Generation IV Internal Engine 2005-2014 LS2 | LS3 | LS7 | L92 | LS9

L92 valve springs

Thread Tools
 
Search this Thread
 
Old Dec 30, 2007 | 11:06 PM
  #1  
WE TODD DID's Avatar
Thread Starter
TECH Fanatic
iTrader: (2)
 
Joined: Feb 2007
Posts: 1,627
Likes: 290
Default L92 valve springs

Does anyone know what the O.D. of the spring pockets can be cut to? I ordered a set of bare heads, and I need a spring with about 200lbs on the seat, and all I'm finding is a 1.55 od spring with that kind of pressure. Anyone have that sort of experience with these heads?
Reply
Old Dec 30, 2007 | 11:30 PM
  #2  
Richard@WCCH's Avatar
Banned
iTrader: (3)
 
Joined: May 2002
Posts: 1,853
Likes: 5
From: Van Nuys, CA
Default

I found a Crower 1.470" spring that worked. It had around 200lbs on the seat and a bit over 500lbs open (about .650" lift). The tough part is dealing with the retainers and minimal valve tip on the L92 valves. Check rocker/retainer/valve tip clearance very carefully before starting the engine.
Call me at the shop if you need the part numbers. I'll be in on monday for half a day.

Good luck,

Richard
Reply
Old Dec 31, 2007 | 09:36 AM
  #3  
WE TODD DID's Avatar
Thread Starter
TECH Fanatic
iTrader: (2)
 
Joined: Feb 2007
Posts: 1,627
Likes: 290
Default

Originally Posted by Richard@WCCH
I found a Crower 1.470" spring that worked. It had around 200lbs on the seat and a bit over 500lbs open (about .650" lift). The tough part is dealing with the retainers and minimal valve tip on the L92 valves. Check rocker/retainer/valve tip clearance very carefully before starting the engine.
Call me at the shop if you need the part numbers. I'll be in on monday for half a day.

Good luck,

Richard
Is 1.47 about as big as the spring pocket will go? I know on a standard ls1 head, the intake runners limit how much of a pocket you can have. I haven't personally seen a set of l92's. I found the springs, but I don't think they'll handle enough lift for my application. Something else I'm concerned with, is the installed height of the stock length valves. I was going to consider putting longer valves in the heads, but I'm afraid that if I do that, it will get the valvetrain geometry out of wack since they are non adjustable pedestal mount rockers. The more I think about it, the more problems I'm going to run into.
Reply
Old Dec 31, 2007 | 11:46 AM
  #4  
HTMtrSprt's Avatar
FormerVendor
 
Joined: Jan 2002
Posts: 173
Likes: 0
From: Mpls., MN
Default

I believe the only way to cut the spring pocket any bigger in diameter is to cut it higher on the casting and use a small shim under a larger spring seat to extend to the bottom of the stock pocket. Why do you need that much spring?
Reply
Old Dec 31, 2007 | 11:53 AM
  #5  
WE TODD DID's Avatar
Thread Starter
TECH Fanatic
iTrader: (2)
 
Joined: Feb 2007
Posts: 1,627
Likes: 290
Default

Originally Posted by HTMtrSprt
I believe the only way to cut the spring pocket any bigger in diameter is to cut it higher on the casting and use a small shim under a larger spring seat to extend to the bottom of the stock pocket. Why do you need that much spring?
Aggressive solid rollers tend to like heavier seat pressures. Running light pressure with an aggressive camshaft can break lifters, and create valve float. This whole thing I'm doing is experimental, and I just keep running into problems. On top of the spring issue, now I'm having trouble finding and adjustable offset rocker for the heads.
Reply
Old Dec 31, 2007 | 01:27 PM
  #6  
Richard@WCCH's Avatar
Banned
iTrader: (3)
 
Joined: May 2002
Posts: 1,853
Likes: 5
From: Van Nuys, CA
Default

A 1.470" spring is about as big as the stock pocket will allow. Step cutting as mentioned above is an alternative work around, except it will require a longer valve do the the decreased installed height. As you can see in the photo below there's a water jacket underneath the exhaust spring pocket. It really doesn't lend itself to being solid roller cam friendly.

Richard

Reply
Old Dec 31, 2007 | 05:10 PM
  #7  
WE TODD DID's Avatar
Thread Starter
TECH Fanatic
iTrader: (2)
 
Joined: Feb 2007
Posts: 1,627
Likes: 290
Default

Is that water jacket in the same place as an ls1 (241) head? I have an old junk head that I was working on today, and cut the spring pockets to 1.55, but didn't go any deeper than the original pocket. I drilled a few small holes around the perimeter of the intake pocket and had roughly .100 thickness to the intake runner. I didn't know about the water jacket on the exhaust side, so I guess I'll have to drill a few holes around it and see what I come up with.

Another question, how long are the stock l92 and ls1 valves? And what installed height are they in stock form? I can already see that I'm going to have to get longer valves, so I'm gonna have to figure out exactly how long. I do appreciate the assistance!
Reply
Old Dec 31, 2007 | 05:39 PM
  #8  
Richard@WCCH's Avatar
Banned
iTrader: (3)
 
Joined: May 2002
Posts: 1,853
Likes: 5
From: Van Nuys, CA
Default

Your going to find the exhaust spring pad very thin after machining for a 1.550" pocket. In fact you may break through during the machining process. All these factory castings are a thin wall design.
The factory stock valve lengths are 4.885" on the intake side and 4.920" on the exhaust side. You're going to need somewhere a least a .100" long valve. You might try looking at LS7 valves as they're longer overall and also have a longer tip length. Of course you'll need some aftermarket rocker system to work with the longer valves.
Just an idea........

Richard
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo




All times are GMT -5. The time now is 08:53 AM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE