Best valve springs?

[Geotrash]

I'm in the fortunate position of having both of our Denali's here in Richmond, VA for a few months (normally we leave one in Colorado for when we're there every month, but with COVID we're not flying back and forth). So I'm going to take this opportunity to do some heavy-ish maintenance work to both of them since we only need one in service at any given time right now.

One of the things I'm considering is putting in new valve springs on both, understanding that it's a weak spot on these engines. I seem to remember a thread somewhere where someone recommended a specific (non-GM) brand of valve springs that are bullet-proof, but try as I might, I can't find it. Anyone know or have a good recommendation for them?

Denali #1 is a 2007 with the L92 and 208K miles (no AFM)
Denali #2 is a 2012 with the L94 and 117K miles, and an AFM disabler.

I'm also open to other ideas for things I should probably do, since both are used for cross-country drives and towing sometimes, and I like keeping my stuff tiptop. No other signs of impending trouble at the moment, thankfully, except as noted below.

Some things I've done already:

• H3 motor mounts on the '07
• Gruvenparts billet heater core tee mod on both
• All new belts and hoses on both, including new bearings on all idler pulleys.
• New OEM fuel pump on the '07 due to high fuel pressure and related codes. Solved.
• New alternator on the '07
• All new fluids on both (engine oil, trans, diffs, TC, brakes and PS)
• All new front suspension on the '07 with all Moog parts. Drives like new again.
• Planning to replace the rear autoride shocks and airbags on the '12 with OEM. One of them is leaking fluid. Pump seems to be working fine, no air leaks noted.
• Considering a new cam phaser assembly on the '07, given the mileage. Thoughts?

I'm reasonably handy and comfortable doing even heavy maintenance work. I've successfully rebuilt a ZF automatic transmission from a BMW 740iL on the bench in my workshop, have done timing chain work on the same car, cylinder head work on an Acura Legend, driveline work on Land Rovers, etc.

Thanks for your consideration, guys!

Cheers,
Dave

 

[Chert_Detective]

I haven't heard much about valve springs failing, not saying it hasn't happened though. What is common however on those two engines are lifters. The AFM lifters as I'm sure you're already aware are notorious for failures. The 2012 will no doubt have them. The 07/08 L92s depending on when the engine was built will have them as well, but the AFM feature itself is not active.

Check the valley cover of your 07, if it is the same as your 12 then it too has the AFM lifters. @swathdiver can double check me on that as I'm not 100% sure if they still put the AFM valley cover on the 07s. I know on my 08 it had conventional lifters and valley cover as 08s did not even have the AFM hardware like 07s.


Full circle.. lol. Be more concerned with lifters than valvesprings.

 

[wjburken]

‘07 Denali’s did not have the VLOM valley cover.

I had two valve springs fail on my ‘07. Got lucky and no damage to motor.

Had two lifters have their rollers lock up and take out the cam. 1st one resulted in a crate motor. The 2nd just a new cam and lifters.

 

[Chert_Detective]

‘07 Denali’s did not have the VLOM valley cover.

I had two valve springs fail on my ‘07. Got lucky and no damage to motor.

Had two lifters have their rollers lock up and take out the cam. 1st one resulted in a crate motor. The 2nd just a new cam and lifters.

That's wild. How many miles were on it when you had the spring failure? Just a lifetime of regular driving?

 

[wjburken]

That's wild. How many miles were on it when you had the spring failure? Just a lifetime of regular driving?

At about 120K and 135K.

Bought it off my employer at 100K knowing it was well maintained.

 

[swathdiver]

I haven't heard much about valve springs failing, not saying it hasn't happened though. What is common however on those two engines are lifters. The AFM lifters as I'm sure you're already aware are notorious for failures. The 2012 will no doubt have them. The 07/08 L92s depending on when the engine was built will have them as well, but the AFM feature itself is not active.

Check the valley cover of your 07, if it is the same as your 12 then it too has the AFM lifters. @swathdiver can double check me on that as I'm not 100% sure if they still put the AFM valley cover on the 07s. I know on my 08 it had conventional lifters and valley cover as 08s did not even have the AFM hardware like 07s.


Full circle.. lol. Be more concerned with lifters than valvesprings.

The very earliest L92s, those manufactured in or before April of 2005 have the AFM hardware but it was not active in the tune. The first L92s went on sale in the Yukon Denalis in December 2005 (MY2007) and the Escalades followed suit in January 2006. This was limited to just a few hundred units and we've seen just a few on here and over at Performance Trucks.

As for valve springs, every year we get 2-3 people coming on here with 6.2s with a broken valve spring, usually on cylinder #8 but not exclusively and these are usually 2007-2008 Denalis though other years have also been represented. One wonders if this is due to metal fatigue due to age? We rarely hear of this issue with the 5.3s, their camshafts have less lift by about .018 to .037 inches.

 

[iamdub]

I can't suggest any particular valve spring other than new OEM ones. Which, I wouldn't be surprised if they all come with the "LS6/LS3" spring as standard equipment.

Don't forget new valve seals while your're at it.

 

[Mechanic421]

Vinci performance

 

[Geotrash]

Thanks for the replies, all.

James, I'm relieved to know it doesn't seem that frequent in your considerable experience here.

Chris, I believe you're correct. That said, GM just released a bulletin for newer Corvettes to fix an issue of breaking valve springs from engines manufactured this year, and valve springs seem to be more of an issue with 2015-2020 6.2s in general as well. I'm concerned that there could be a problem with valve springs manufactured by GM's suppliers in the last several years, but especially in the last several months, hence the desire to buy a different brand, as long as its reputation is sound. Could be a total waste of time, but it's an irrational peace of mind thing.

David, I'll check out Vinci. Thanks for the tip.

Best,
Dave

 

[Geotrash]

Vinci performance

Checked out their site. Makes me want to install a new cam in the 2012 for a proper DoD delete, complete with new lifters, pushrods, springs, rockers, timing chain/sprockets and seals.

 

[Mechanic421]

I have stage 2 hi lift cam,cathedral port heads duel 660 springs I did use summit racing.105 wall push rods and bronze trunnions. Sounds nice at 5800!forgot Vinci matched lifters . I did have a issue with one lifter not compressing but Roger Vinci handles customer service himself and had one out quickly.

 

[avalonandl]

Check your rocker arm while you are in there. They may have the trunions that lose needle bearings. Summit is good for parts.

 

[Rocket Man]

Checked out their site. Makes me want to install a new cam in the 2012 for a proper DoD delete, complete with new lifters, pushrods, springs, rockers, timing chain/sprockets and seals.

I would do that for sure. That would be the only way for me to have peace of mind. I have nothing but the best to say about VHP. Roger Vinci is an awesome guy who will go out of the way to make sure you’re taken care of and answer questions. You should consider a more aggressive cam while you’re doing it- that’s cheap HP.

 

[Geotrash]

I would do that for sure. That would be the only way for me to have peace of mind. I have nothing but the best to say about VHP. Roger Vinci is an awesome guy who will go out of the way to make sure you’re taken care of and answer questions. You should consider a more aggressive cam while you’re doing it- that’s cheap HP.

Roger has a real nice "towing cam" on his site, too. Prices are attractive and the springs he sells for the kit are duals - cheap insurance. Gonna work up a parts list for the job and will share it back here when I'm through. I'll have to budget in a tune as well. Will probably tackle that oil pump o-ring while I'm in there before it fails. Should make a real nice project over a couple of weekends in December. Thanks for weighing in.

 

[Dantheman1540]

Roger has a real nice "towing cam" on his site, too. Prices are attractive and the springs he sells for the kit are doubles - cheap insurance. Gonna work up a parts list for the job and will share it back here when I'm through. I'll have to budget in a tune as well. Will probably tackle that oil pump o-ring while I'm in there before it fails. Should make a real nice project over a couple of weekends in December. Thanks for weighing in.

I highly suggest dual springs no matter how mild the cam is.

 

[Geotrash]

I highly suggest dual springs no matter how mild the cam is.

Scary pics! Excellent advice - thanks to this thread, dual springs are the way I will go.

 

[Dantheman1540]

Scary pics! Excellent advice - thanks to this thread, dual springs are the way I will go.

I know Vinci is a big fan of lower lift cams to prevent this but dual springs have no downside that I know of besides a slightly higher initial cost. If I had dual springs from the start I would have just saved myself over $1,000.


Also Vinci has such awesome customer service!

 

[iamdub]

Checked out their site. Makes me want to install a new cam in the 2012 for a proper DoD delete, complete with new lifters, pushrods, springs, rockers, timing chain/sprockets and seals.

Well, you ARE after peace of mind...


Since you'll have the heads off, may I suggest a shave to get the chambers down to 65 or even 64 CC and some thinner head gaskets to net .035" quench?

 

[Dantheman1540]

Well, you ARE after peace of mind...


Since you'll have the heads off, may I suggest a shave to get the chambers down to 65 or even 64 CC and some thinner head gaskets to net .035" quench?

Gatoraid quenches my thirst well, But I've never tried a head gasket-metal shaving cocktail

 

[iamdub]

Gatoraid quenches my thirst well, But I've never tried a head gasket-metal shaving cocktail

Works great! Both build compression but shorter quench height helps to stave off detonation. I did both to mine, but the guy only took my chambers to 65cc. I would've rather had then at 64cc.