GM Engine & Exhaust Performance EFI | GEN I/GEN II/GEN III/GEN IV Engines |Small Block | Big Block |

My Lsa Is At 116 So That Hurts My Topend

Thread Tools
 
Search this Thread
 
Old 02-15-2006 | 08:04 PM
  #1  
phasemaster1's Avatar
Thread Starter
TECH Fanatic
iTrader: (11)
 
Joined: Aug 2005
Posts: 1,416
Likes: 0
From: florida
Default My Lsa Is At 116 So That Hurts My Topend

Quick Question I'm Going To Install Oldman Cam From Thunder But I Read That Because My Lsa Is 116 Topend Going To Be Hurt. Well Dont The Truck Intakes Hurt At Top Anyway Please Help I'm Confused And Broke So Cam Is Going In No Matter What.
Old 02-15-2006 | 08:52 PM
  #2  
TurboGibbs's Avatar
TECH Senior Member
iTrader: (6)
 
Joined: Jul 2005
Posts: 5,257
Likes: 0
From: Decatur, AL
Default

your top end will still be better than stock but yes, a 114 lsep would give you more top end but less down low.
Old 02-16-2006 | 03:21 PM
  #3  
98TAauto's Avatar
TECH Veteran
iTrader: (2)
 
Joined: Nov 2001
Posts: 4,316
Likes: 0
From: Warsaw, Va
Default

it would still be better than stock, but i thought a 116 would have slightly more topend but it depends on the grind also. A 116 would peak higher than a 114 depending on the Duration

i would think you would loose more low end with the 116 than 114 though. Only plus to a 116 is that it will idle like stock or better than stock
Old 02-16-2006 | 05:52 PM
  #4  
FarmerBeau's Avatar
Sexy Party Mod
iTrader: (2)
 
Joined: Mar 2005
Posts: 5,429
Likes: 0
From: Spring, Texas
Default

Originally Posted by 98TAauto
it would still be better than stock, but i thought a 116 would have slightly more topend but it depends on the grind also. A 116 would peak higher than a 114 depending on the Duration

i would think you would loose more low end with the 116 than 114 though. Only plus to a 116 is that it will idle like stock or better than stock
Thats what i thought as well. I thought with the raising of the lsa then the powerband would move up as well.
Old 02-16-2006 | 07:06 PM
  #5  
phasemaster1's Avatar
Thread Starter
TECH Fanatic
iTrader: (11)
 
Joined: Aug 2005
Posts: 1,416
Likes: 0
From: florida
Default

I Dont Know What To Expect Everbody Is Doing The Tr220 These Are The Cam Specs 215/221 .605/.532 116lsa. Well I Can Change Later If Not Happy It Will Be A Lot Cheaper.
Old 02-16-2006 | 08:44 PM
  #6  
TurboGibbs's Avatar
TECH Senior Member
iTrader: (6)
 
Joined: Jul 2005
Posts: 5,257
Likes: 0
From: Decatur, AL
Default

The wider the lobe sep the less overlap. The less overlap allows your engine to run more effieciently at low end power band. Idle is the bottom of the low end. That is why a wider lobe sep gives you a smoother idle. The wider lobe sep also widens the power band but will not peak as much power as a more narrow lsa. The more narrow the lsa the tighter your power band is and the more peak hp you will produce. Duration and intake lobe center line determine where the peak power is produced and how much of it. The more duration you have the more overlap and the higher the power band will be.
Circle track engines often have LSA as narrow as 98*. These engines will only operate in a ~1500rpm powerband so all they are interested in is building peak power in that area. If you watch a NASCAR race and when a car leaves the pits it has to drop the clutch at 5K+ to build enough power to turn the tires over and move out of it's own tracks. The LSA is so tight that they don't build any power until 5k+. This is why they often kill the engine trying to leave the pits. The huge duration they run affect this as well.

Last edited by mjhoward; 02-16-2006 at 08:49 PM.
Old 02-17-2006 | 04:12 AM
  #7  
ktmrider's Avatar
TECH Fanatic
 
Joined: Apr 2003
Posts: 1,107
Likes: 2
From: Albuquerque, NM
Default

What MJH said. The narrower or small LSA causes a scavenging effect in the cylinder due to the intake valve opening before the exhaust closes. The exiting gases help "suck" additional fuel charge into the cylinder. This is good for increased top end but reeely bad for emissions. You also want a bigger LSA for forced induction or N2O applications.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
wickedRCSB
GM Parts Classifieds
2
10-10-2015 10:29 PM
03sierraslt
GM Engine & Exhaust Performance
14
10-09-2015 06:53 AM
shootermwc
GM Parts Classifieds
2
10-08-2015 02:45 PM
Jake75
GM Parts Classifieds
5
10-02-2015 03:28 PM
slowec
FORCED INDUCTION
11
09-25-2015 12:20 PM




All times are GMT -5. The time now is 02:56 PM.