Are LSK Lobes Compatible with 1.8 rockers

Reply Subscribe

Thread Tools

Search this Thread

Aug 19, 2005 | 12:14 AM

DavidNJ

Thread Starter

TECH Resident

Joined: Dec 2004

Posts: 881

Likes: 1

Are LSK Lobes Compatible with 1.8 rockers

Like the 1.8 rockers that come in an LS7?

Aug 19, 2005 | 04:26 AM

DONAIMIAN

TECH Senior Member

iTrader: (18)

Joined: Jun 2002

Posts: 10,036

Likes: 0

From: NW Houston, TX

why would you need that much lift, just curious.

Aug 19, 2005 | 08:18 AM

Patrick G

LS1 Tech Administrator

iTrader: (14)

Joined: Nov 2001

Posts: 8,246

Likes: 34

From: Victoria, TX

That's some really, REALLY fast valve action. I guess with the right spring setup, anything is possible. My biggest concern is weight. The LS7 1.8 rockers might make it OK, but I'd be a little gun-shy about running the heavy Crane 1.8s with LSK lobes. Hope your heads flow well in the .700 lift range.

__________________

2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.

Aug 19, 2005 | 08:41 AM

DAPSUPRSLO

TECH Fanatic

iTrader: (14)

Joined: Dec 2003

Posts: 1,729

Likes: 0

From: Salisbury,MD

I don't think any hydraulic lifter will be able to see over 6500 rpm with that kind of lift but I could be wrong. Personally, I wouldn't try it, seems as though others are having a hard enough problem getting them to work with 1.7's. Now if you are not using hydraulic lifters then that's a whole different ball game.

Aug 19, 2005 | 09:06 AM

Patrick G

LS1 Tech Administrator

iTrader: (14)

Joined: Nov 2001

Posts: 8,246

Likes: 34

From: Victoria, TX

No problems with LSK lobes here, but I agree with you SUPRSLO, you'd probably want to get a really good lifter like Morels to work best with that kind of aggressive combination.

Aug 19, 2005 | 12:42 PM

gtovan

On The Tree

Joined: May 2005

Posts: 140

Likes: 0

The Morel hydraulic lifters are only rated to handle .670" lift so I would guess w/ LSK lobes and a 1.8/1 rocker ratio you would need a solid lifter setup, but I bet there will be some new hydraulic lifters out in the near future that can handle more lift due to the capabilities of the LS7 heads. I'm using Morel lifters on my LSK lobed cam but with a 1:7/1 ratio Jesel rocker

Aug 19, 2005 | 07:00 PM

DavidNJ

Thread Starter

TECH Resident

Joined: Dec 2004

Posts: 881

Likes: 1

Quote:

Originally Posted by stang killer

why would you need that much lift, just curious.

You want to retard the intake closing to add dynamic compression, reduce overlap for emissions, and advance exhaust opening to increase the power stroke. Best done with the most flow with the shortest duration that meets the overall performance goals. More duration and overlap comes at the expense of low speed flexibility, emissions,and fuel economy. The expression 'coming on the cam' springs to mind.

An example is the LS7 which has a 211deg intake and a 230 exhaust with 120+ separation. The best possible with emissions contraints. Since we don't have to warranty that the valve springs will last 100,000 miles for emissions, we can use a cam that the factory won't.