2007 Z06, heads fixed, and Crower shaft rockers installed.

I love the way these ls7’s chop with a big cam at Idle!

If you haven't decided already, I vote stroker ls3 with mild cam. They're great.

This is the first video I've seen of yours and instantly subscribed. My jaw dropped when I saw behind the throttle body.

This is why I went with the c6 grand sport. More or less the same price without the fear of exploding a $15k engine.

@MotivEngineering

Жыл бұрын

I certainly don’t fault you for that decision. The “I’m part of the cool LS7 club” is way less cool when I’m standing at the side of the road waiting for a tow truck.

@Chillin4030

Жыл бұрын

Usually cheaper, more reliable and available engine, and you can modify it for z06 performance relatively easily.

@yungtooli

Жыл бұрын

grand sport aka wide body base model. no thanks.

@midnight347

Жыл бұрын

All you gotta do is put 3-4k into it doing a good heads cam package and you don't gotta worry about dropping a 15k dollar engine lol. And you'd be as fast as many ls3 with boost.

@Sixty6Ninety9Six6

Жыл бұрын

​@yung tooli this is the worst argument for the Grand Sports, considering they have a lot more goodies than just a "wide body"

I currently own a 2015 Z 28 with 35,000 miles on it and have always debated on this issue I’m gonna pull the trigger and get the heads fixed and of course while it’s open upgrade the cam and have headers and high flow cats install the same time I just think it’s peace of mind the car it’s an absolute joy to drive and I love it.

@Waynegs3

8 ай бұрын

I think the at risk range are the 2007-2008 engines

@buddywagner6351

5 ай бұрын

Have you done this yet? I have a 2015 Z as well. I thought this issue was fixed during the Z06 corvette run.

@adamjones7176

Ай бұрын

@@Waynegs3 its EVERY LS7. Do not encourage people to risk a 20k motor on some "I think" statements

Best video I've seen on the LS7 valve drop issue. Pro video quality and editing as well. Subscribed.

Thank you for your video. Very well done. I appreciate your detailed information. I'll be applying the lessons you learned to my car shortly.

Really love how your channel is narrated and documented. As someone that has worked on a few of these cars (c6zs specifically). They are insanely phenomenal cars that respond well to a cam and ported heads. I would do another stock short block or something similar as they are hard to come by and have the heads repaired and ported. BES Racing engines in ST Leon, Indiana has an amazing LS7 program that is world renowned

I'd have to say that I would certainly agree with your reasoning on being comfortable with this engine prior to it's failure. Just goes to show how much of a beating a valve can take when it's in a situation that can lead to failure. I'd put an LS7 back in it, lightly modified in the manner of your choice as compared to what you had.

It's just my theory, but it's based on an experience I had with an early 5.7 V-8 that suffered from valve guide problems at moderately low mileage (60,000 mi.). The LS-7 came equipped with a lot of performance upgrades, with the exception of one thing, roller tipped rockers. GM made the leap to roller camshafts in the late eighties but neglected the one component that enabled the cam to do it's job without causing damage elsewhere. Roller cams have steep or short duration valve opening event ramps, which accelerate the rockers from static to in motion in fractions of a second. It is my opinion based on my experience that this instantaneous motion causes the rocker to not only push the valve stem downward, but additionally, it tends to pull the valve stem up toward the fulcrum of the rocker due to friction between the rocker and stem end. This creates excessive side loading in the guide, causing premature wear and eventual guide failure. In my case, it showed itself by excessive oil consumption via the guides, but with continued use it possibly could have led to catastrophic failure. It eventually led to a complete engine replacement that GM footed the bill for.

@SpecialAgentJamesAki

6 ай бұрын

This makes sense. I couldn’t see play between the stem and guide alone causing this. I have an olds 455 that has some really gnarly play in the guides, enough to hear and I regularly rev it over 6k rpm without letting it warm up sometimes. Not that one engine proves anything but it has roller rockers and haven’t had an issue. So I was thinking if any motor was gonna drop a valve from having play in the stem it would be this one 😆 so I’m on board with the side loading idea.

Sucks to have this happen, but the good news is it gained my sub. Looking forward to seeing how you deal with this unfortunate experience.

This is a relatively exotic engine, materials wise. I wouldn’t expect it to go 100k mi w/o extra maintenance. The valves are Titanium and need to be monitored for elongation. When lash shows the valve has stretched 0.010”, throw them away and put new in. Don’t expect the Titanium con rods to last forever either.

@177SCmaro

Жыл бұрын

Yeah, people don't realize that titanium is a wonderful material - about as light as aluminum and strong as steel - but it doesn't last or wear like steel. Titanium engine parts should be checked and replaced regularly as wear items. I'm told they're more prone to metal fatigue, a bit like aluminum.

@mobius-1503

Жыл бұрын

Damn..

@cyclonebuzz8172

Жыл бұрын

I have seen Japanese motorcycles get 100k on their titanium valves without issues. They are turning 11000-13000 RPMs, but they also are 4 valve motors. They usually are 31 to 33 mm valves also.

@NBSV1

Жыл бұрын

@@cyclonebuzz8172 I’ve seen motorcycles drop a titanium valve at less than 20K miles when just riding along. Kawasaki had a lot of trouble when they first went to titanium valves. I think because they were a two piece valve and the head of the valve would fall off.

@D1vid3By0

Жыл бұрын

​@177SCmaro very true. Titanium didn't have a fatigue limit. It will continously wear until it fails. Just a matter of time.

Got my C6Z06 LS7 with bad bearings and still ongoing rebuild... Lots of headaches about new bearing clearances and parts that are on backorder by GM though... I'm quite interested about the oncoming project of yours and surprised your Oil analysis did not help spot any problem beforehand.

But hey GM says it’s not an issue so your engine is 100% fine

@browningbelgium2326

Жыл бұрын

Just like the experts said about covid shots.

@GamerMomentsToo

Жыл бұрын

@@browningbelgium2326 yup

@josephracicot4443

4 ай бұрын

Lol

As a machinist, you just have to understand the materials, it make perfect sense to why this happened, Titanium has a coating over the material when the coating wears off then Titanium will gaul and stick, so if the valve coating is wearing away, then most likely the Connecting Rod Coating is doing the same, Bronze will not gual Titanium Valves, going to a Stainless Steel Valve or a Bronze Valve Guide will prevent this, Its time to start looking at the connecting rods before you have a major failure.

6K gets you peace of mind. When buying one of these just factor that into the cost and have the valves replaced is my 2cents

@KeithKman

Жыл бұрын

It costs closer to $3,000 parts and labor to replace the valves on a LS7.

@mikec6447

Жыл бұрын

@@KeithKman where you live perhaps. I’ve recently had this work quoted at 3 shops and then performed at RPM in DE

@KeithKman

Жыл бұрын

@@mikec6447 you had it done by the best, I’m sure Fran and crew got you all dialed in.

@lifeonmars03

Жыл бұрын

If I'm buying a fairly low mileage used one from a dealer, you think they'll be willing to lower the price if it has stock heads or they don't care about that? Selling my 14 paxton coyote next week & plan on getting a c6z

@ezmny1387

Жыл бұрын

jesus these shops see you guys coming, valves cost like 600 bucks for a good stainless set.

Brutal and another reason why I got my heads fixed prior to really driving mine. Sub'd to see what you guys end up doing!

@hsucduw

Жыл бұрын

There are plenty of LS7's that still drop valves even after "fixed heads". Be careful

Based on the known probability of occurrence of the failure event described. I suppose a new owner of a used LS7 should simply weigh whether setting a corrected set of heads on the short block, or simply driving it as is.

This is the first of your videos I’ve ever watched. When you inserted the clip about the bird’s gizzard I fckn lost it man😂 had to leave a like

Very well done. Very detailed and cogent arguement.

If you have a LS7, do the upgrades to fix any potential issues. As far as what engine to replace it with depends on what you mainly use the car for. Sounds like you love track. So go with what you is best for you.

@confuse9

5 ай бұрын

The problem is, there is no "THE" upgrades. There are all kinds of theory on why the valves fail. SIde load on the valve, valve material, valve guide material.... No one seems to metion valve springs - but I can tell you a bad valve spring can break a valve (side load placed on valve).

@terrywalker9092

5 ай бұрын

@@confuse9 Agreed. Bad valve springs can cause issues. But the LS 7 is a new animal. It has problems that go beyond valve springs. It's a great and powerful motor, and would to love one! But these motors experience problems way before they should!

We had a c6 zo6 at the shop about a year ago, the way the engine failed seemed to be similar. Total destruction, you could look through one side of the block through the other, it had holes on both sides. The only mods were an intake manifold and exhaust

Well done video. Great information. Good luck to you.

Having a motor let go sucks and I feel for you, but: a Small Block Chevy that makes 500hp and runs for 15 years/70k miles (including track use) is still impressive. Not ideal obviously, but no small feat. I have 30k on my 2007 Z06, stock, bought it a year ago, 4 HPDE days so far. Read all the internet stuff, decided I'm not touching a running motor, fingers crossed. This video is very informative, thank you for posting it.

@MotivEngineering

Жыл бұрын

Adam, I don’t disagree with you at all. You obviously understand my mindset after watching the video. I was nervous to open up something that had been working so well for so long. I certainly hope that you have better luck than I did. Keep an eye on it, I’ll be crossing my fingers for you too! -Mike

@TheTmshuman

Жыл бұрын

A heads and cam package would do wonders for piece of mind. That’s what you tell your old lady anyway. I lost my stock motor to ring butting under boost. Still faster than a lot of cars on only 7 1/2 cylinders though. Shockingly seafoam didn’t bring back my compression🤷‍♂️

@midnight347

Жыл бұрын

I would do a heads cam package it wakes the car up big, sounds badass, and eliminates this issue.

@dietznutz1

Жыл бұрын

Can't agree that it's impressive, 7.0L engine with 500hp, 5.5 mercedes, m113k will do over 500k ? How come all the previous ls engines lasted so much longer ? I would be pissed if my hypothetical corvette blew up at 70k

@Adhoc25

Жыл бұрын

@@dietznutz1 kzread.info/dash/bejne/nol1pJmle9KvpJM.html

It seems to me that you have direct evidence from Blackstone that this wasn't a wear issue. Or at least, the amount of wear that occurred prior to failure was slow and steady enough that it didn't show up as abnormal. This was my biggest fear that prevented me from buying a C6 Z06 - the valve issue is not wear related. It may be a problem with the design where the components can be within the manufacturing specs and still have insufficient strength to stay together over time. Fatigue failure rather than wear failure. And my research indicated that some of the aftermarket fixes might not be reliable either. Failure can happen at any time and there's no perfectly reliable indicator. This is similar to why I sold my GT350. I know some owners never have a problem, but the risk wasn't worth it to me. I would consider an LS3 or some other version of the LS as a replacement to avoid recurrence.

This is a fantastic video. I made one on my channel a while back outlining the issue and offering a clear warning and suggestions. Many people criticized that warning and called me every name in the book except for "logical". I have no interest on rolling the dice...I got mine fixed and made the odds a bit better for my Z06...which I truly love.

@MotivEngineering

8 ай бұрын

I’ll give yours a watch too! Thanks for the nice comment. As to replacing yours early: you obviously are a smarter man than me haha.

“I thought I was safe because I had stock heads and never had a problem yet so I just waited until it became one” 😅😂 OOF. That hurt the wallet.

I've never see more cars blow up at HPDE days than the Z06.

@richardcerritelli9657

Жыл бұрын

Yea with their modified cars this car is hand built with precision the LS7 does not respond well with modifications a totally bone-stock LS7 engine very seldom any problems.

@JimBronson

Жыл бұрын

@@richardcerritelli9657 oh come on man, lots of stock LS7s have come apart. That said, I'd still own one.

@richardcerritelli9657

Жыл бұрын

How do you know they were stock. 2008 through 11 had a small issue and the internet blows it up like they would exaggerate the bottom line when you modify these cars that's when you fall into problems especially the C6 Z06 it's a hand-built specialty engine that does not respond well to modifications.

@gpieschke

Жыл бұрын

True...second most engine track failures is the Ford GT350's. I've personally witnessed 3 of them .....and three C6 Zo6's

@richardcerritelli9657

Жыл бұрын

Because they modify them. The C6 Z06 does not respond well to modifications that engine is hand belt and precision for stock configurations when you listen to the Corvette forum they don't know shit the people think they know it all one person modified their car it blows up and you'd swear a million cars all ZO6 cars have the same problem it's bullshit.

The exhaust valve is a two piece valve and they brake off where they’re fused together.

@slick408

Жыл бұрын

Yeah those hollow ferrea valves are drilled out from solid. I think hollow ss intake and solid ss exhaust is the way to go for reliability. Also roller rockers. TFS has the best flowing small runner aftermarket ls7 heads, add yella terra rockers and hollow intake it will be ready for anything. Mamo motorsports builds on this setup, that's my route.

@MotivEngineering

Жыл бұрын

I'll check that stuff out! Thanks for the advice!

Asked my warranty carrier if they would approve a pre-emptive repair and they said no. They wound up paying a 23,000.00 claim. Then we started with a new 5.3 truck block, installed darton dry sleeves, properly machined and ported LS-7 heads, etc.,etc. Now I have a 440 c.i. beast that is awesome to drive on our local road courses. Many thanks to LME!

At 50K miles I dropped off my ZO6 with Katech in Detroit for a Stage 2 upgrade. I don't track the car, just some spirited street pulls from time to time. I'm at 70K now and my ZO6 is still running great. Fingers crossed the work Katech did while rebuilding the heads will ward off the dreaded valve drop.

I bought a Grand Sport for 2 reasons, 1st was the removable top 2nd was the valve drop issues, I did want a Z06 and almost pulled the trigger on one but honestly the valve drop issues is something I could never be comfortable with driving the car wondering if the damn engine is going to blow up every time I run it hard.

@jwb4bb

Жыл бұрын

Bought the same car, for the same reasons. Gonna be adding AP Radi-cal brakes and a race seat/harness for this upcoming track season, which I'd rather be doing than replacing an engine. Sorry to hear this news, and I wish GM would admit real numbers on these problems, but alas we all seem to get black balled when it's brought up.

@V8dadmartin

Жыл бұрын

We are in the same boat!

@ssoffshore5111

Жыл бұрын

C6Z owner (it's been my daily for years). I knew the risk when I bought it. I considered the GS or a ZR1, but I got a GREAT deal on the C6Z and also had to have that 427! Even if it nuked tomorrow, I wouldn't regret the purchase. With that said, I will be doing aftermarket heads, cam, headers, MSD intake, and TB soon. Partly for piece of mind, but mostly for the additional 175-200hp. I have an LS3 in the car in this avatar and it's a great engine (and handles boost better than the LS7), but the higher revving LS7 with it's larger displacement really has my heart. BTW, does the C6 GS have the aluminum frame like the Z06, or is it steel? What about the CF/balsa floors?

@shaunwalsh85

Жыл бұрын

I could never buy a Z… I want the targa top, and the runflats. The end goal is a built LS7 swap for my c5

@fasteddy

Жыл бұрын

GM has too many engine problems don't know who's to blame and don't care.

Yikes! Definitely rethinking that LS7 swap in the GTO I was planning.

@davidjaime6407

Жыл бұрын

Just get some better after market heads the bottom end is fine

@midnight347

Жыл бұрын

It's so easy to fix just put a good set of heads on it with stainless valves. Heads cam should be the first thing any ls7 owner does. Why not? You make the car sound wicked and run way better and eliminate this issue all at the same time.

@new71owner

Жыл бұрын

​@@midnight347 only thing is, stainless valves weigh more, and valve float is a very bad thing. Make sure you have the proper springs to control those heavier valves. Or go sodium filled very pricey

@midnight347

Жыл бұрын

@new71owner yea this is true. It can be remedied just gotta do your homework.

I'm actually quite curious about this. The Z06 has Massachusetts plates, but in the video you mentioned being in Kansas? Did you move or was it originally registered out east? Super curious only because I live in RI - that's how I recognized the Mass plates so easily.

Coyote swap 😂 sorry I’m a Ford guy and I had to do it. The first motor I ever blew up was a “built” 3 valve that was pro charged after a month of ownership. It lasted 4 years and after I tore it apart I found out the shop that “built” the engine just pocketed my money and threw trash parts into my engine. Lesson learned 👍

You could always check the valves by taking the valve covers off and wiggling the valves. Also its super easy to just get new valve guides installed. Also its shitty how GM never truly took care of this issue in their best corvette ever made.

There are many factors to consider in any part failure . This is one heck of an expensive failure to have gone on this long !

The LS7 was also noted for breaking valve springs, which allowed the valve to contact the piston. My neighbour's '06 developed a miss, luckily at slow speed a couple of blocks from home. Fortunately, the spring still kept the valve away from the piston. I replaced the broken spring with the head on the engine after a leakdown test verified the valve wasn't bent and it has worked fine for 5 years now. I did recommend replacing all of the springs, but he is cheap. lol

Mine had connecting rods rubbing. Found that with an oil sample and then an in-depth look at the oil filter media. My car had the heads “fixed” by lingenfelter when I bought it. I asked the shop to check the heads while the engine was out. Valve guide to stem wear was excessive. Lingenfelter will not stand behind their work nor would I trust them to “fix” their mistake anyway. The exhaust valve seats were already leaking too. Heads are being sent to AI in charlotte NC. Block is being fitted with Eagle forged crank, K1 conn rods, Carrillo pistons BTR stage 3 cam, new lifters, trays, &pushrods. Doing the CHE trunion upgrade to the rocker arms, Manley stainless steel exhaust valves, AI bronze guides (maybe new intake valves too). Kooks 1 7/8, 3”x pipe and McLeod clutch with bleeder. That oughtta fix it lol

@spmotorsportsmachine5645

Жыл бұрын

put a set of TSP roller rockers or else you will be in the same boat with worn guides..... again

My Corvette specialist said if you're at nearly 50k miles, your chances are lower, but not 0%. They said if you plan to track the car, you should do the heads anyway.

@browningbelgium2326

Жыл бұрын

Good advice!!

After much ado, I couldn't do it, and bought a 13 LS3 GS. I can supercharge it. I wanted the steel frame.

@MotivEngineering

Жыл бұрын

And you’ll have many trouble free miles ahead. Enjoy!

@MasterCarguy44-pk2dq

6 ай бұрын

LS3's can't handle more ghan 625 wheel if longevity and reliability is your brew of taste. I know many guys on their 2nd and 3rd LS3, supercharged and right around 615 -630 wheel. None of them have a gm V8 anymore.

GMs had the wiggle test for YEARS in the 80s/90s it was common for GM calling for "wiggle test" while diagnosing electrical problems , wiggling the entire harness from from to back to see if a fault spike occurs.

Excellent information!

My c6z got 85k miles on the clock, the oil sample looks clean and I was thinking the same... If it will drop it should have already been dropped.😢 Damn now I'll get my h/c done sooner

@klausschreyer7062

Жыл бұрын

Oil sample not going to tell you about Valve Guide or seat issue

GM....designing things to fail for service revenue is our business model. Have a nice day.

@rome525

Жыл бұрын

Planned obsolescence is a real thing the big three put in.

@phantommedia9964

Жыл бұрын

Do you work for GM?

Thanks for sharing. I owned a C6Z for a couple years. I miss how special that car was, but not the interior. With the valve issue, driving that car was like dating a stripper. Amazing and insane, but in the back of your mind you always had to be aware it could go very wrong, without warning, at any time.

I always used to hear Gwatney Chevrolet radio ads when living in central Arkansas. They are both in Jacksonville…surely must be related

Nothing like dropping a valve for engine destruction!

Would stainless valves live longer? Probably but you gain valve float & rpm

@bradgriffith4231

8 ай бұрын

Short answer is NO! IF SS would take the heat & abuse the Ti valves withstand, all serious race engines would run them because they cost 1/10 the price of Ti valves. Weight is another consideration. The lighter the valve train(including lifters, pushrods, rocker arms, valves & retainers), the less the valve spring pressure required to control it. 10,500 RPM NHRA Pro Stock engines run 600+lb SEAT PRESSURE & crazy high open pressure to control big titanium valves without issue. The current method used in race engines of adjusting "installed spring height" is using the peak lift spring pressure rather than seat pressure.

I wish I had seen this video earlier. Mercury Marine makes a dual overhead cam version of the LS7 that revs out to 7500 and makes great power.

Thanks for keeping it real 💯

Yo why is this engineer so damn jacked? Asking for a friend

Had this happen 2 years ago after a cam upgrade, the car ran fantastic at the dyno, after i got home and took it back out. Around 2nd or 3rd gear spirited run it just did a quick pop and smoke from the engine. About 8months later, new build : ls3 block bored out with darton sleeves, larger forged pistons, step up larger bore, replaced the one broken titanium rod, everything was fine, kept all the ls7 components ( rotating assembly etc). New set of stock ls7 heads got the entire vlave job completed, kept the titanium valves, upgraded the exhaust to ferrea ss. Tsp stage 2 cam Rocker bushing upgrades Msd intake.manifold Nick Williams TB Basically all bolt ons with extra major internal upgrades, ran 630whp at the dyno and revs to about 7500rpm. Next upgrade will be Vengeance Performance head work, upgrade fuel injectors, and id say gra few extra HP with harmonic balancer and a ported msd intake manifold. I should be able to get this monster to 670whp NA on 91 octane At the most maybe ij the future a procharger running 3lbs for thst extra 50-80hp lol not sure i can get anymore power NA after the heads / msd porting

@MotivEngineering

8 ай бұрын

Holy crap you’re building a monster haha. That’s awesome to hear, good luck with it!

@avgeeks5638

8 ай бұрын

@@MotivEngineering ya no doubt.. Although chasing electrical Gremlin now

Sorry about your engine...Really sucks....Great no-nonsense video though on the issue. For years I've heard so many conflicting stories on the problem on the LS7, you explained it clear and concise. I have a C5 Z06 (LS6) with similar mileage and it has very bad piston slap when cold, I just live with it. I haven't heard of any valve drop issues with those but now I'm worried.

@ForgottenMuscle67

Жыл бұрын

Ls1s don't have valve drop issues however if you have a ticking noise, check your rocker arms, they are notorious for losing their retainers and dropping needle bearings causing the rocker arm to lean and giving a piston slap sound, happened to me

@StupidFastTruck

Жыл бұрын

@@ForgottenMuscle67 thanks...I'll check that out!

@browningbelgium2326

Жыл бұрын

Valve springs on the LS6 was the biggest topic I heard about and some concerns about the water pumps going out before it was time to. Other than that, LS6's are bullet proof. I think FluffyGear hit it right about your problem.

@ssoffshore5111

Жыл бұрын

If your C5Z is a 2001, they are known for the cold start piston slap. If 2002-2004 (they fixed that issue), I would suggest tearing it down before you have a more serious issue.

Put a Coyote 5.2 Voodoo in it.

make it an electric track car or a coyote swap! Or stuff the c4 ZR1 into it

I bought a 8,500 mile Z and the first thing I did was fix the problem via Lingenfelter performance. If you buy the car understand this is not an option. And honestly it’s a great first mod. Gives you a chance to upgrade the valve train , new head gaskets and CNC port the heads. My car makes 531 with no cam , just fixed heads and intake.

I have a 12K LS7 and I'm terrified of what happened to you. I literally have one of the first sold 06 Z06 engines. I don't intend to ever beat on this at all but still keeps me up at night. Peace.

If you have an ls7 car don’t risk it you have a couple options you can send the heads out for a professional valve job, or buy an aftermarket set cnc ported heads, you could also send your heads to Texas speed or other head porting services to get a cnc port job and a good valve job, ls7 will make 70-100 hp more with just ported heads and a cam

*Exact* same thing happened to me, except (LOL) it was a 1966 VW Type 3 Fastback with the 1.6L flat four air cooled engine. #3 Exhaust valve broke off and was munched. Cost me about $400 to have fixed by a local garage. Replaced one bent connecting rod, smashed up piston, and head; all good used parts. Same engine was later involved in an engine fire, destroying the car and merely damaging the engine. Same engine later caused a 1957 Beetle to pull a one-foot high wheelie, so there is that.

I have an 06 GTO LS2,I hear light clicking low rpm's always have,what about the heads on this motor,strong as a horse running wise,do tell?great info on LS7 thanks for video

Is there a certain year that this problem was taken care of? I’m in market for a c6 zo6, didn’t know if I should look for 2009 and up or only 2013 or..?

Excellent video

Great video!!

how could you see something about valves or guides in the oil since the giudes are underneath a valve stem seal, so it doesn't see oil

Sorry for the loss. Quick question. What does the valve spring look like? Is it broken or bent with the valve??

@MotivEngineering

5 ай бұрын

We’re showing all that and more on an upcoming video. Planning a full engineering deep dive and analysis to what happened on this motor.

Fantastic video thank you

So sorry, saw your post on the forum. FWIW, I bought my Z06 with only 6k miles…and the AHP pkg 4 heads actually arrived a day before my car arrived. Just sayin. Turned out several valves were at, or slightly outside GM spec (and way outside AHP spec). Would it have held? How long? Who knows? Too expensive to chance it. And yes…chance of failure obviously increases exponentially with aftermarket cams. Heck…the engine already has 1.8:1 rocker ratio. I’ll also add that with such oil temps, I use heavier oil, moreover with much higher ZDDP for added lubricity. And try to keep oil under 250f (long story). Again, sorry for your failure. I’d source another LS7 (stock cam!) and make sure the heads are refurbished. Good luck…and great video

Great information, keep it up

As a huge vette fan and owner (C5), I had no idea this was even an issue. I feel like if i was in your shoes, i'd replace the engine with a destroked ls7 build. I've always wanted to have an ls2 or ls7 with a forged 4.8 crank in it for the high rev range. I feel like it would be huge fun, just remember to change the valves ;). Its unfortunate this happened though, good luck with whatever you replace the ls7 with.

@bradgriffith4231

8 ай бұрын

The stroke doesn't have anything to do with high rev potential. RPM limit is controlled by the size of your wallet & the quality of the valve springs, valve train components & othe reciprocating. My buddy turned his 555BBC 7500+ & ran it 13 seasons in his 7.97 second/168mph Super Comp 86 Olds Cutlas. He is now turning his 440ci Small Block Olds 8500+! 500ci NHRA Pro Stock engines are chipped at 10,500 & were turning 11,500 before the RPM rule & NASCAR was turning them over 10,000 before the gear rule to lower the RPM to help lower costs because they were changing valve springs 3 times per weekend at a cost of $3,000 per set. Pro Stock springs have higher seat pressures than most valve springs ever see at peak lift.

Just subscribed, glad you made this video

@MotivEngineering

8 ай бұрын

Thanks for the sub!

Do you think it wouldve ever happened with tvt green or a similar additive?

great video!

Never heard of this issue before now, would probably just chock it up to the amount of WOT it likely saw in its life. Thanks for the video 👍

@Lunch-b0x

6 ай бұрын

It's a performance sports car, arguably a super car. It's meant to see track use, and WOT. GM fucked up, end of story.

@TheCanadianBubba

6 ай бұрын

You sound pretty heated about it, did you lose one like this too ?

@nishimiya

6 ай бұрын

cant tell if you're stupid or just candian, well i mean both goes hand and hand so theres that lol@@TheCanadianBubba

wanted to mention this a nice video production good quality and entertaining.

It’s all okay in the long run. Lots of money will make it just like new again, or even better!

This is where good quality machine work is worth it’s weight in gold, but good chance valve spring fatigue/lack of spring rate is the cause of this, and most certainly not oil contamination

Curious if it was lean, heated the valve, valves stretched and kissed piston

Valve failure will never show up in the oil. I’m pretty positive the ls7 have hollow stemmed valves. They are super light weight, but in return they tend to be brittle and unable to stretch, so there is no wear evidence, they just snap eventually.

I know that the 1961 - 66 Buick Nailhead had side loading issues with the valves. Replacing the rocker assembly with the 53 - 60 version fixes that problem and the problem of dimpled valve stem ends as well.

@thegarynator

Жыл бұрын

That's good to know, I'll have to keep this in mind for when I restore my 66 Electra 225. Thanks!

Sucks to watch about your issue! Did you have an expanded oil tank installed? Lot's of info online about oil pressure drop when on track with long sustained (over 2 second) high g corners. Just curious if you ever logged Oil pressure (looked at your videos but you normally had oil temp on the screen). I'll be tracking mine this summer... Looking forward to any rebuild videos!

@MotivEngineering

Жыл бұрын

Thanks for the comment! I only had what came from the car factory via oiling (8 quart dry sump). I never logged oil pressures, always kept an eye on them, but never wrote anything down. They always seem to be in the “normal” range (20-80psi, depending on conditions). I’m always on the quest for knowledge for contributing factors that caused the LS7 failure. If you’ve notice anything from mine or yours, definitely let me know!

Gm recommends 15w-50 for hard driving/track use. I wonder if this is why, to help prevent valve drop issues.

I want to know more about that massive crankshaft that is featured at the end of the video. Please share some details.

I’m kind of new to this. Been wanting this car since hs. Now that I’m 31yrs I’m finally in a position to save up a buy one. Is this like some sort of “must fix” deal or you’ll end up blowing the engine?? And back in middle school I heard these engines were hand built

I had a GM service bulletin on the 6.2 heads cracking and just upgraded the heads to prevent problems. Any time you have a service bulletin, replace or fix item regardless.

Wow you are one smart dude. I am very proud of you

You mentioned that you're in Kansas and I'm looking for a reputable tuner to take my G8 GT to around the Johnson County area, do you know of any shops you trust?

@MotivEngineering

Жыл бұрын

Only shop I’m familiar with out there (I was in Manhattan) was White Owl. I have zero experience with them and don’t know anyone personally whose done anything with them. Sorry I can’t be more helpful, but if you’re looking for somewhere to get started you could give them a call?

So is a 6.2 iron block with ls3 heads better than a 7.0l ls7? Thank you in advance