Generation III Internal Engine 1997-2006 LS1 | LS6
Sponsored by:
Sponsored by:

Max Lift for the LS1

Old 10-12-2006, 03:49 PM
  #1  
11 Second Club
Thread Starter
iTrader: (1)
 
Doc GTO's Avatar
 
Join Date: Jun 2004
Location: Ocala, FL
Posts: 61
Likes: 0
Received 0 Likes on 0 Posts

Default Max Lift for the LS1

I tried searching but it gives me a server busy message so I figured I'd just ask you pros in the forum.

What is the max lift for a stock LS1 head? I have a FMS F10-12 with 228/228 - .575/.575 and wanted to go with Harland Sharp 1.8 roller rockers. I've upgraded the valvetrain when I did the cam install but with these rockers it will bring the lift to .609. Will I have enough piston to valve clearance and will the rockers clear the valve covers or do I need to get spacers?

Thanks for the help in advance!
Old 10-12-2006, 05:45 PM
  #2  
TECH Fanatic
 
ringram's Avatar
 
Join Date: Aug 2005
Location: Sunny London, UK
Posts: 1,690
Likes: 0
Received 0 Likes on 0 Posts

Default

Clay it. Also depends on how you time the cam obviously.
Old 10-12-2006, 05:50 PM
  #3  
Banned
iTrader: (2)
 
SStrokerAce's Avatar
 
Join Date: Mar 2002
Location: NY
Posts: 2,344
Likes: 0
Received 1 Like on 1 Post
Default

Do you want to know how far you can open the valve? It has to do with a lot of things, the first being coil bind of the springs, if you try and exceed that it will cause a big mess.

Bret
Old 10-12-2006, 07:41 PM
  #4  
11 Second Club
Thread Starter
iTrader: (1)
 
Doc GTO's Avatar
 
Join Date: Jun 2004
Location: Ocala, FL
Posts: 61
Likes: 0
Received 0 Likes on 0 Posts

Default

Lets say I was going to put in a cam in a stock LS1, what would be the max lift cam that would fit without changing the heads (i.e .600, .610 ect . . .) My springs are good for .625 so bind shouldn't be an issue. I'm still pretty new at this stuff in American muscle so excuse the ignorance. I just want to make sure I can install the roller rockers and not destroy anything. The rockers will increase lift to .609 on both sides.
Old 10-12-2006, 08:17 PM
  #5  
On The Tree
iTrader: (3)
 
99 bad aSS's Avatar
 
Join Date: Jun 2005
Location: San antonio
Posts: 167
Likes: 0
Received 0 Likes on 0 Posts
Default

If you install the cam strait up I don't see you having any problems. There are cams with .040 more valve lift out there for stock motors.
Old 10-12-2006, 09:08 PM
  #6  
12 Second Club
iTrader: (24)
 
Demon_Speeding's Avatar
 
Join Date: Jan 2005
Location: Olathe, KS
Posts: 562
Likes: 0
Received 0 Likes on 0 Posts
Default

You should also check with the FMS. Some of the cam manufacturers out there do not recommend running higher ratio rockers due to the aggressive ramp rates of certain camshafts. In theory you would be good with that amount of lift though. There are quite a few running the T-rex and Magic Stick cams with stock heads/pistons. Some have higher lifts, but they've flycut their pistons for them. I really think the best bet would be to talk to FMS first.
Old 10-12-2006, 09:10 PM
  #7  
TECH Veteran
iTrader: (21)
 
Beast96Z's Avatar
 
Join Date: Apr 2003
Location: Shreveport, LA
Posts: 4,049
Likes: 0
Received 3 Likes on 2 Posts

Default

Lots more than lift determine if the cam will "fit". It's all in the cams valve events and where they are in relation to the piston. X cam with .600" lift might not fit where as Y cam with .650" lift will. However, with the cam you have, i don't think P/V will be of concern with the .609" lift. I highly doubt lift will play any concern in wether or not the rockers will fit under the covers either. As with all cases, it's best to throw a piece of clay on top of the piston and roll it over. You can never be to safe.
Old 10-12-2006, 09:12 PM
  #8  
11 Second Club
Thread Starter
iTrader: (1)
 
Doc GTO's Avatar
 
Join Date: Jun 2004
Location: Ocala, FL
Posts: 61
Likes: 0
Received 0 Likes on 0 Posts

Default

Thanks for the info guys. Now I know what "clay it" means as well!
Old 10-12-2006, 09:13 PM
  #9  
Staging Lane
iTrader: (1)
 
02NITROUSLS1's Avatar
 
Join Date: Jun 2006
Location: Knoxville Tennessee
Posts: 68
Likes: 0
Received 0 Likes on 0 Posts

Default

I have a MS4 and the cam card reads 651 Intake & 609 Exhaust. I have not had any problems with mine.
Old 10-12-2006, 09:32 PM
  #10  
TECH Fanatic
iTrader: (118)
 
snake charmer's Avatar
 
Join Date: Sep 2004
Location: The south
Posts: 1,512
Likes: 0
Received 1 Like on 1 Post

Default

Is anyone running 1.8s on a big cam like a ms3 , 4 or trex ?
Old 10-19-2006, 10:03 AM
  #11  
Launching!
iTrader: (2)
 
BLUEBALLS ZZ's Avatar
 
Join Date: Dec 2001
Location: HOLLY SPRINGS, NC
Posts: 232
Likes: 0
Received 1 Like on 1 Post

Default

Originally Posted by snake charmer
Is anyone running 1.8s on a big cam like a ms3 , 4 or trex ?
great question
Old 10-19-2006, 12:17 PM
  #12  
TECH Fanatic
iTrader: (1)
 
lilbuddy1587's Avatar
 
Join Date: May 2004
Location: Mesa, Arizona
Posts: 1,691
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by BLUEBALLS ZZ
great question
Thats actually a ridiculous question because it wouldn't be necessary.
Old 10-25-2006, 04:25 PM
  #13  
Launching!
iTrader: (2)
 
BLUEBALLS ZZ's Avatar
 
Join Date: Dec 2001
Location: HOLLY SPRINGS, NC
Posts: 232
Likes: 0
Received 1 Like on 1 Post

Default

Originally Posted by lilbuddy1587
Thats actually a ridiculous question because it wouldn't be necessary.
lmao. well, then explain it since you know so much
Old 10-25-2006, 04:43 PM
  #14  
10 Second Club
iTrader: (14)
 
Cop Car's Avatar
 
Join Date: Jul 2005
Location: Indy
Posts: 2,520
Likes: 0
Received 0 Likes on 0 Posts

Default

its not about advertised lift, or lift with your rocker arms.. its about the cam specs, if the valve is heald open for a really long time its going to hit, even if it has stock lift specs. with a 228 i personaly dont think youd have an issue, but then again im not a cam god. im just going by the fact that a 242 duration cam with more than .600 lift dosent need flycutting
Old 10-25-2006, 04:59 PM
  #15  
On The Tree
iTrader: (12)
 
BryanJohnson's Avatar
 
Join Date: Jan 2006
Location: Wichita Falls
Posts: 177
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by Beast96Z
Lots more than lift determine if the cam will "fit". It's all in the cams valve events and where they are in relation to the piston. X cam with .600" lift might not fit where as Y cam with .650" lift will. However, with the cam you have, i don't think P/V will be of concern with the .609" lift. I highly doubt lift will play any concern in wether or not the rockers will fit under the covers either. As with all cases, it's best to throw a piece of clay on top of the piston and roll it over. You can never be to safe.
some larger bodied aftermarket rocker arms require grinding on the valve cover or using a spacer regardless of the lift.
Old 10-25-2006, 07:24 PM
  #16  
Launching!
iTrader: (2)
 
BLUEBALLS ZZ's Avatar
 
Join Date: Dec 2001
Location: HOLLY SPRINGS, NC
Posts: 232
Likes: 0
Received 1 Like on 1 Post

Default

thats not really going to be an issue if you have -2 vavle reliefs. from what i undersand. teh comp guys and performace guys worry more about valve float because of the high ramp rates. saying that. i seen big block chevy valve spring on a 750 lift and they uses 1.8 shaft mounted rockers.
Old 10-25-2006, 08:12 PM
  #17  
TECH Addict
iTrader: (3)
 
BlackHawk T/A's Avatar
 
Join Date: Nov 2005
Location: Lincoln, NE
Posts: 2,869
Likes: 0
Received 0 Likes on 0 Posts
Default

Thunder Racing says:

"Due to the fast ramp rate of this camshaft, the use of 1.8 rockers is not recommended."

I'd say anything with fast ramp rates, like XE-R lobes, stick with a stock rocker ratio.


Thread Tools
Search this Thread
Quick Reply: Max Lift for the LS1



All times are GMT -5. The time now is 12:18 AM.