FORCED INDUCTION Turbos | Superchargers | Intercoolers | H2O/Meth Injection
Sponsored by:
Sponsored by:

Should I put 6L heads on my radixed 4.8?

Old Oct 12, 2005 | 01:27 PM
  #1  
TurboGibbs's Avatar
Thread Starter
TECH Senior Member
iTrader: (6)
 
Joined: Jul 2005
Posts: 5,257
Likes: 0
From: Decatur, AL
Default Should I put 6L heads on my radixed 4.8?

I have come across a set of 6.0 heads and from what I can figure my compression would drop from 9.5 to 8.5. Do you think that the little bit of improved head flow and the lower compression would be worth it? That would allow me to run some serious timing, but would that overcome the loss of compression? I could pulley it down to 2.75 safely then as well. What do you guys think. Has anyone done any low compression lsx with a radix? And if so what did you find?
Reply
Old Oct 12, 2005 | 03:08 PM
  #2  
Yellowsierra's Avatar
TECH Fanatic
iTrader: (7)
 
Joined: Mar 2004
Posts: 1,028
Likes: 0
From: NC
Default

Originally Posted by mjhoward
I have come across a set of 6.0 heads and from what I can figure my compression would drop from 9.5 to 8.5. Do you think that the little bit of improved head flow and the lower compression would be worth it? That would allow me to run some serious timing, but would that overcome the loss of compression? I could pulley it down to 2.75 safely then as well. What do you guys think. Has anyone done any low compression lsx with a radix? And if so what did you find?

I dont think I would put the 6.0 heads on there because like you said it will probley lower your compression to 8.5-1. Thats usally a good thing with forced induction but the radix will only put out some much boost. I bet you would probley lose 2 psi by lowering the compression that much. I think I would stick with the 5.3 heads and just get them ported and maybe bigger valves put in. Thats just my 2 cents worth I might be totally wrong just trying to help you out.

lator

Yellow
Reply
Old Oct 12, 2005 | 03:20 PM
  #3  
zippy's Avatar
TECH Veteran
 
Joined: Sep 2003
Posts: 4,534
Likes: 3
From: Las Vegas, NV
Default

you haven't reached the point yet where your current compression is too much. you won't get there with the radix. seems like a losing battle.
Reply
Old Oct 12, 2005 | 03:35 PM
  #4  
8ALTNG's Avatar
TECH Junkie
iTrader: (1)
 
Joined: Aug 2003
Posts: 3,647
Likes: 1
From: Methuen, MA
Default

I would say go with a set of LS1 heads. They will lower the compression alittle and I know for a fact that they make good power with a 4.8/radix combo.
Reply
Old Oct 12, 2005 | 03:52 PM
  #5  
TurboGibbs's Avatar
Thread Starter
TECH Senior Member
iTrader: (6)
 
Joined: Jul 2005
Posts: 5,257
Likes: 0
From: Decatur, AL
Default

I may save them for a 6L or 408 build. I do know in every engine build I've been involed in, they like as much timing as you can throw at it until you have detonation problems. I've run motors as high as 55 degree total timing because it would run faster the more I would throw to it. They were N/A of course. Appreciate your input.
Reply
Old Oct 12, 2005 | 10:02 PM
  #6  
Slowhawk's Avatar
LS1Tech Sponsor
iTrader: (11)
 
Joined: Nov 2001
Posts: 14,771
Likes: 0
From: Bridgewater,Ma
Default

You do not want to put 6.0 heads on a 4.8 motor. You would have to use 6.0 gaskets and the 4.8 bore is just too small.Easy way to get detination.
Reply
Old Oct 12, 2005 | 10:02 PM
  #7  
Slowhawk's Avatar
LS1Tech Sponsor
iTrader: (11)
 
Joined: Nov 2001
Posts: 14,771
Likes: 0
From: Bridgewater,Ma
Default

You do not want to put 6.0 heads on a 4.8 motor. You would have to use 6.0 gaskets and the 4.8 bore is just too small.Easy way to get detination.
Reply
Old Oct 12, 2005 | 10:12 PM
  #8  
8ALTNG's Avatar
TECH Junkie
iTrader: (1)
 
Joined: Aug 2003
Posts: 3,647
Likes: 1
From: Methuen, MA
Default

Nice double post Don
Reply
Old Oct 13, 2005 | 12:02 AM
  #9  
vanillagorilla's Avatar
TECH Veteran
iTrader: (1)
 
Joined: Apr 2004
Posts: 4,038
Likes: 1
From: Arizona Bay
Default

F8L put 317's on his 5.3 and was able to run 13-14psi. It was a turbo, but that just shows you the potential. I'm eventually going to this to mine, but I need a fuel system and better tranny first.
Reply
Old Oct 13, 2005 | 03:08 AM
  #10  
1slow01Z71's Avatar
Tin Foil Hat Wearin' Fool
iTrader: (36)
 
Joined: Oct 2004
Posts: 23,204
Likes: 4
From: Austin, TX
Default

Wonder where you get them heads from.

Get them shaved a bit to bump compression up to 9:1, port them yourself, and have a better flowing head and being able to pulley down even further.
Reply

Thread Tools
Search this Thread

All times are GMT -5. The time now is 09:27 AM.