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

How much power will a 4.8 hold?

Thread Tools
 
Search this Thread
 
Old 07-25-2003, 06:29 PM
  #1  
Teching In
Thread Starter
 
TurboCrazed's Avatar
 
Join Date: Jul 2003
Location: St.Louis
Posts: 8
Likes: 0
Received 0 Likes on 0 Posts
Default How much power will a 4.8 hold?

Just wondering how much power a 4.8 will hold up to before it breaks. Does anyone know where I can get the full specs of the 4.8? What kind on internals are in them, forged? I have a freind with a 4.8 and I am building a custom turbo setup for it and Im just wanting to know how hard I can push it. Thanks for any info!!!
Old 07-25-2003, 06:32 PM
  #2  
Banned
 
Join Date: Sep 2002
Location: Azle/Saginaw, Tx
Posts: 5,581
Likes: 0
Received 0 Likes on 0 Posts
Default Re: How much power will a 4.8 hold?

texasterminator is the only person i know of that's blown one up on prolonged supercharging. FAST4.8 blew one up(i have it now) but that was a dry nitrous shot blow up. i'm thinking of building a forged heads/cam/nitrous 4.8 for a different project not a truck.
Old 07-25-2003, 06:44 PM
  #3  
Teching In
Thread Starter
 
TurboCrazed's Avatar
 
Join Date: Jul 2003
Location: St.Louis
Posts: 8
Likes: 0
Received 0 Likes on 0 Posts
Default Re: How much power will a 4.8 hold?

So....how much power do they hold and what kind of internals?
Old 07-25-2003, 06:53 PM
  #4  
Adkoonerstrator
iTrader: (4)
 
XLR8NSS's Avatar
 
Join Date: Nov 2001
Location: Deep in the seedy underworld of Koonerville
Posts: 21,436
Likes: 0
Received 3 Likes on 2 Posts
Default Re: How much power will a 4.8 hold?

No forged internals. I think the pistons are cast and the rods are powdered metal(pretty strong).

As far as power capacity, the crank and rods should be fine for quite a bit 500+??. I don't know if anyone has destroyed a 4.8 from just power output, more than likely tuning was more a factor. The pistons will take quite a bit as long as they don't see any detonation.
Old 07-25-2003, 06:57 PM
  #5  
Adkoonerstrator
iTrader: (4)
 
XLR8NSS's Avatar
 
Join Date: Nov 2001
Location: Deep in the seedy underworld of Koonerville
Posts: 21,436
Likes: 0
Received 3 Likes on 2 Posts
Default Re: How much power will a 4.8 hold?

Here is a site with a little info on the 4.8L.

Basically just the bore and stroke.

http://www.gm.com/automotive/gmpower...ehicle/lr4.htm
Old 07-25-2003, 08:09 PM
  #6  
Teching In
Thread Starter
 
TurboCrazed's Avatar
 
Join Date: Jul 2003
Location: St.Louis
Posts: 8
Likes: 0
Received 0 Likes on 0 Posts
Default Re: How much power will a 4.8 hold?

Sweet man thanks!!!!
Old 07-25-2003, 08:11 PM
  #7  
TECH Senior Member
iTrader: (2)
 
GREGGO's Avatar
 
Join Date: Dec 2001
Location: League City, Texas
Posts: 9,101
Likes: 0
Received 0 Likes on 0 Posts
Default Re: How much power will a 4.8 hold?

Ther was a guy that did a heads and cam with prochargert hat was in the 370 range and it died on the pistons I believe. Texas Terminator maybe?

Mine blew up at about 350hp due to a lean n2o shot.
Old 07-25-2003, 08:23 PM
  #8  
Teching In
Thread Starter
 
TurboCrazed's Avatar
 
Join Date: Jul 2003
Location: St.Louis
Posts: 8
Likes: 0
Received 0 Likes on 0 Posts
Default Re: How much power will a 4.8 hold?

Yea,
Im fairly good with tuning if I got a good system to work with. I plan on using an intercooler and Alky/Water injection on it to keep from burning up the pistons.
I think that I could get 425 RWHP no problem.

Also,
Are the fuel systems on the trucks like an LS1? With the in-tank regulator?
Old 07-25-2003, 08:27 PM
  #9  
Adkoonerstrator
iTrader: (4)
 
XLR8NSS's Avatar
 
Join Date: Nov 2001
Location: Deep in the seedy underworld of Koonerville
Posts: 21,436
Likes: 0
Received 3 Likes on 2 Posts
Default Re: How much power will a 4.8 hold?

The fuel systems are not the same. The regulator is on the side of the drivers side fuel rail and is manifold referenced. Evidently it doesn't raise pressure 1:1 under boost but, does raise it some. I think parish8 said it was like .5psi fuel/1psi boost. Fuel pressure at idle is like 50psi and rises to 59psi at 0 manifold vacuum.

We actually have a nicer fuel system than the Fbodys except for the crappy little injectors GM stuck us with.

An intercooler and water/alky will be AWESOME.
Old 07-25-2003, 08:40 PM
  #10  
single digit dreamer
iTrader: (6)
 
parish8's Avatar
 
Join Date: Mar 2002
Location: omaha ne
Posts: 9,743
Likes: 0
Received 2 Likes on 2 Posts
Default Re: How much power will a 4.8 hold?

my base presure was right at 58psi and with 8-9psi of boost i got up to ~62psi. better than nothing.


Quick Reply: How much power will a 4.8 hold?



All times are GMT -5. The time now is 12:42 PM.