NA 4.8 potential
NA 4.8 potential Just wondering what kind of power a 4.8 could potentially make with a street-able head/cam/intake setup?
I've got an 03 reg cab short bed silverado that could use some pep. I don't plan on ever racing, or hoping that its fast, but I don't want to invest a bunch of money if it won't break 400whp.
Thanks
I've got an 03 reg cab short bed silverado that could use some pep. I don't plan on ever racing, or hoping that its fast, but I don't want to invest a bunch of money if it won't break 400whp.
Thanks
Ive seen trucks with 4.8's dyno around 300rwhp with bolt ons and a tune. I think they have potental but nobody wants to put money in a 4.8 when you can build a 5.3 for around the same $$.
http://www.hotrod.com/techarticles/h...g_bang_theory/
hot rod made 451 flywheel hp on an engine dyno. would probably be 370-380 whp on a chassis dyno with a 6 speed/10 bolt F-body.
not many people build 4.8s for NA power.
hot rod made 451 flywheel hp on an engine dyno. would probably be 370-380 whp on a chassis dyno with a 6 speed/10 bolt F-body.
not many people build 4.8s for NA power.
TECH Junkie
Joined: Dec 2005
Posts: 3,092
Likes: 11
As you probably know a lot of people are just turbo charging the 4.8L as they are plentiful without much demand and therefore cheap to buy. Good horsepower can be made with a turbo on the 4.8L. I know you are asking N/A but I am just throwing it out there for conversation.
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As you probably know a lot of people are just turbo charging the 4.8L as they are plentiful without much demand and therefore cheap to buy. Good horsepower can be made with a turbo on the 4.8L. I know you are asking N/A but I am just throwing it out there for conversation.
http://www.hotrod.com/techarticles/h...g_bang_theory/
hot rod made 451 flywheel hp on an engine dyno. would probably be 370-380 whp on a chassis dyno with a 6 speed/10 bolt F-body.
not many people build 4.8s for NA power.
hot rod made 451 flywheel hp on an engine dyno. would probably be 370-380 whp on a chassis dyno with a 6 speed/10 bolt F-body.
not many people build 4.8s for NA power.
So 451fwp with just ported stock heads, fast, and a cam. Granted the peak was 7000rpm, which I don't want. I'm sure that's from their cam and intake choice. I would suspect an NA combo to make less peak and more average than that, but its a good idea of what's possible.
Do I have to worry about the stock 4l60e or whatever the stock trans is called, at these power levels?
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The bore on the 4.8 is so small it is hard to get power out of them.
I did see that article but forgot about the NA baseline Dyno, thanks.
So 451fwp with just ported stock heads, fast, and a cam. Granted the peak was 7000rpm, which I don't want. I'm sure that's from their cam and intake choice. I would suspect an NA combo to make less peak and more average than that, but its a good idea of what's possible.
Do I have to worry about the stock 4l60e or whatever the stock trans is called, at these power levels?
So 451fwp with just ported stock heads, fast, and a cam. Granted the peak was 7000rpm, which I don't want. I'm sure that's from their cam and intake choice. I would suspect an NA combo to make less peak and more average than that, but its a good idea of what's possible.
Do I have to worry about the stock 4l60e or whatever the stock trans is called, at these power levels?
a GOOD transmission builder will be able to keep a 4L60E alive easily behind a H/C 4.8L.
They are a decent transmission untill you start making over 400hp. If you plan on racing or adding a stall you may want to add a cooler and upgrade a few things first.
TECH Apprentice
Joined: Apr 2011
Posts: 390
Likes: 0
I'm going to be that guy... easiest way is boost. 500whp is cetainly easy with a good set of valve springs, a camshaft that will make power past 5000 rpm, and 12 lbs of boost on a moderate sized turbo (76mm).
4.8s just lack cubic inches, so power can be made, but typically (due to the shorter stroke), it will be a much higer rpm that necessary (also causing parts to wear much faster - power doesn't kill motors, rpm does). A 5000lb truck with a stock 4l60e (and matching 4000 stall to get the turd to move), is going to generate a lot of heat and fatigue parts prematurely.
The easiest way to make N/A power, however cliche', is displacement.
an LQ4 with a box stock Ls3 intake and L92 heads with the shittiest cam you can throw at it will make over 400whp. Put a decent grind and watch the intake valve overlap (monster intake valves do not need to be open nearly as long as say an 862, 706 head tiny intake valve will) and it will make north of 450whp or more.
So spend $$$$$$$$$$$$, wear out parts quickly, and be stuck with no more room to grow.. or find a couple hundred dollar short block, throw some cheap heads on it, and watch it fly.
..or..
Boost.
have fun. If you decide to build the 4.8.. it would be entertain to see how much could be made!
4.8s just lack cubic inches, so power can be made, but typically (due to the shorter stroke), it will be a much higer rpm that necessary (also causing parts to wear much faster - power doesn't kill motors, rpm does). A 5000lb truck with a stock 4l60e (and matching 4000 stall to get the turd to move), is going to generate a lot of heat and fatigue parts prematurely.
The easiest way to make N/A power, however cliche', is displacement.
an LQ4 with a box stock Ls3 intake and L92 heads with the shittiest cam you can throw at it will make over 400whp. Put a decent grind and watch the intake valve overlap (monster intake valves do not need to be open nearly as long as say an 862, 706 head tiny intake valve will) and it will make north of 450whp or more.
So spend $$$$$$$$$$$$, wear out parts quickly, and be stuck with no more room to grow.. or find a couple hundred dollar short block, throw some cheap heads on it, and watch it fly.
..or..
Boost.
have fun. If you decide to build the 4.8.. it would be entertain to see how much could be made!
TECH Enthusiast
Joined: Nov 2004
Posts: 714
Likes: 0
From: Tampa FL
It's not the bore of the 4.8 that gives it a disadvantage. It's the same exact bore as a 5.3 except with a shorter stroke. It will give up on torque and some hp, but it should make similar power to a 5.3. And we all know that well ported 5.3 heads can make some killer power when setup rigth, so there's no reason that this engine can't do the same.
I stand corrected.
I was thinking the stroke was the same but the bore was smaller. I had it backwards.
Yes it will bolt up. 5.3, 5.7, and 6.0 are the same block/crank just with different bore sizes.
EDIT: the 5.7 being the ls1. Yes its aluminum but its the same block casting so everything bolts up.
EDIT: the 5.7 being the ls1. Yes its aluminum but its the same block casting so everything bolts up.
Oh. So if I plan to stroke the 6.0' I might as well use my 4.8 block, bore it, and get a stroker kit. I would probably change the heads anyway.
Are there any oem cranks and rods that can be mixed and matched to create a budget stroker kit? Or just aftermarket?
Are there any oem cranks and rods that can be mixed and matched to create a budget stroker kit? Or just aftermarket?
As for the blocks, I know exterior wise they are all basically the same but inside they might be different. Im not sure if you can bore a 4.8 block as far as you can a 6.0. Maybe someone else will chime in.....
Not to get out of the N/A topic but a friend of mine has/or had (before switching to a 5.3) a bonestock 4.8 procharged (P1SC) on a single cab Sierra with stock exhaust piping from manifolds all the way out to the tail pipe with cats removed, stock 10bolt 3.23s on 22" wheels at 6psi, he made 463rwhp and 413torque on the Dyno and on his first time out with the setup he ran 12.66 in the 1/4.
I believe he still messed around more with the setup and the 4.8, but as far as bonestock 4.8 on a (P1SC) centrifugal supercharger he did a 12.66 at the 1/4 mile at 6pounds of boost.
Here a vid:
I believe he still messed around more with the setup and the 4.8, but as far as bonestock 4.8 on a (P1SC) centrifugal supercharger he did a 12.66 at the 1/4 mile at 6pounds of boost.
Here a vid:
