I saw your video before I bought my 06 Z06. My ignorant ass thought all folks out there including you were just over-reacting. I bought my Z06 about a month ago and I took my chances. Few days ago, my LS7 dropped a valve and blew up. Now I'm facing 16.5k repair bill just for the new crate engine and labor (I gotta get it fixed whether or not I want to keep the car). The issue is damn real guys and it is terrifying. Get your heads fixed if you haven't already done so, unless you want to put yourself into a big financial trouble. Even the new crate LS7s have valve guide issue and I must get them fixed before the 2-year warranty expires. Don't be an idiot like me and get your heads fixed for God's sake. Thanks for the good video Jason.
WOW...I am SO sorry to hear that. A lot of people say that it is overblown and a non-issue, yet I her about these things all the time still. Again, I am sorry that happened. Check with AHP...they just released their own engines and oh boy...do they look good.
@@InJasonsGarage I couldn't afford AHP's LS7 with pre-fixed heads (go for $14.4k +shipping & tax) so I got cheapest LS7 crate with chevy performance 2-yr warranty. I want to get the heads done ASAP regardless of warranty period. I just don't want to worry about valve drop when I'm driving. This is such a pain in the ass if you are not prepared for near $20k repairs. Hope people out there realize how terrifying the issue is and get their heads fixed... No more LS7 needs to blow up due to owner's ignorance.
So the "new" LS7 crate issue ship with the defect also? GM refuse to correct the problem, even on the replacement engine? Wanted to make sure I read that correctly, seems very strange.
Valve guide wear should be checked every 20k at minimum even after the repair has been made. The high redline in the ls7 causes valve motion that wears valve guides out even if the guides have the right valve guide to valve stem clearance and even if the guide machining is concentric.
Great video Jason!! I bought my '12 Z06 just over three months ago and I'm having the heads, etc. addressed by RPM this week. Your advice to "just get it done!" is spot on and should NOT sway us from not buying this car as it is an epic bargain!! Mine will be used on track as well as street once she's "fixed" but, like yours has not seen much drive time since the purchase "because"... REALLY looking forward to being able to DRIVE the car once the work is done.
Have a 2011 Z06/Z07. I ordered it and have been the only owner. This is a "track car only" for me. All miles have come from driving to and from Autobahn Country Club and Road America, and on those two tracks in the advanced run groups. Chassis is set up for this application, the engine is stock right down to the air filter. On the track I shift between 5,800 and 6,000 rpm. 16,000 total miles on the car. It receives excellent maintenance. Runs great; no plans to open it up.
my 2007 had the bad valve guides, you should get regular oil analysis to check for titanium. I had significant increases at 24,000 miles. Pulled the heads and found heavily worn valve guides, GMPP fixed it cost the General $7.000 but now all good. Analyze your oil please, I used Black Stone labs its only $35. Please do it.
You can add ABLE Chevrolet in Rio Vista CA. They changed mine out. They race those cars. They know what they are doing. My valve trane after the "fix" was very obviously noticable more tight & quiet on the drive home that the clancky noises it made on the way in. Just Do It!!
I love the way fixers say it has been fixed. lol. You might want to find out what's wrong with that exhaust valve/guide. Some fixers just change the guide material. I think the exhaust valve itself should be replaced with something way better than the Chevy valve. Having a 1.8 rocker ratio I think the ls7 needs roller rocker tips as well to slow the wear factor but with a good valve and having the run out checked from time to time you can prevent catastrophe.
I visited a garage that specialized in prepping high performance rally cars in the UK. These vehicles were pushed HARD on track days, everyone expected that an engine that gets pushed to the extreme REQUIRES extreme maintainance. I saw vehicles torn down after a couple rallies, the owners expect a high level of preventative maintenance.
This is it right here. Most of the dropped valves are from cars that have been tracked, yes some aren't. Yes if you track a car the engine must be refreshed. No, there is no permanent fix. Run 0-30 oil and delete your oil cooler.
Truth! I was fortunate, I recently bought a '06 and the head, mild cam, and dyno tune was done by the previous owner. I tracked down the shops and was able to get copies of the invoices for the work that was done and it is all documented. Odd thing I have noticed is that heads that have been fixed in cars and those that have not been fixed dont seem to affect asking prices too much.
Thanks for the comment. Your last sentence has me wondering...are you saying that you think the fixed heads should increase the asking price of the car?
I used engine oil analysis to detect the valve guide issue. With oil analysis at every oil change since new, I had an engine health life record, at 21,000 titanium started to show up in the oil. at 24,000 miles it was significant. I had my best Shop pull the heads and invite the GMPP inspector to witness the disassembly. the Valves were so loose the fell out of the head as soon as the retainer was removed. GMPP Agreed with the diagnosis after threatening not to pay for head removal if no valve guide wear was found. $7,000 later, new heads and valves. I had to pay to remove the oil pan and clean out rocker bearings that had fallen out. they were clustered around the oil pickup??????? Result was engine fixed and reliable, but Engine Oil Analysis was the key to early detection and preventing the valve failure and dropping with engine destruction. If you own a LS7 get the oil Analyzed for peace of mind, its $35 at BlackStone Labs. Cheap insurance.
I'm a little late to this but I watched a video of a guy who had his oil checked and then it immediately blew up (within 50 miles I believe). If memory serves me right his oil came back with no red flags or warning signs. It can't hurt to have the oil checked but I don't think it's fool proof on some of these. P.s. jealous you have a C6Z, it's my dream car.
Great question. It largely comes down to to cost and goal. An aftermarket set of heads set up right costs a lot more than a set of stock GM LS7 heads reworked. If you're not trying to make 1,000 horsepower, a stock set can make good power at a lower cost.
My FED "fixed" heads dropped an exhaust valve and took out the entire engine, so I personally don't think that "fixed" heads are the end all be all for this problem. I think it's a combination of bad valve angle geometry, pad style rockers, loose guide to valve tolerance, and sodium filled hollow stem exh valves. Additionally, for cases this still happens on fixed heads, is when running aggressive cams that have higher lift than stock, the pad style rockers start to induce a side load against the valves and this can contribute to premature guide wear. However, this problem has been known to happen in completely stock engines so who knows exactly what the bottom line factor is, but it certainly is a real issue with the LS7. Nice vid explaining it to all the naysayers.
Man that is a rip off. Buying a car you're not comfortable driving in fear of if it breaks ya gonna have to shell out a lot of $$$. That sucks. Good info bruh.
Great video Jason! Like I mentioned to you back in November during SEMA '17 If someone has a factory warranty to also look into an extended factory powertrain warranty if they do not want to go the remove and repair route. I've personally seen that warranty cover the cost of one new engine and a second set of cylinder heads and one transmission. YMMV.
What a drag. I was thinking about getting something with an LS7 if I ever upgrade again, but I'm not ever sure its worth the cost. All the fastest guys I know are running old Honda S2000's, STi's, old M3's, etc... cars that are way cheaper to run hard and replace parts when needed yet still hardly hold anyone back in terms of performance in real life.
Glad it was helpful. I know some will say that it doesn't happen with the Z/28, but I know of some who have experienced it with theirs. Better safe than sorry! Plus...like I said...a good time to upgrade the cam and port the heads. 😀
Sold my mint s2000 for $26,000 and I used it to buy my dream car, a 2011 Z06 with 10k miles. The drive home, from Macon GA to Pensacola Florida and my dream car became my worst nightmare. Didn’t even make it out of Georgia before I had my failure. The bank was dope af and ended up using a lemon law somehow and I was able to get back the 26,000 I put down and I got another z06 but I bought one that had built heads already. As much as I wanted an unmolested corvette, it’s just not smart when it comes to the 427. It still has low miles and I don’t have to worry about dropping a valve anymore. But now I wanna keep modifying. I have a Texas speed cam on its way as I type this out and I’ve already installed a corsa extreme exhaust
Pontiac Ram Air 5 Tunnel Port engines suffered a similar problem with the sodium filled exhaust valve - Destroying many of these incredibly rare engines. I had assumed it was from deficiency in the early technology of manufacturing this valve. (Quality) After listening to your video it seems possible that it was an intolerance to excessive guide clearance (wearing) like you are describing with the LS7, possibly accelerated by high valve spring loads.
FACT If you are using a machined OEM ls7 casting bronze guides stainless exhaust valves etc you are only hitting reset on the problem period!!!!! Check them after 10k miles trust me
Good point, I have seen your videos before. So just to make sure I am following, you say that using all OEM parts and machining the seats and guides to be concentric still doesn't fix the issue?
I'm around these motors virtually every day of my life and the vast majority of them that i work on are found in the 2013 427 convertibles...rare cars...and the Z06. The common strain that myself and most all other techs have found is that the LS7 valve situation, though rare, was consistent with incorrect servicing procedures...incorrect oil viscosities used...lack of adherence to correct oil/filter service intervals...and drivers who beat the living shit out of their cars.
I may be about to buy an 07 Z06 with 8k miles. It’s completely stock. Do you have any advice on what to do to keep it from dropping the valve? I won’t be tracking this car and I doubt I’ll take it to redline. I just want it to be reliable enough to enjoy it without worry.
@@keelandavis Drive it sensibly...avoid bouncing the thing off the rev-limiter...religiously adhere recommended service intervals and oil viscosity...always reset oil life service light when doing the actual service...run a quality synthetic and the GM-Delco filter. you'll be fine.
@@keelandavis How you drive them and how much makes no difference to the issue. There is much anecdotal evidence of low mileage creampuffs dropping valves. Want to keep it from dropping a valve? Get the heads fixed. simple enough.
Mod list! Dynatech coated headers Vararam cold air intake Fast 102 intake 102 Millimeter throttle body Qm 600 cam BTR 660 springs Chrome molly push rods CHE rocker arms WCCH Stage 2 cylinder heads Port and polished Decked 30 thousands MGW short throw shifter B&B Bullet exhaust... 93 Octane tune. Car put down 565rwhp and 501 rwtq. Also have every stock part taken off of vehicle goes with the car.
Thank you for info! I haven't been driving mine for two years now, due to hearing of this valve issue. You've just reinforced my decision not to. Unfortunately I live in Northern BC Canada and can't find a legit shop I trust. Also I don't fully understand what "absolutely" needs completed on the heads. I'm looking to keep mine stock, no cam ect, but want just the needed repairs. Seems every thread I read recommends different head component/repair needs? I'll get it figured out, but wanted to thank you for sharing a definite need for us Z06 owners. Best of luck in new engine swap, and god bless, ehh :-) 🇨🇦
I’m the second owner of a 2006 C6 Z06 bought it 11,000 miles it now has over 40,000 I’ve never had an issues and I definitely don’t baby my car. I used to take it to the drag strip every chance I could for a few years until I moved States. Could the 2006 model be exempt from this valve issue..? More are Cold air intake, full aftermarket exhaust.
Had my son’s heads fixed by AHP at 38,000 miles. I just pulled them at 68,000 miles due to him cracking a cylinder. The reworked AHP heads are bad again. .005 clearance on 9 valves, 1 has .007. Spec is .001~service limit of .003. They are at a machine shop getting new guides again, and a valve job to insure they are concentric. Even the fixed heads won’t last. Word to the wise..
Y'know.. I was just looking at C6 Z06's.. Cross shopping between 997 911 Carrera S's and the Vette seemed the better proposition because the 911's have IMS bearing issues, and the Z06 is more bang for the buck... Now, I'm learning that the Z06's will drop valves and grenade engines?? Sigh....
I cannot speak for the 997 as I am not too familiar with them. However, the fix can be very affordable for the LS7. Around $1,400 if you can do the head swap yourself.
@365 AutoDrive A good point, there are some that have made it to high miles with no issues and proper maintenance. However, there are also some that have made it to only a few thousand miles with zero competition use and more than the required maintenance. I have also seen people post the opposite...avoid the early ones and get a later one. I think there is the problem that rises to the top the most...there is just no way to tell for sure.
I’m the second owner of a 2006 C6 Z06 bought it 11,000 miles it now has over 40,000 I’ve never had an issues and I definitely don’t baby my car. I used to take it to the drag strip every chance I could for a few years until I moved States. Could the 2006 model be exempt from this valve issue..? More are Cold air intake, full aftermarket exhaust. Jason's Garage
@@raulbarron7580 Not necessarily exempt, but an exception to what seems to be a common issue. Have you taken the valve covers orr and taken a look at things?
I realize that this is an old thread, but thought I'd throw my 2 cents in. (porsche owner for 10+ years). If you get a 2010 thru 2012 997 it has the DFI motor. Hence no IMS. The IMS issue is over publicized. The single row IMS bearing (2005-2006) used on the M96 motor was/is more prone to failure than the double row bearing (2007-2009).
How much does the repair cost?I'm looking at 1at a dealer that has a mild cam , msd, intake ,and full exhaust....there not sure if heads have been addressed.
That's like asking "how much does a car cost?" 😀 The answer depends on who you buy from, what cores are used, what options you add. As you might have seen in my other videos about this, I went with American Heritage Performance and their LS7 reworked heads start at around $1,500 and go from there...not including labor, of course.
@@InJasonsGarage I have been reading from a performance shop that they have narrowed it down to 2008 to 2011 are the only Z06s affected by incorrect manufactured heads....have you heard this?
@@smm7540 Yes, I have heard it. And I would say that for every time I have heard it...I have also heard someone saying it is not accurate because it has happened to LS7's manufactured outside of those years. Which shop is saying this?
Great video thank you for taking the time. I was considering getting an Ls7 crate engine in a couple months for my project build. Guess now I need to research if the problem still exists on new crate motors before I purchase. Thanks again
There's always a lot of differing opinions with this situation, and if the problems extended to the crate motors has theories as well. Hard to say for sure , there is no solid answer that I know of. I'd say that if you are going to buy a crate engine, have the valves checked just in case.
parts wouldn't be his fault even if did dude take his advice. That's totally on the owner. To take 1 guys advice off a TH-cam comment seems ignorant eh? You calling him ignorant?
After pulling and working and porting on many heads. I dont believe the guides were at fault here.sodiam filled exaust valves. That is what caused the guides 2 go bad.
Wowee, and I am seriously going to look at a 2006 Z06 tomorrow evening! The owner said the heads have been "checked" but not changed. Oh well. Who knows?
2020, I sold my 2016 Cadillac XTS Vsport. Stuck valve, requiring new heads....started looking at C5 z06s....but then quickly got hooked on 427......c6 platform.....king of NA.... since then I've read about every thread/post on the ls7. I was actually hoping for more indeptth. What fixes guide wear.....then there's a huge debate on stock intake valves....sodium filled stainless steel...how their too thin and fail from heat...what causes the heat....exhaust valves need to be upgraded?....hmm, now let's talk about trunnion upgrade....plenty of threads saying steer clear of comp cams kit (failure) and to go with Straub or ...is it btr.....what about the titanium coating coming off the pushrods? I think pushrods is right.... plenty of threads saying stock heads fixed only to fail after....just read where 1 guy actually got WCCH heads and 30k miles later....FAILURE....some don't like Frankenstein.....some say AHP have issues.... watch RACE PROVEN MOTORSPORTS do a thousand HCI setups on the C6Z...... this all started because I wanted to ad a A&A supercharger to the C6Z ( better not unless fully forged lol) like soo many do to the ls6 C5Z06....I'm still so confused, I think it would be easier just to go with a already done and extremely well documented C5z06 600whp A&A with supporting engine mods,meth, clutch, trans, and rear diff along with all the suspension goodies and some CCW wheels DONE....the LS7 as bad ass as it sounds. As iconic as it is....as sweet as the C6 is....maybe that's why the GS is soo popular. A&A and meth on a GS and you're done..
looking at buying a 2006 zo6 with 100k on it… owner doesn’t know if the heads been fixed… with this high mileage do you think it won’t have the valve problem ?
There's no way to tell for sure. It could go on the drive home, it could go another 100k miles. That's the biggest problem, it is a ticking time bomb with no way to tell how many ticks it takes to blow.
I'm seriously considering a C6 Z. But I'm concerned about this problem and have a specific question. If I buy the Vette and get new heads/cam, will that end any past GM problems around this issue from now on for all intensive purposes? Life comes naturally with headaches without me adding to them.
The best way to look at having the heads fixed is it is believed to reduce the chances of the problem happening to you because it is fixing a known defect.
I had the same problem had the heads done. Eddie shop in Dearborn livernois Motorsports. Had the heads ported valve guides done and they did a poor job motor steel detonated NGM did not stand behind the product. At all I am done with GM in their products I would love to have another Corvette. But I'm afraid very little trust in GM terrible product
The problem is also with the valve train. The rockers push the valves at an angle, and with the hollow stem valve chevy dropped in it breaks. Lots of problems with this motor...
is there a way to tell if the fix has been done without opening the motor? considering buying one but the previous owner isn’t the original owner so doesn’t know if it’s been addressed
One quick way is to pull the valve covers off and see if there is anything that doesn't look factory. Reference this video: th-cam.com/video/3wxM568im6I/w-d-xo.html
I had a 2006 Z06 and sold it. I think its a bunch of shit to have to fix an issue like this or worry about a new engine. Im a car guy and would love to believe in this one. But a supercharged gt500 has proved to be reliable and pretty dam fun to drive.
You might want to do a search for "gt500 engine failures" before you write that check. They have had their share of them as well...but I agree fun to drive!
You sound like a true blue Chevy guy. I have checked out the GT 500 and its issues. The truth be known every performance vehicle has some sort of bug a boo Porsche included. But you’ve got to pick your path of least resistance and I wasn’t willing to take that with the motor potentially going out of the Z06 .Just my opinion. I’ve owned three vettes in 2 Shelby’s. In numerous others:. jeeps you name it and everyone of them has something
@@gws108 I do indeed lean more toward the bowtie, I always have but I am certainly not ignorant of other great makes and models. After my last reply, I was thinking the same thing...I cannot recall a performance engine that didn't have some issues, just like you said. You are also right, it all depends on what you are willing to deal with. The consensus seems to show that typically, once the head issue is addressed, the LS7 is pretty solid after that. I am OK with it. :) I love this engine. At least...for now! 😀
Since I made this video I have received conflicting reports on that one. Some solid sources told me they were fixed for the Z/28 as well as crate engines, but I have still heard reports of the issue happening anyway. So it is really hard to say and I don't think we will ever know for sure and possibly, there is no single answer. My advice to be safe...consider it a possible problem and have it checked.
Valves are usually about redline and springs. The guides are concentric enough to run it, so that's not it, lol. If you hear ticking then failure, it broke something. Like the inner spring. This stuff is either a bad part or user error. And that's cars.
@@jackpaullus2643 I've come to understand that the pressed-in rocker studs pull loose, then the valve geometry binds, timing is affected and valves break. People have reported hearing noise and then complete failure. Which means engine rebuild. Stop driving the car NOW, you should have stopped before this, you are already in the RED. Pull the heads, get screw-in studs, check the guides, valves and seats. It is a manufacturer problem. Join a class action suit for compensation...Or loose the motor and/or car...On the bright side, have long tube headers installed and free flowing exhaust. Don't cheap-out on it.
@@jackpaullus2643 yeah, and chewed lobes from moving lifters. But the broken valve/wasted head is from the pressed stud pulling, wearing the valve guide, and extending the valve into the piston. It's negligence, and a known concept going back decades. There's no excuse. Cheers
The valve broke from coming down and sit on one side of the seat first from worn out guide. The owner should be able to hear a double click valve chatter for a while before this happen. I have work on European cylinder heads for over 50 years they all have hollow stem sodium cooled exhaust valve, they all have worn out guides , never had a broken valve. They might not have as much spring pressure as the corvette, but still rev within 1000 rpm.
I purchased a crate LS7 from GM Performance this year (2020). It seems unclear whether GM corrected the issue with their current crate engines? Does the LS7 in the Z/28 have the same problem? The engine is going into a dedicated track car that won't see a lot of miles but will do probably 15-20 track days a year. My plan was to get the heads and motor inspected and refreshed every other year, so about every 10k miles. I'm half tempted to get the heads inspected before we even put the car on the dyno.
I have been told different stories about the Z/28 since I made this video. While a source very close to the car said they did fix it, I have also seen reports of very similar failures. I don't know if it is the same issue or not. The same goes with crate engines. I think you are on the right path to check it, especially with your purposes of it.
@@703z06 I have just ordered the same LS7 570HP crate for my car. Here all this time later, hoping the issue has been fixed. How is yours? How many miles? What kind if rpms are you seeing? Dyno?
The common thought it you only have to do it once if they are done right. WCCH does pretty good work but just for good measure, give them a call and see what they recommend since they did your heads.
how much did it cost to replace your heads and who would you recommend to do the work. I live in north east Mississippi and hard to find someone that I could trust to do it
See my other videos about this at bit.ly/ls7fixvids, I used AHP for their heads and had a great experience. For installation, I wish I could help but I don't know the shops in your area. Sorry!!
Jason I got a 2008 ZO6 with 13,000 miles on it now and I'm torn about the head issue not knowing all of all of them need to be done if there's some signs that you here before indicating when it should be done like on your car did you hear any freaking anything that made you think the valves could be warned I better check them or was it just from all the other issues you've heard from others who would you recommend to do the work and are you happy with the kit that you got?
From my research, there has been no common indication that there is an issue and pending failure. Sometimes there's noise, sometimes there isn't. I had no indication myself, I just took the advice from others. At the very least, have the heads pulled and check the valves but even then, you will likely need to have the heads redone. I have been extremely happy with the heads/cam I got from AHP. Give them a call and tell them your concerns, and tell them I sent you. They will set you up with exactly what you need and nothing more. See my other videos in my channel for unboxing, driving impressions, etc.
@@InJasonsGarage tha is so much will do ... I've been contemplating if it really needs it it's got 13,000 miles it's been baby beyond belief but I don't want to take a chance I don't think it's worth the risk myself
@@krisi.2011 That's how I look at it. You spend $45k+ on a very special and unique car, you spend a lot more money and time on top of that taking good care of it. Despite that fact that this shouldn't be an issue...it most likely is and issue and is the cost of entry to owning an LS7 powered car. So unfortunately, it is better to spend ~$2k of grand to prevent the chance of a catastrophic failure costing ~$15k if you want to play in that realm.
I don't know if that should stop you, the fix is as low as $1500 and labor costs, and after that...you have a no frills supercar that is very affordable by comparison.
Hi so I’m planning on buying an Ls 7 swapped rx-7 and my question for you is: how often do I need to get the heads fixed? Also is there a way to tell if the person I’m buying it from already has fixed it just by looking at it?
If you do it right, only once is the popular consensus. The easiest way to check is to ask the person you are buying from. If they say "huh?" then you might want to have them fixed. You cannot tell visually, you need to remove the heads have someone who knows what to look for see how much play there is to the valve stems, indicating out of spec valve guide wear.
I heard about the problem, ignored it, now I'm about $5000 out to fix the head, the piston, the sleeve and labor. I lucked out and the block didnt crack.
I made this video in hopes that it would prevent this from happening, so I am always sad when I hear that it does. Sounds like you got luckier than some. Hope it gets fixed cleanly and you enjoy your car more than ever.
I think it is important to have someone who knows what they are doing look at all the valves, just to be safe. It is a small piece of insurance in my opinion. See this video: th-cam.com/video/3wxM568im6I/w-d-xo.html
@@InJasonsGarage true. I am hoping to buy a z06 that has the heads replaced according to the carfax. Although that’s kinda vague, I wish I knew more about the procedure it went through lol
Questions, I’ve heard this “head problem” exists with the LS7 engine, but does it also occur in the other model’s engines (ie, base, grand sport, Z51, etc...?) I’m considering purchasing a Corvette within the next six months, and I haven’t heard much concerning those engines with problems like this “head issue”... Also, does this head issue carry over into the C7 model years as well...? Thanks in advance for any answers... 👍🏾👍🏾
This specific issue is regarding the LS7. That is not to say that no other engine cannot have similar issues, but is believed to be much more common with the LS7.
I'm looking at a c6 z06. The said he had preventative maintenance done on it because of what happened to his buddy's ls7. The guy told me it's still the stock heads, but the valves, stems, springs etc have been changed. Is it possible to fix the valve drop issue still using the stock heads?
Yes, a lot of reputable places use a factory head but rework the guides and such to prevent or at least reduce the chances of it failing. Did he say who did the work and the parts used?
@@InJasonsGarage A shop in Michigan, Alternative auto performance. I asked him if he could find the receipt for it. He said it's been awhile but he will look for it
@@camonly849 I used to live not far from Alternative Auto, and I was an acquaintance of the owner Lidio. It has been a few years since I talked to him, but he is pretty much a legend in the Mustang world and expanded into LS stuff around 10 years ago. He is good guy and is known for doing good work.
2004-2008 Audi S4 BHF Timing Chain, valve guide wear, and/or cylinder bore scoring 2003-2005 Porsche 911 non-Turbo /non-GTRS IMS bearing design flaw 2006-2013 Corvette Z06 Valve Guide out of round machining flaw, design spec flaw, or material selection flaw These are fun to catalogue.
Hello sir I seen your video and others I was about to buy a 13 model yesterday for a good price with 15,000 miles but the engine issues held me from doing it and my question to you would be to fix everything you’d recommend what would it cost on one of these engines for piece of mind ?
If you want an LS7 powered car, you shouldn't let this issue stop you. Just factor in the cost of having the heads fixed. Different shops have different prices but go with one that has LS7 head work experience. Check out this video: th-cam.com/video/IjZsagCk-x8/w-d-xo.html
I want one and I plan on getting the head’s done. Any tips you can recommend? I’m not afraid of buying the car, I just want to build a good reliable street car 👍🏿
My opinion is that they didn't. Some may disagree...but others with varying years of LS7 engines will agree, and paid the price. What I still understand to this day is that there is no exact answer, so it is still and may always be a roll of the dice.
Looking at buying a 06 with 98k miles, and original heads. Runs like a top, and was recently at Chevy for a PCM issue and nothing said about any valve noise, etc. Seller says he is aware of the valve issue, but if it’s made it 98k, it’s obviously not one of the engines affected by the wear issue. What are your thoughts?
My 100% honest opinion...unless you got the cat on a screamin' deal and can afford to replace the engine if something goes wrong, get the valves checked by someone who knows what to look for. Even though it made it 98k miles, it doesn't mean it will go another 1k miles. It has happened with low mileage cars, high mileage cars, and everything in between. Sure, there are some that never had the issue but I'd only take that risk if you can afford it
@@InJasonsGarage2008 through 2011 ZO6 were affected. When you get in problems with this cars when you modify it that's when problems happen. I guess you think you know more than Paul Kerner the top Corvette expert in the country.
@@richardcerritelli9657 I am not claiming to know more than anyone, but I too have done my research. I also know that those who work for GM like to keep their jobs. If you ask people outside of GM, you get different answers...including people who have had the issue with their stock LS7 engines outside of the 2008-2011 range. Like this guy with his stock 2007... th-cam.com/play/PLwpV2P5J-lOA812dx1WTgyk1k2J98T-VO.html
Good info, sticking with a c6 GS then....unless the down payment is low enuff. Can a shop tell if the heads were fixed on a used car 37k miles before you buy?
Don’t buy replacement GM heads. If you have a reputable competent aftermarket specialist like Lingenfelter rebuild your heads with superior aftermarket parts the issue won’t come back.
Good to know. I am going to look at a 2006 Z06 tomorrow. The owner says the heads have been "checked" but not changed. I may just have to go ahead and figure that cost into the car. It has about 52k miles
Th3CrypticGamer - I would take the Kelley Blue Book Value and subtract the materials and labor cost for a Lingenfelter or Katech head exchange. “Check” means absolutely nothing - even if he could show you the dealer labor paperwork on it. Unless you have a warranty with no deductible it’s all on you. Assume it’s a ticking time bomb.
I don't have anyone that I can personally recommend in that area, but see my other videos about American Heritage Performance. I had very good luck and service with them.
Also, i would be concerned if i where you if im paying 1/3 for a new motor and install. Im sure you can oick up a used ls7 for 4k and another 1,000-2,000 for install and tuning. That way less than 10k but yes. It is still very very expensive. I’d rather pay 2K for new heads + install than a new motor lol
Sure, if you know the history of that used LS7 engine. That's a great alternative. And I agree, I'd rather just pay to have the heads addressed and reduce the chances of an issue. In fact...that's exactly what I did! See my other videos. 😎
It depends on who you ask, but it is usually said to be the valve guides but some say there's more to it than that. There's also a good article here: katechengines.com/wp-content/uploads/TheSHOPMag_7-17.pdf
@@InJasonsGarage Thanks. Wouldn't upload but I can go to the site probably and pick it off. All the money they spend putting into that engine to get 500 horsepower and they scrimp on the valve guides. Admittedly, that just screams Chevrolet.
That is not known for sure. Some say that they haven't been fixed, others say they have. I'd like to think that they have been fixed but I am definitely not the one who can confirm. I think that's kind of the problem...we just don't know for sure.
It doesn't really suck...only if it blows. :) I suppose you don't HAVE to fix it and you can take the chance. Many have gotten away with it, but quite a few have no. Once it is fixed...oh yeah, the power and torque makes it all worthwhile.
www.superchevy.com/how-to/1406-how-to-maintain-valvetrain-stability-ls7-exhaust-valves Worth the read.... testing regarding stability using an LS7 test rig to measure stability and valve bounce at speeds up to 7900 rpm. The little shop that did the testing? Katech... yea, they probably know what they’re talking about. Hope this helps answer some questions. I also tried to see if I could figure out how many failures had occurred in all LS7S using data on several forms. Looks to be a failure rate of 1/4 to 1/2 of 1% for all LS7 produced from what I could figure out. Not saying this is 100% correct but I think it’s close. The performance shop I use (in Garner NC) has seen 1 dropped valve but has modified hundreds of LS7s. So yes the problem is real but and no one wants to kill a $15-20K engine but it doesn’t happen with high frequency.
I actually used to live around 5 miles from Katech and I trust them. They know their stuff. I also know other people that are "up the chain" in GM performance, and the higher the chain goes, the louder the message is that it should be at least looked into if you have an LS7. It is damn near a race motor and race motors are not without needed maintenance and frequent checks. This situation reflects that. There has been nothing quite like this engine before or since, in my opinion. That is why I bought the one I did. It is a tax I am happy to pay, because it is unparalleled in performance and will become legendary, even more than it is now. I say this not because I own one, but because I researched it long ago, and my findings have not changed.
Jason's Garage - had a lifter failure in mine about 6 months after I bought it. Was told heads look fine. The motor had about 60K miles on it at that time. So motor was refreshed. I think I will do the heads in the near future for piece of mind and take advantage of the performance bump. The LS7 is pretty amazing to give the performance it does and still remain fairly civilized in the process. I went back with a LS7S cam from Texas Speed. Car makes pretty good power with stock heads (near 550 wheel). Honestly the pilot super sports can’t handle the power now until about 3 rd gear in warm weather and forget it when under 75 degrees or damp. Super fun car.
Hey guys hope someone can help me out, I just got a 2006 Z06 with 20k miles on it, I know about the valve drop issue and I’m prepping for it. Just wondering, when I get the American Heritage Performance headers is there anything else I should change? Maybe get checked? Trying to keep it as least expensive as I can without cutting corners. Any fellow Z06 owners have any advice to share? Thanks guys.
Least expensive? Get the AHP package 4 heads. Swap them out, done. Got a bit more in your budget and want a little bit more power? Have them do a street port. Got some more in your budget and want even more power? Get their cam kit.
@@MrBrightSide784 No worries man...it is cheap insurance. Even if everyone is wrong about the valve issue...it is still worth the peace of mind...just in case. :) Let me know how it goes.
Save your money headers are a waste of time on this car you'll get no horsepower increase the only thing they're good for is giving you a headache and making your wallet lighter lighter.
How is the reliability with a set of fixed heads on the engine? I know this valve issue is the biggest problem with these engines. Thank you for the very informative video!
Even "fixed" heads have been known to drop valves. My FED fixed heads dropped the exhaust valve last year. I was running an aftermarket cam with only .635 lift, and less than 10k miles on build, but some say this is enough lift that with the pad style rockers at full lift it puts a side load on the valves and causes premature wear to guides. Definitely upgrade to roller rockers.
Some say yes, some say no. I'd like to believe they did, and it would be logical to think they did. I personally haven't heard any issues about the crate engines. I know this doesn't help at all but if you happen to hear a more concrete answer, please let me know.
@@time_on_target If you don't mind, can you ask the same question to who you bought it from and let me know their answer? I am very curious. Also...what are you putting it in?
In Jason's Garage I bought the GM performance LS7 crate from a GM dealership in WI and had it shipped to me in TX. It’s going on my 1967 mustang track car. Vorshlag here in Dallas is handling most of the build for me. 500hp in a 2600lb car should be fun.
@@InJasonsGarage It was a LS7 with a tunnel ram and duel throttle bodies. I had never seen a LS style motor with a old school tunnel ram on it. I have pictures of it. BA!!
The stock components that come with this head or not adequate, #1 use a solid Enconel steel opposed to a hollow stem exhaust valve, #2 nurl and reem the top half of the guide to get oil stored into the guide
The stock exhaust valve is a hollow sodium filled valve (correct me if I'm wrong). What if you simply replace the valves with a solid steel valves? Will they still break and drop in the burning chamber?
Good question. The problem isn't necessarily with the valve, but the machining of the valve guide not being concentric with the valve seat. If you don't fix that, any valve swap will not be a solution. Plus, you have to consider the valvetrain weight. The LS7 can rev very high for being such a large engine thanks to a very lightweight valvetrain. Heavier valves will change the dynamics of the rest of the system.
Jason's Garage Hmm what if you swap the LS7 heads for good flowing LS3 heads? I noticed some LS7 crate engines come with LS3 heads. Here's a sample: www.mastmotorsports.com/collections/750-hp/products/ls7-427-black-label-900-supercharged-crate-engine-900hp Are other LS engines also affected by the valve guide issue or is it just the LS7?
That engine might have LS3 heads because it is boosted and doesn't need LS7 heads. Yes, you can put LS3 heads on an LS7. You may need to check and piston to valve clearance and such and I think you would also need to replace the intake as well. You would loose a decent amount of power and you can fix the LS7 heads for less cost than the LS3 heads and intake.
The assumption is the problem exists with all factory/OEM LS7 engines. There is no real and actual confirmation either way, so my opinion is no, not safe if staying "better safe than sorry".
![ประสบการณ์ จ้าง Developer ที่ผมจะไม่มีวันลืม [ภาค1]](http://i.ytimg.com/vi/bzivN4KDg-k/mqdefault.jpg)
I saw your video before I bought my 06 Z06. My ignorant ass thought all folks out there including you were just over-reacting. I bought my Z06 about a month ago and I took my chances. Few days ago, my LS7 dropped a valve and blew up. Now I'm facing 16.5k repair bill just for the new crate engine and labor (I gotta get it fixed whether or not I want to keep the car). The issue is damn real guys and it is terrifying. Get your heads fixed if you haven't already done so, unless you want to put yourself into a big financial trouble. Even the new crate LS7s have valve guide issue and I must get them fixed before the 2-year warranty expires. Don't be an idiot like me and get your heads fixed for God's sake. Thanks for the good video Jason.
WOW...I am SO sorry to hear that. A lot of people say that it is overblown and a non-issue, yet I her about these things all the time still. Again, I am sorry that happened. Check with AHP...they just released their own engines and oh boy...do they look good.
@@InJasonsGarage I couldn't afford AHP's LS7 with pre-fixed heads (go for $14.4k +shipping & tax) so I got cheapest LS7 crate with chevy performance 2-yr warranty. I want to get the heads done ASAP regardless of warranty period. I just don't want to worry about valve drop when I'm driving. This is such a pain in the ass if you are not prepared for near $20k repairs. Hope people out there realize how terrifying the issue is and get their heads fixed... No more LS7 needs to blow up due to owner's ignorance.
Ouch...that hurts. 😨
Happened to my 14 stingray too..
So the "new" LS7 crate issue ship with the defect also? GM refuse to correct the problem, even on the replacement engine? Wanted to make sure I read that correctly, seems very strange.
gm should be paying for that...smh
Valve guide wear should be checked every 20k at minimum even after the repair has been made. The high redline in the ls7 causes valve motion that wears valve guides out even if the guides have the right valve guide to valve stem clearance and even if the guide machining is concentric.
Great video Jason!! I bought my '12 Z06 just over three months ago and I'm having the heads, etc. addressed by RPM this week. Your advice to "just get it done!" is spot on and should NOT sway us from not buying this car as it is an epic bargain!! Mine will be used on track as well as street once she's "fixed" but, like yours has not seen much drive time since the purchase "because"... REALLY looking forward to being able to DRIVE the car once the work is done.
How did it all turn out? RPM does good work.
How's the RPM work holding up after 4 years?
Have a 2011 Z06/Z07. I ordered it and have been the only owner. This is a "track car only" for me. All miles have come from driving to and from Autobahn Country Club and Road America, and on those two tracks in the advanced run groups. Chassis is set up for this application, the engine is stock right down to the air filter. On the track I shift between 5,800 and 6,000 rpm. 16,000 total miles on the car. It receives excellent maintenance. Runs great; no plans to open it up.
my 2007 had the bad valve guides, you should get regular oil analysis to check for titanium. I had significant increases at 24,000 miles. Pulled the heads and found heavily worn valve guides, GMPP fixed it cost the General $7.000 but now all good. Analyze your oil please, I used Black Stone labs its only $35. Please do it.
@@DennisMurphey Thanks for your thoughtful message and concern.
Sounds like a good idea, I just sent for my test kit. Thanks Dennis.
I bet you blow your car up and cry about iy
You can add ABLE Chevrolet in Rio Vista CA. They changed mine out. They race those cars. They know what they are doing. My valve trane after the "fix" was very obviously noticable more tight & quiet on the drive home that the clancky noises it made on the way in. Just Do It!!
I love the way fixers say it has been fixed. lol. You might want to find out what's wrong with that exhaust valve/guide. Some fixers just change the guide material. I think the exhaust valve itself should be replaced with something way better than the Chevy valve. Having a 1.8 rocker ratio I think the ls7 needs roller rocker tips as well to slow the wear factor but with a good valve and having the run out checked from time to time you can prevent catastrophe.
I visited a garage that specialized in prepping high performance rally cars in the UK. These vehicles were pushed HARD on track days, everyone expected that an engine that gets pushed to the extreme REQUIRES extreme maintainance. I saw vehicles torn down after a couple rallies, the owners expect a high level of preventative maintenance.
This is it right here. Most of the dropped valves are from cars that have been tracked, yes some aren't. Yes if you track a car the engine must be refreshed. No, there is no permanent fix. Run 0-30 oil and delete your oil cooler.
Truth! I was fortunate, I recently bought a '06 and the head, mild cam, and dyno tune was done by the previous owner. I tracked down the shops and was able to get copies of the invoices for the work that was done and it is all documented. Odd thing I have noticed is that heads that have been fixed in cars and those that have not been fixed dont seem to affect asking prices too much.
Thanks for the comment. Your last sentence has me wondering...are you saying that you think the fixed heads should increase the asking price of the car?
I hate when youtubers tell us to subscribe... we get it buddy and if we like it we will subscribe..
Well? Did you? 😏
I used engine oil analysis to detect the valve guide issue. With oil analysis at every oil change since new, I had an engine health life record, at 21,000 titanium started to show up in the oil. at 24,000 miles it was significant. I had my best Shop pull the heads and invite the GMPP inspector to witness the disassembly. the Valves were so loose the fell out of the head as soon as the retainer was removed. GMPP Agreed with the diagnosis after threatening not to pay for head removal if no valve guide wear was found. $7,000 later, new heads and valves. I had to pay to remove the oil pan and clean out rocker bearings that had fallen out. they were clustered around the oil pickup??????? Result was engine fixed and reliable, but Engine Oil Analysis was the key to early detection and preventing the valve failure and dropping with engine destruction. If you own a LS7 get the oil Analyzed for peace of mind, its $35 at BlackStone Labs. Cheap insurance.
I just changed my oil and sent a sample to Blackstone. Hope it comes back OK...
I'm a little late to this but I watched a video of a guy who had his oil checked and then it immediately blew up (within 50 miles I believe). If memory serves me right his oil came back with no red flags or warning signs. It can't hurt to have the oil checked but I don't think it's fool proof on some of these. P.s. jealous you have a C6Z, it's my dream car.
Why not just buy aftermarket heads rather than have the gm ones fixed.
Great question. It largely comes down to to cost and goal. An aftermarket set of heads set up right costs a lot more than a set of stock GM LS7 heads reworked. If you're not trying to make 1,000 horsepower, a stock set can make good power at a lower cost.
Cats, dogs and LS7's. Have them fixed 😅
Hahahaha! Well played.
Thank you for sharing this information! Really appreciated.
Glad it was helpful!
I love that Firebird shirt!
Thanks, it is one of my favorites!
My FED "fixed" heads dropped an exhaust valve and took out the entire engine, so I personally don't think that "fixed" heads are the end all be all for this problem. I think it's a combination of bad valve angle geometry, pad style rockers, loose guide to valve tolerance, and sodium filled hollow stem exh valves. Additionally, for cases this still happens on fixed heads, is when running aggressive cams that have higher lift than stock, the pad style rockers start to induce a side load against the valves and this can contribute to premature guide wear. However, this problem has been known to happen in completely stock engines so who knows exactly what the bottom line factor is, but it certainly is a real issue with the LS7. Nice vid explaining it to all the naysayers.
Thanks, you are echoing what I hear a lot of people say.
Nice informative video. I have an '05 that I absolutely love! I've been thinking about an upgrade to a newer gen 6 Z06. Thanks for the great info.👍👍
Glad it was helpful!
Man that is a rip off. Buying a car you're not comfortable driving in fear of if it breaks ya gonna have to shell out a lot of $$$. That sucks. Good info bruh.
Great video Jason! Like I mentioned to you back in November during SEMA '17 If someone has a factory warranty to also look into an extended factory powertrain warranty if they do not want to go the remove and repair route. I've personally seen that warranty cover the cost of one new engine and a second set of cylinder heads and one transmission. YMMV.
Does replacing the heads solve this issue though? This problem is putting me off from buying one
First time seeing you. Great video. Thanks!
Thanks! I'll check into your channel as well! 👍
@@InJasonsGarage thank you so much!
What a drag. I was thinking about getting something with an LS7 if I ever upgrade again, but I'm not ever sure its worth the cost. All the fastest guys I know are running old Honda S2000's, STi's, old M3's, etc... cars that are way cheaper to run hard and replace parts when needed yet still hardly hold anyone back in terms of performance in real life.
Driven or ridden in one yet? If not...you might want to. Just factor in the repair as a preventative measure. It is worth it. :)
I'm looking to get a 2008 C6 Z06 with 12k miles on it. I'm worried about it myself
Abu Nation Did you get it? How’s it treating you?
Thank you, I'm looking at buying a used 2015 z28, and was told to check this issue before I sign papers
Glad it was helpful. I know some will say that it doesn't happen with the Z/28, but I know of some who have experienced it with theirs. Better safe than sorry! Plus...like I said...a good time to upgrade the cam and port the heads. 😀
Sold my mint s2000 for $26,000 and I used it to buy my dream car, a 2011 Z06 with 10k miles. The drive home, from Macon GA to Pensacola Florida and my dream car became my worst nightmare. Didn’t even make it out of Georgia before I had my failure. The bank was dope af and ended up using a lemon law somehow and I was able to get back the 26,000 I put down and I got another z06 but I bought one that had built heads already. As much as I wanted an unmolested corvette, it’s just not smart when it comes to the 427. It still has low miles and I don’t have to worry about dropping a valve anymore. But now I wanna keep modifying. I have a Texas speed cam on its way as I type this out and I’ve already installed a corsa extreme exhaust
Pontiac Ram Air 5 Tunnel Port engines suffered a similar problem with the sodium filled exhaust valve - Destroying many of these incredibly rare engines.
I had assumed it was from deficiency in the early technology of manufacturing this valve. (Quality)
After listening to your video it seems possible that it was an intolerance to excessive guide clearance (wearing) like you are describing with the LS7,
possibly accelerated by high valve spring loads.
FACT If you are using a machined OEM ls7 casting bronze guides stainless exhaust valves etc you are only hitting reset on the problem period!!!!! Check them after 10k miles trust me
Good point, I have seen your videos before. So just to make sure I am following, you say that using all OEM parts and machining the seats and guides to be concentric still doesn't fix the issue?
They are not my videos but that is correct
I'm around these motors virtually every day of my life and the vast majority of them that i work on are found in the 2013 427 convertibles...rare cars...and the Z06. The common strain that myself and most all other techs have found is that the LS7 valve situation, though rare, was consistent with incorrect servicing procedures...incorrect oil viscosities used...lack of adherence to correct oil/filter service intervals...and drivers who beat the living shit out of their cars.
I may be about to buy an 07 Z06 with 8k miles. It’s completely stock. Do you have any advice on what to do to keep it from dropping the valve? I won’t be tracking this car and I doubt I’ll take it to redline. I just want it to be reliable enough to enjoy it without worry.
@@keelandavis Drive it sensibly...avoid bouncing the thing off the rev-limiter...religiously adhere recommended service intervals and oil viscosity...always reset oil life service light when doing the actual service...run a quality synthetic and the GM-Delco filter. you'll be fine.
@@frankcastle5294 awesome, thank you for the response.
and a chevy engine has put up with that since the beginning of time. a gm engine should still run in 40 years or they are going backwards
@@keelandavis How you drive them and how much makes no difference to the issue. There is much anecdotal evidence of low mileage creampuffs dropping valves. Want to keep it from dropping a valve? Get the heads fixed. simple enough.
Mod list!
Dynatech coated headers
Vararam cold air intake
Fast 102 intake
102 Millimeter throttle body
Qm 600 cam
BTR 660 springs
Chrome molly push rods
CHE rocker arms
WCCH Stage 2 cylinder heads
Port and polished
Decked 30 thousands
MGW short throw shifter
B&B Bullet exhaust...
93 Octane tune.
Car put down 565rwhp and 501 rwtq.
Also have every stock part taken off of vehicle goes with the car.
Sounds like a fun ride!
Thank you for info! I haven't been driving mine for two years now, due to hearing of this valve issue. You've just reinforced my decision not to. Unfortunately I live in Northern BC Canada and can't find a legit shop I trust. Also I don't fully understand what "absolutely" needs completed on the heads. I'm looking to keep mine stock, no cam ect, but want just the needed repairs. Seems every thread I read recommends different head component/repair needs? I'll get it figured out, but wanted to thank you for sharing a definite need for us Z06 owners. Best of luck in new engine swap, and god bless, ehh :-) 🇨🇦
Glad I could help! If you are at your wit's end, contact American Heritage Performance. They haven't steered me wrong yet.
I’m the second owner of a 2006 C6 Z06 bought it 11,000 miles it now has over 40,000 I’ve never had an issues and I definitely don’t baby my car. I used to take it to the drag strip every chance I could for a few years until I moved States. Could the 2006 model be exempt from this valve issue..? More are Cold air intake, full aftermarket exhaust.
How’s she running now?
Had my son’s heads fixed by AHP at 38,000 miles. I just pulled them at 68,000 miles due to him cracking a cylinder. The reworked AHP heads are bad again. .005 clearance on 9 valves, 1 has .007. Spec is .001~service limit of .003. They are at a machine shop getting new guides again, and a valve job to insure they are concentric. Even the fixed heads won’t last. Word to the wise..
So even if I get the heads fixed, it’s still not a permanent solution, I was looking at c6 Z06s but now I’m really considering the grand sport
Y'know.. I was just looking at C6 Z06's.. Cross shopping between 997 911 Carrera S's and the Vette seemed the better proposition because the 911's have IMS bearing issues, and the Z06 is more bang for the buck... Now, I'm learning that the Z06's will drop valves and grenade engines?? Sigh....
I cannot speak for the 997 as I am not too familiar with them. However, the fix can be very affordable for the LS7. Around $1,400 if you can do the head swap yourself.
@365 AutoDrive A good point, there are some that have made it to high miles with no issues and proper maintenance. However, there are also some that have made it to only a few thousand miles with zero competition use and more than the required maintenance. I have also seen people post the opposite...avoid the early ones and get a later one.
I think there is the problem that rises to the top the most...there is just no way to tell for sure.
I’m the second owner of a 2006 C6 Z06 bought it 11,000 miles it now has over 40,000 I’ve never had an issues and I definitely don’t baby my car. I used to take it to the drag strip every chance I could for a few years until I moved States. Could the 2006 model be exempt from this valve issue..? More are Cold air intake, full aftermarket exhaust. Jason's Garage
@@raulbarron7580 Not necessarily exempt, but an exception to what seems to be a common issue. Have you taken the valve covers orr and taken a look at things?
I realize that this is an old thread, but thought I'd throw my 2 cents in. (porsche owner for 10+ years). If you get a 2010 thru 2012 997 it has the DFI motor. Hence no IMS. The IMS issue is over publicized. The single row IMS bearing (2005-2006) used on the M96 motor was/is more prone to failure than the double row bearing (2007-2009).
How much does the repair cost?I'm looking at 1at a dealer that has a mild cam , msd, intake ,and full exhaust....there not sure if heads have been addressed.
That's like asking "how much does a car cost?" 😀 The answer depends on who you buy from, what cores are used, what options you add. As you might have seen in my other videos about this, I went with American Heritage Performance and their LS7 reworked heads start at around $1,500 and go from there...not including labor, of course.
@@InJasonsGarage I have been reading from a performance shop that they have narrowed it down to 2008 to 2011 are the only Z06s affected by incorrect manufactured heads....have you heard this?
@@smm7540 Yes, I have heard it. And I would say that for every time I have heard it...I have also heard someone saying it is not accurate because it has happened to LS7's manufactured outside of those years. Which shop is saying this?
Great video thank you for taking the time. I was considering getting an Ls7 crate engine in a couple months for my project build. Guess now I need to research if the problem still exists on new crate motors before I purchase. Thanks again
There's always a lot of differing opinions with this situation, and if the problems extended to the crate motors has theories as well. Hard to say for sure , there is no solid answer that I know of. I'd say that if you are going to buy a crate engine, have the valves checked just in case.
I’m looking at getting a 07 z06 Ron Fellows edition, from my understanding there factory with different heads do you know this information?
I haven't heard that before myself. I'd make sure tat is accurate.
guess im lucky bought mine brand new in 07 and still have it today at 79k and so far no problems
Im about to buy a 06 c6z think i should be fine 50k miles
+paul gumbo you guys are on burrowed time lol
The issue affected 2008-2011 LS7s. Your 07 is probably safe.
@@jaco5187 You willing to buy him a new engine if his blows up because he didn't get it fixed based on your advice.?
parts wouldn't be his fault even if did dude take his advice. That's totally on the owner. To take 1 guys advice off a TH-cam comment seems ignorant eh? You calling him ignorant?
After pulling and working and porting on many heads. I dont believe the guides were at fault here.sodiam filled exaust valves. That is what caused the guides 2 go bad.
If you put new heads, does the problem go away?
Depends on what heads. 😄
@@InJasonsGarage ?
Good information
Thanks
Wowee, and I am seriously going to look at a 2006 Z06 tomorrow evening!
The owner said the heads have been "checked" but not changed. Oh well. Who knows?
2020, I sold my 2016 Cadillac XTS Vsport. Stuck valve, requiring new heads....started looking at C5 z06s....but then quickly got hooked on 427......c6 platform.....king of NA.... since then I've read about every thread/post on the ls7. I was actually hoping for more indeptth. What fixes guide wear.....then there's a huge debate on stock intake valves....sodium filled stainless steel...how their too thin and fail from heat...what causes the heat....exhaust valves need to be upgraded?....hmm, now let's talk about trunnion upgrade....plenty of threads saying steer clear of comp cams kit (failure) and to go with Straub or ...is it btr.....what about the titanium coating coming off the pushrods? I think pushrods is right.... plenty of threads saying stock heads fixed only to fail after....just read where 1 guy actually got WCCH heads and 30k miles later....FAILURE....some don't like Frankenstein.....some say AHP have issues.... watch RACE PROVEN MOTORSPORTS do a thousand HCI setups on the C6Z...... this all started because I wanted to ad a A&A supercharger to the C6Z ( better not unless fully forged lol) like soo many do to the ls6 C5Z06....I'm still so confused, I think it would be easier just to go with a already done and extremely well documented C5z06 600whp A&A with supporting engine mods,meth, clutch, trans, and rear diff along with all the suspension goodies and some CCW wheels DONE....the LS7 as bad ass as it sounds. As iconic as it is....as sweet as the C6 is....maybe that's why the GS is soo popular. A&A and meth on a GS and you're done..
looking at buying a 2006 zo6 with 100k on it… owner doesn’t know if the heads been fixed… with this high mileage do you think it won’t have the valve problem ?
There's no way to tell for sure. It could go on the drive home, it could go another 100k miles. That's the biggest problem, it is a ticking time bomb with no way to tell how many ticks it takes to blow.
Might as well buy a set of after market performance heads.
I'm seriously considering a C6 Z. But I'm concerned about this problem and have a specific question. If I buy the Vette and get new heads/cam, will that end any past GM problems around this issue from now on for all intensive purposes? Life comes naturally with headaches without me adding to them.
The best way to look at having the heads fixed is it is believed to reduce the chances of the problem happening to you because it is fixing a known defect.
I had the same problem had the heads done. Eddie shop in Dearborn livernois Motorsports. Had the heads ported valve guides done and they did a poor job motor steel detonated NGM did not stand behind the product. At all I am done with GM in their products I would love to have another Corvette. But I'm afraid very little trust in GM terrible product
The problem is also with the valve train. The rockers push the valves at an angle, and with the hollow stem valve chevy dropped in it breaks. Lots of problems with this motor...
is there a way to tell if the fix has been done without opening the motor? considering buying one but the previous owner isn’t the original owner so doesn’t know if it’s been addressed
One quick way is to pull the valve covers off and see if there is anything that doesn't look factory. Reference this video: th-cam.com/video/3wxM568im6I/w-d-xo.html
I had a 2006 Z06 and sold it. I think its a bunch of shit to have to fix an issue like this or worry about a new engine. Im a car guy and would love to believe in this one. But a supercharged gt500 has proved to be reliable and pretty dam fun to drive.
You might want to do a search for "gt500 engine failures" before you write that check. They have had their share of them as well...but I agree fun to drive!
You sound like a true blue Chevy guy. I have checked out the GT 500 and its issues. The truth be known every performance vehicle has some sort of bug a boo Porsche included. But you’ve got to pick your path of least resistance and I wasn’t willing to take that with the motor potentially going out of the Z06 .Just my opinion. I’ve owned three vettes in 2 Shelby’s. In numerous others:. jeeps you name it and everyone of them has something
@@gws108 I do indeed lean more toward the bowtie, I always have but I am certainly not ignorant of other great makes and models. After my last reply, I was thinking the same thing...I cannot recall a performance engine that didn't have some issues, just like you said. You are also right, it all depends on what you are willing to deal with. The consensus seems to show that typically, once the head issue is addressed, the LS7 is pretty solid after that. I am OK with it. :) I love this engine. At least...for now! 😀
I believe a kidney would buy you 8 or 9 LS7's.
DroneXFun I’m not current on the street value of kidneys these days. 😉
Ok the 14’ Camaro Z/28 has the LS7 engine do they have the same problem? Or did GM fix this problem the 2nd time around??
Since I made this video I have received conflicting reports on that one. Some solid sources told me they were fixed for the Z/28 as well as crate engines, but I have still heard reports of the issue happening anyway. So it is really hard to say and I don't think we will ever know for sure and possibly, there is no single answer. My advice to be safe...consider it a possible problem and have it checked.
thank you so much!
You're welcome!
Valves are usually about redline and springs. The guides are concentric enough to run it, so that's not it, lol. If you hear ticking then failure, it broke something. Like the inner spring. This stuff is either a bad part or user error. And that's cars.
Not in this case. It is a machining/manufacturing issue. I am sure a lot of people wish it was a simple spring swap.
Mine is starting to have a slight tick, is there a chance there is piston damage or is that signs of the valve ready drop?
@@jackpaullus2643 I've come to understand that the pressed-in rocker studs pull loose, then the valve geometry binds, timing is affected and valves break. People have reported hearing noise and then complete failure. Which means engine rebuild. Stop driving the car NOW, you should have stopped before this, you are already in the RED. Pull the heads, get screw-in studs, check the guides, valves and seats. It is a manufacturer problem. Join a class action suit for compensation...Or loose the motor and/or car...On the bright side, have long tube headers installed and free flowing exhaust. Don't cheap-out on it.
@@hambone7777777 mine turned out to be a collapsed lifter
@@jackpaullus2643 yeah, and chewed lobes from moving lifters. But the broken valve/wasted head is from the pressed stud pulling, wearing the valve guide, and extending the valve into the piston. It's negligence, and a known concept going back decades. There's no excuse. Cheers
The valve broke from coming down and sit on one side of the seat first from worn out guide. The owner should be able to hear a double click valve chatter for a while before this happen. I have work on European cylinder heads for over 50 years they all have hollow stem sodium cooled exhaust valve, they all have worn out guides , never had a broken valve. They might not have as much spring pressure as the corvette, but still rev within 1000 rpm.
Thinking of getting a 110K mile C6 Z06 heads not done for 18 K, May just send it 🤷🏼♀️
At the price, might be fun. Some people have gotten lucky and had no issues. Turn up the wick on it and see what happens. 😎
Dirt cheap
I purchased a crate LS7 from GM Performance this year (2020). It seems unclear whether GM corrected the issue with their current crate engines? Does the LS7 in the Z/28 have the same problem? The engine is going into a dedicated track car that won't see a lot of miles but will do probably 15-20 track days a year. My plan was to get the heads and motor inspected and refreshed every other year, so about every 10k miles. I'm half tempted to get the heads inspected before we even put the car on the dyno.
I have been told different stories about the Z/28 since I made this video. While a source very close to the car said they did fix it, I have also seen reports of very similar failures. I don't know if it is the same issue or not. The same goes with crate engines. I think you are on the right path to check it, especially with your purposes of it.
Which LS7 did you purchase? The new wet sump LS7 from GM performance is supposed to have it fixed
@@703z06 I have just ordered the same LS7 570HP crate for my car. Here all this time later, hoping the issue has been fixed. How is yours? How many miles? What kind if rpms are you seeing? Dyno?
Hard to believe the valve guides could wear out at 10k miles. Could there have been another issue? Like “over rev”…..
Are you asking about my car specifically?
Bought a 2017 mustang that fixed my corvette engine problems
But then you traded one problem for another. 😆
How often should u get the heads fixed? My Z06 has 99k miles and it had the heads addressed by WCCH at 65k miles
The common thought it you only have to do it once if they are done right. WCCH does pretty good work but just for good measure, give them a call and see what they recommend since they did your heads.
@@InJasonsGarage yes just got off phone with em, my heads are good to go for up to .640 lift can't wait to save up to start modifying
Good content. 👍🏼
Thanks for the info. What year is your car? How many miles is on it?
Mine is a 2009 and it had around 10,000 miles on it when I did this video.
@@InJasonsGarage It’s definitely a sweet car! Thanks for the info!
how much did it cost to replace your heads and who would you recommend to do the work. I live in north east Mississippi and hard to find someone that I could trust to do it
See my other videos about this at bit.ly/ls7fixvids, I used AHP for their heads and had a great experience. For installation, I wish I could help but I don't know the shops in your area. Sorry!!
Jason I got a 2008 ZO6 with 13,000 miles on it now and I'm torn about the head issue not knowing all of all of them need to be done if there's some signs that you here before indicating when it should be done like on your car did you hear any freaking anything that made you think the valves could be warned I better check them or was it just from all the other issues you've heard from others who would you recommend to do the work and are you happy with the kit that you got?
From my research, there has been no common indication that there is an issue and pending failure. Sometimes there's noise, sometimes there isn't. I had no indication myself, I just took the advice from others. At the very least, have the heads pulled and check the valves but even then, you will likely need to have the heads redone. I have been extremely happy with the heads/cam I got from AHP. Give them a call and tell them your concerns, and tell them I sent you. They will set you up with exactly what you need and nothing more. See my other videos in my channel for unboxing, driving impressions, etc.
@@InJasonsGarage tha is so much will do ... I've been contemplating if it really needs it it's got 13,000 miles it's been baby beyond belief but I don't want to take a chance I don't think it's worth the risk myself
@@krisi.2011 That's how I look at it. You spend $45k+ on a very special and unique car, you spend a lot more money and time on top of that taking good care of it. Despite that fact that this shouldn't be an issue...it most likely is and issue and is the cost of entry to owning an LS7 powered car. So unfortunately, it is better to spend ~$2k of grand to prevent the chance of a catastrophic failure costing ~$15k if you want to play in that realm.
Any info on whether this dropped valve issue is also common on the GM crate LS3/525 or 480?
There doesn't seem to be the same type of issues typically with the LS3 based on what people are saying.
Was going to buy one until I heard about this. Decided to skip it all together and keep my current C6 z51 until I can get a C7 ZO6 or c8..
I don't know if that should stop you, the fix is as low as $1500 and labor costs, and after that...you have a no frills supercar that is very affordable by comparison.
Hi so I’m planning on buying an Ls 7 swapped rx-7 and my question for you is: how often do I need to get the heads fixed? Also is there a way to tell if the person I’m buying it from already has fixed it just by looking at it?
If you do it right, only once is the popular consensus. The easiest way to check is to ask the person you are buying from. If they say "huh?" then you might want to have them fixed. You cannot tell visually, you need to remove the heads have someone who knows what to look for see how much play there is to the valve stems, indicating out of spec valve guide wear.
Do you think GM themselves can fix the cylinder heads?
I think that GM themselves doesn't are about the LS7 any more. It is almost 8 years out of vehicle production.
I heard about the problem, ignored it, now I'm about $5000 out to fix the head, the piston, the sleeve and labor. I lucked out and the block didnt crack.
I made this video in hopes that it would prevent this from happening, so I am always sad when I hear that it does. Sounds like you got luckier than some. Hope it gets fixed cleanly and you enjoy your car more than ever.
I’ve heard that replacing the exhaust valves also alleviates the issue. Any thoughts on that?
I think it is important to have someone who knows what they are doing look at all the valves, just to be safe. It is a small piece of insurance in my opinion. See this video: th-cam.com/video/3wxM568im6I/w-d-xo.html
@@InJasonsGarage true. I am hoping to buy a z06 that has the heads replaced according to the carfax. Although that’s kinda vague, I wish I knew more about the procedure it went through lol
My '08 Z-06 has 9,800 miles. I've never heard of anyone having a problem with less than 20k miles. Can I wait another 10k miles?
Unfortunately, there is no specific number of miles that it has happened at. Some at under a thousand miles, some over 100,000 miles, some never.
A guy on this blog reported that his engine blew up at 10K miles.
Questions, I’ve heard this “head problem” exists with the LS7 engine, but does it also occur in the other model’s engines (ie, base, grand sport, Z51, etc...?)
I’m considering purchasing a Corvette within the next six months, and I haven’t heard much concerning those engines with problems like this “head issue”... Also, does this head issue carry over into the C7 model years as well...?
Thanks in advance for any answers... 👍🏾👍🏾
This specific issue is regarding the LS7. That is not to say that no other engine cannot have similar issues, but is believed to be much more common with the LS7.
Jason's Garage Thanks for responding, I greatly appreciate it...
I'm looking at a c6 z06. The said he had preventative maintenance done on it because of what happened to his buddy's ls7. The guy told me it's still the stock heads, but the valves, stems, springs etc have been changed. Is it possible to fix the valve drop issue still using the stock heads?
Yes, a lot of reputable places use a factory head but rework the guides and such to prevent or at least reduce the chances of it failing. Did he say who did the work and the parts used?
@@InJasonsGarage A shop in Michigan, Alternative auto performance. I asked him if he could find the receipt for it. He said it's been awhile but he will look for it
@@InJasonsGarage it has 9950 miles on it and I'm going to go and look at it tomorrow.
@@camonly849 I used to live not far from Alternative Auto, and I was an acquaintance of the owner Lidio. It has been a few years since I talked to him, but he is pretty much a legend in the Mustang world and expanded into LS stuff around 10 years ago. He is good guy and is known for doing good work.
@@camonly849 That's about the same number of miles mine had on it when I bought it.
2004-2008 Audi S4 BHF Timing Chain, valve guide wear, and/or cylinder bore scoring
2003-2005 Porsche 911 non-Turbo /non-GTRS IMS bearing design flaw
2006-2013 Corvette Z06 Valve Guide out of round machining flaw, design spec flaw, or material selection flaw
These are fun to catalogue.
I respectfully disagree on that whole "fun" part. It all depends on what side of the checkbook you are viewing a situation from. 😬
BMW v10 engines on M5 and M6 2005 to 2010. Rod bearing issues. Shooting rods to the moon.
Hello sir I seen your video and others I was about to buy a 13 model yesterday for a good price with 15,000 miles but the engine issues held me from doing it and my question to you would be to fix everything you’d recommend what would it cost on one of these engines for piece of mind ?
If you want an LS7 powered car, you shouldn't let this issue stop you. Just factor in the cost of having the heads fixed. Different shops have different prices but go with one that has LS7 head work experience. Check out this video: th-cam.com/video/IjZsagCk-x8/w-d-xo.html
In Jason's Garage thank you
I want one and I plan on getting the head’s done. Any tips you can recommend? I’m not afraid of buying the car, I just want to build a good reliable street car 👍🏿
100 people that’s disliked valves dropped 😂😂😂
Please tell me what year they fixed this ?
My opinion is that they didn't. Some may disagree...but others with varying years of LS7 engines will agree, and paid the price. What I still understand to this day is that there is no exact answer, so it is still and may always be a roll of the dice.
Looking at buying a 06 with 98k miles, and original heads. Runs like a top, and was recently at Chevy for a PCM issue and nothing said about any valve noise, etc.
Seller says he is aware of the valve issue, but if it’s made it 98k, it’s obviously not one of the engines affected by the wear issue.
What are your thoughts?
My 100% honest opinion...unless you got the cat on a screamin' deal and can afford to replace the engine if something goes wrong, get the valves checked by someone who knows what to look for. Even though it made it 98k miles, it doesn't mean it will go another 1k miles. It has happened with low mileage cars, high mileage cars, and everything in between. Sure, there are some that never had the issue but I'd only take that risk if you can afford it
According to GM and research 2006 Corvettes were not affected its 2008 through 2011 cars were affected by the heads.
@@InJasonsGarage2008 through 2011 ZO6 were affected. When you get in problems with this cars when you modify it that's when problems happen. I guess you think you know more than Paul Kerner the top Corvette expert in the country.
@@richardcerritelli9657 I am not claiming to know more than anyone, but I too have done my research. I also know that those who work for GM like to keep their jobs. If you ask people outside of GM, you get different answers...including people who have had the issue with their stock LS7 engines outside of the 2008-2011 range. Like this guy with his stock 2007...
th-cam.com/play/PLwpV2P5J-lOA812dx1WTgyk1k2J98T-VO.html
Good info, sticking with a c6 GS then....unless the down payment is low enuff.
Can a shop tell if the heads were fixed on a used car 37k miles before you buy?
The best way to have someone who knows what they are looking at remove the heads and check for valve guide wear.
Is it on all the cylinder heads or just a certain one?
It seems to vary.
Is this an issue with every year z06 from 06 to 13?
That seems to be the consensus, yes.
Don’t buy replacement GM heads. If you have a reputable competent aftermarket specialist like Lingenfelter rebuild your heads with superior aftermarket parts the issue won’t come back.
Good to know.
I am going to look at a 2006 Z06 tomorrow.
The owner says the heads have been "checked" but not changed.
I may just have to go ahead and figure that cost into the car.
It has about 52k miles
Th3CrypticGamer - I would take the Kelley Blue Book Value and subtract the materials and labor cost for a Lingenfelter or Katech head exchange. “Check” means absolutely nothing - even if he could show you the dealer labor paperwork on it. Unless you have a warranty with no deductible it’s all on you. Assume it’s a ticking time bomb.
@@petersouthernboy6327
Hey thanks for the reply!
I decided to pass on this particular Z06.
Thank you for the help.
Not true, the valves will still wear out due to the design of the ls7
Do you know if anyone near Maryland can get it done? I’m looking to buy a z06!
I don't have anyone that I can personally recommend in that area, but see my other videos about American Heritage Performance. I had very good luck and service with them.
Also, i would be concerned if i where you if im paying 1/3 for a new motor and install. Im sure you can oick up a used ls7 for 4k and another 1,000-2,000 for install and tuning. That way less than 10k but yes. It is still very very expensive. I’d rather pay 2K for new heads + install than a new motor lol
Sure, if you know the history of that used LS7 engine. That's a great alternative. And I agree, I'd rather just pay to have the heads addressed and reduce the chances of an issue. In fact...that's exactly what I did! See my other videos. 😎
The problem with this is he didn't say specifically what the problem was. Is it the valve spring retainer? Why does the damn thing drop?
It depends on who you ask, but it is usually said to be the valve guides but some say there's more to it than that. There's also a good article here:
katechengines.com/wp-content/uploads/TheSHOPMag_7-17.pdf
@@InJasonsGarage Thanks. Wouldn't upload but I can go to the site probably and pick it off. All the money they spend putting into that engine to get 500 horsepower and they scrimp on the valve guides. Admittedly, that just screams Chevrolet.
Did Chevy address the issue on newer crate motor?
That is not known for sure. Some say that they haven't been fixed, others say they have. I'd like to think that they have been fixed but I am definitely not the one who can confirm. I think that's kind of the problem...we just don't know for sure.
@@InJasonsGarage. Thank you for your reply.
Nope, the new LS7's are just left over Z06 engines
So is this issue strictly with the C6 Zo6?
Definitely the C6 Z06, but depending on who you ask, some say it also impacts LS7 crate engines.
Anyone have any luck with a performance shop in PA to perform this work?
Damn. That blows, I would be pissed if I had this issue, and I was worried about the supercharger on my ctsv.....lol. sucks to have a ls7
It doesn't really suck...only if it blows. :) I suppose you don't HAVE to fix it and you can take the chance. Many have gotten away with it, but quite a few have no. Once it is fixed...oh yeah, the power and torque makes it all worthwhile.
www.superchevy.com/how-to/1406-how-to-maintain-valvetrain-stability-ls7-exhaust-valves
Worth the read.... testing regarding stability using an LS7 test rig to measure stability and valve bounce at speeds up to 7900 rpm. The little shop that did the testing? Katech... yea, they probably know what they’re talking about. Hope this helps answer some questions.
I also tried to see if I could figure out how many failures had occurred in all LS7S using data on several forms. Looks to be a failure rate of 1/4 to 1/2 of 1% for all LS7 produced from what I could figure out. Not saying this is 100% correct but I think it’s close. The performance shop I use (in Garner NC) has seen 1 dropped valve but has modified hundreds of LS7s. So yes the problem is real but and no one wants to kill a $15-20K engine but it doesn’t happen with high frequency.
I actually used to live around 5 miles from Katech and I trust them. They know their stuff. I also know other people that are "up the chain" in GM performance, and the higher the chain goes, the louder the message is that it should be at least looked into if you have an LS7. It is damn near a race motor and race motors are not without needed maintenance and frequent checks. This situation reflects that. There has been nothing quite like this engine before or since, in my opinion. That is why I bought the one I did. It is a tax I am happy to pay, because it is unparalleled in performance and will become legendary, even more than it is now. I say this not because I own one, but because I researched it long ago, and my findings have not changed.
Jason's Garage - had a lifter failure in mine about 6 months after I bought it. Was told heads look fine. The motor had about 60K miles on it at that time. So motor was refreshed. I think I will do the heads in the near future for piece of mind and take advantage of the performance bump. The LS7 is pretty amazing to give the performance it does and still remain fairly civilized in the process. I went back with a LS7S cam from Texas Speed. Car makes pretty good power with stock heads (near 550 wheel). Honestly the pilot super sports can’t handle the power now until about 3 rd gear in warm weather and forget it when under 75 degrees or damp. Super fun car.
Whats a good shop in dallas area?
I wish I could tell you but I don't live in that area so I wouldn't know. I am sure if you ask around some of the forums, they can set you straight.
Hey guys hope someone can help me out, I just got a 2006 Z06 with 20k miles on it, I know about the valve drop issue and I’m prepping for it. Just wondering, when I get the American Heritage Performance headers is there anything else I should change? Maybe get checked? Trying to keep it as least expensive as I can without cutting corners. Any fellow Z06 owners have any advice to share? Thanks guys.
Least expensive? Get the AHP package 4 heads. Swap them out, done.
Got a bit more in your budget and want a little bit more power? Have them do a street port. Got some more in your budget and want even more power? Get their cam kit.
Jason's Garage thanks man I Appreciate it a lot thanks for replying going to get the heads done ASAP scared shitless that I’ll drop a valve
@@MrBrightSide784 No worries man...it is cheap insurance. Even if everyone is wrong about the valve issue...it is still worth the peace of mind...just in case. :) Let me know how it goes.
Save your money headers are a waste of time on this car you'll get no horsepower increase the only thing they're good for is giving you a headache and making your wallet lighter lighter.
How is the reliability with a set of fixed heads on the engine? I know this valve issue is the biggest problem with these engines. Thank you for the very informative video!
My opinion is that it puts the LS7 reliability to where it should have been from the factory.
Even "fixed" heads have been known to drop valves. My FED fixed heads dropped the exhaust valve last year. I was running an aftermarket cam with only .635 lift, and less than 10k miles on build, but some say this is enough lift that with the pad style rockers at full lift it puts a side load on the valves and causes premature wear to guides. Definitely upgrade to roller rockers.
Did GM correct this issue with their current LS7 crate engines?
Some say yes, some say no. I'd like to believe they did, and it would be logical to think they did. I personally haven't heard any issues about the crate engines. I know this doesn't help at all but if you happen to hear a more concrete answer, please let me know.
I just purchased one two days ago so I hope the problem has been corrected.
@@time_on_target If you don't mind, can you ask the same question to who you bought it from and let me know their answer? I am very curious.
Also...what are you putting it in?
In Jason's Garage I bought the GM performance LS7 crate from a GM dealership in WI and had it shipped to me in TX. It’s going on my 1967 mustang track car. Vorshlag here in Dallas is handling most of the build for me. 500hp in a 2600lb car should be fun.
Sounds great! I subbed to your channel to follow along.
I know a guy that happened to in his 68 Chevelle on the Power Tour.
With an LS7 or a different engine in it.
@@InJasonsGarage It was a LS7 with a tunnel ram and duel throttle bodies. I had never seen a LS style motor with a old school tunnel ram on it. I have pictures of it. BA!!
@@hotrodder5034 Sounds like it!
The stock components that come with this head or not adequate, #1 use a solid Enconel steel opposed to a hollow stem exhaust valve, #2 nurl and reem the top half of the guide to get oil stored into the guide
The stock exhaust valve is a hollow sodium filled valve (correct me if I'm wrong). What if you simply replace the valves with a solid steel valves? Will they still break and drop in the burning chamber?
Good question. The problem isn't necessarily with the valve, but the machining of the valve guide not being concentric with the valve seat. If you don't fix that, any valve swap will not be a solution. Plus, you have to consider the valvetrain weight. The LS7 can rev very high for being such a large engine thanks to a very lightweight valvetrain. Heavier valves will change the dynamics of the rest of the system.
Jason's Garage Hmm what if you swap the LS7 heads for good flowing LS3 heads? I noticed some LS7 crate engines come with LS3 heads. Here's a sample: www.mastmotorsports.com/collections/750-hp/products/ls7-427-black-label-900-supercharged-crate-engine-900hp
Are other LS engines also affected by the valve guide issue or is it just the LS7?
That engine might have LS3 heads because it is boosted and doesn't need LS7 heads. Yes, you can put LS3 heads on an LS7. You may need to check and piston to valve clearance and such and I think you would also need to replace the intake as well. You would loose a decent amount of power and you can fix the LS7 heads for less cost than the LS3 heads and intake.
All heads even after they are fixed need to be checked again..it's not a one and done
If a new crate motor is installed are you safe then
The assumption is the problem exists with all factory/OEM LS7 engines. There is no real and actual confirmation either way, so my opinion is no, not safe if staying "better safe than sorry".
Really the issue is that the valve stems are hollow so they snap really easily.
That may be an ingredient in the issue, but not the cause. If the valve seats machines properly there would be no reason for them snapping.
I can’t find anyone around here to do it for less than 5000 bucks. I want to buy one but the new z has to be fixed before I consider it.
Is that heads fixed installed and tuned? Seems on the high side. What area are you in?