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

I think I'm having valve float help!

Thread Tools
 
Search this Thread
 
Old 06-28-2012 | 05:39 PM
  #1  
Luke1834's Avatar
Thread Starter
On The Tree
 
Joined: Feb 2010
Posts: 120
Likes: 0
From: Rochester,NY
Default I think I'm having valve float help!

I have a forged bottom end with 232/236 114lsa and .615 lift cam with patriot ls6 heads when my car got to 5800 Rpms on the dyno it isntantly stoped making power.
Old 06-28-2012 | 06:30 PM
  #2  
Darkman's Avatar
TECH Addict
iTrader: (2)
 
Joined: Apr 2009
Posts: 2,167
Likes: 5
From: Spring, Texas
Default

Describe the rest of the valvetrain - i.e. what valve springs, rockers, etc.
Old 06-28-2012 | 07:47 PM
  #3  
Luke1834's Avatar
Thread Starter
On The Tree
 
Joined: Feb 2010
Posts: 120
Likes: 0
From: Rochester,NY
Default

It's got ls7 lifters comp gold 1.7 rockers hardened pushrods and it has dual spring from
The previous owner if I had to guess there probably patriot (patriot heads) it's the only used thing I used when I built this motor besides the crank . I'll post the dyno graph in a little basically climbs to 400hp as Soon as it hits 5800rpm it levels out and the line is al squiggly lol
Old 06-28-2012 | 07:55 PM
  #4  
outkast6991's Avatar
TECH Fanatic

iTrader: (34)
 
Joined: Jun 2004
Posts: 1,625
Likes: 0
From: lancaster,pa
Default

Easiest first step would be to switch back to stock rockers. After that I'd pull a couple springs and check pressures
Old 06-28-2012 | 08:10 PM
  #5  
Luke1834's Avatar
Thread Starter
On The Tree
 
Joined: Feb 2010
Posts: 120
Likes: 0
From: Rochester,NY
Default

why would i switch back to stock rockers? I had stock ones on there when it was dyno. then i put roller rockers on because the bearings were going and its exactly the same just quieter
Old 06-28-2012 | 08:35 PM
  #6  
outkast6991's Avatar
TECH Fanatic

iTrader: (34)
 
Joined: Jun 2004
Posts: 1,625
Likes: 0
From: lancaster,pa
Default

Didn't know you had the float on stockers. Aftermarket rockers are known to be heavy over the nose which will induce float. Guess its time to pull some springs
Old 06-28-2012 | 09:44 PM
  #7  
Luke1834's Avatar
Thread Starter
On The Tree
 
Joined: Feb 2010
Posts: 120
Likes: 0
From: Rochester,NY
Default

what new springs would you guys recommend this cam should make power to 6500 rpms and with the forged bottom end i wanna take it that high .
Old 06-28-2012 | 09:47 PM
  #8  
outkast6991's Avatar
TECH Fanatic

iTrader: (34)
 
Joined: Jun 2004
Posts: 1,625
Likes: 0
From: lancaster,pa
Default

Call PAC and give them your cam specs. They can get you a quality spring with the pressure you need
Old 06-28-2012 | 11:51 PM
  #9  
Havoc40's Avatar
On The Tree
 
Joined: May 2011
Posts: 157
Likes: 2
Default

Springs or lifters. Maybe a combo of both.
Old 06-29-2012 | 09:14 AM
  #10  
Luke1834's Avatar
Thread Starter
On The Tree
 
Joined: Feb 2010
Posts: 120
Likes: 0
From: Rochester,NY
Default

The lifters are like new only have maybe 200 miles on them
Old 06-29-2012 | 10:15 AM
  #11  
KRAZY K 2000 TA's Avatar
11 Second Club
iTrader: (5)
 
Joined: Mar 2003
Posts: 805
Likes: 1
From: Stockton, NY
Default

Fuel pressure at WOT? Injector size?
Old 06-29-2012 | 10:19 AM
  #12  
TurboBuick6's Avatar
TECH Enthusiast
10 Year Member
iTrader: (2)
 
Joined: Oct 2010
Posts: 678
Likes: 96
Default

A very erratic power band is valve float 90% of the time.
Old 06-29-2012 | 10:39 AM
  #13  
Luke1834's Avatar
Thread Starter
On The Tree
 
Joined: Feb 2010
Posts: 120
Likes: 0
From: Rochester,NY
Default

It has 30lb injectors , what does erratic power band mean ?
Old 06-29-2012 | 11:01 AM
  #14  
TurboBuick6's Avatar
TECH Enthusiast
10 Year Member
iTrader: (2)
 
Joined: Oct 2010
Posts: 678
Likes: 96
Default

Your power band line on the dyno gets very jagged just befor you lose your power.
Old 06-29-2012 | 02:15 PM
  #15  
dr_whigham's Avatar
The Scammer Hammer
15 Year Member
iTrader: (49)
 
Joined: Apr 2009
Posts: 6,709
Likes: 21
From: Lafayette, LA
Default

I'm guessing you need new springs, AND shimmed to within .050 of coil bind.
Old 06-29-2012 | 02:39 PM
  #16  
Luke1834's Avatar
Thread Starter
On The Tree
 
Joined: Feb 2010
Posts: 120
Likes: 0
From: Rochester,NY
Default

I think I'm just gunna get some new springs the valvtrain seems a tiny bit noisy also
Old 06-29-2012 | 04:55 PM
  #17  
Luke1834's Avatar
Thread Starter
On The Tree
 
Joined: Feb 2010
Posts: 120
Likes: 0
From: Rochester,NY
Default




that is the dyne 5 days before i switched to turbo 400
Old 06-29-2012 | 11:27 PM
  #18  
Luke1834's Avatar
Thread Starter
On The Tree
 
Joined: Feb 2010
Posts: 120
Likes: 0
From: Rochester,NY
Default

Posted dyno graph please tell if it looks ok ?
Old 07-01-2012 | 02:02 PM
  #19  
LilJayV10's Avatar
TECH Senior Member
15 Year Member
iTrader: (39)
 
Joined: Apr 2007
Posts: 9,501
Likes: 918
From: Evansville,IN
Default

Originally Posted by dr_whigham
I'm guessing you need new springs, AND shimmed to within .050 of coil bind.
This. I was going to ask what your spring height is set at.
Old 07-01-2012 | 02:03 PM
  #20  
LilJayV10's Avatar
TECH Senior Member
15 Year Member
iTrader: (39)
 
Joined: Apr 2007
Posts: 9,501
Likes: 918
From: Evansville,IN
Default

Normally when you have valve float there's a dip at the top end and then it nose dives off. It doesn't appear that yours is doing that. However your tq curve seems to be a little wavy. The local machine shop set my heads up wrong and I had horrible valve float. My dyno graph was really jagged and then dropped off.


Quick Reply: I think I'm having valve float help!



All times are GMT -5. The time now is 07:51 AM.