Trucker82

Does anyone know if a 4.8 can be stroked and what crankshaft would you use? The reason I ask is because I have a LR4 in my 2000 chevy silverado 4x4, and it was only offered that year in a MANUAL TRANS W/4.8 liter. When I ordered it I went to several dealers because I wanted a 6.0 with a manual trans but they both told 4.8 was it. So....I am worried that something is different with the 4.8, clearance, design, Or something that wouldnt allow a LQ4 or LS1 to be shoe-horned into my 4x4 1500. So I am checking options for my next rebuild.

Thank you Sincerely,

JoeNova

4.8 and 5.3 share a block. Crank and rods are the difference in displacement.

LStang01

Yes i will look up the the thread i had just read it the other day. the 4.8 has slightly shorter rods then a 5.3 so theres the first, then the block can be bored to 5.7. I believe you would then just use the LS1 stroker kits as you are already going to be using the ls1 piston after the bore (summit has them for 600 still i believe if thats more feasible) You would then install the 4" crank and would have a 383 which is basically an iron ls3..

LStang01

crank is the same.. the only difference in displacement comes from a shorter rod length a simply longer rod would bump up the cubes to 5.3 from 4.8 but like i said in my other post it would be best to bore it to the ls1 spec and then go from there as the market for that is way more established and plenty of parts around but i believe its a 4" crank that goes in

MaroonMonsterLS1

Ignore LS STANG, he's So wrong it's not even funny. 4.8 and 5.3 have different crank. They share the same bore, but the 4.8 got a shorter stroke crank and longer rod.

5.3 is 3.780 bore, 3.622 stroke, 6.098 rod.
4.8 is 3.780 bore, 3.267 stroke, 6.275 rod.

A 5.3 crank and rods will swap with the 4.8 pistons to make a high compression 5.3

Block, intake, oil pan, etc etc etc are all the same. The only difference between the 5.3 lm7 and 4.8 are the crank, rods, and pistons which I've outlined above. This makes for a simple swap of the entire engine, or just crank and rods if you so choose.

Little fyi, the 4.8 loves to rev, and handles boost very well. They're good little engines, I love the 4.8 in my 99 rclb

8.Lug

Oh my. The displacement difference comes from a shorter stroke, and stroke length is determined by the crank, not the rods. The length of the rods has nothing to do with displacement on ANY motor. And FYI, the 4.8 has LONGER rods than the 5.3.

JoeNova

For your first two posts here, you're off to a bad start.
Rod length has never determined stroke in any engine.

The amount of travel on the crankshaft determines stroke. The rod is just there to make sure the piston is where it needs to be.

If you take a 4.8 with the piston sitting at the top of the bore and put a longer rod in it, its just going to shove the piston into the head and break. But you're more than welcome to try it.

Floader

iTrader: (32)

The only thing that will get you on a swap for any other LS motor is that your 4.8 is a long crank flange version. Like the early Iron headed 6.0's. Its not a big deal, there are flywheels that make up the difference, but its something to keep in mind.

gagliano7

A 6.0 or LS1 will fit in your truck. The only 6.0's that won't work are the 1999-2000 with the iron heads because they have a longer crank.

KCS

iTrader: (20)

You should really read more and post less. You got pretty much everything wrong.

Floader

iTrader: (32)

I may be mistaken, but I believe that the very early stick 4.8's had long cranks

Trucker82

A longer crank or crank flange. That is the kind of detail that I was after thank you very much! Any Idea of the actual numbers in lenght? Anyone know the length of a LS crank?

So let me see if I got this right.....I could take a 4" 6.0l crank, 5.3 short rods and most likely a short piston. Or can I keep the 4.8 rod length and have enough room on a short piston that the wrist pin doesnt go past the oil ring? Either way I come out with a 383 depending on bore size correct?

I would like to reuse the original block, its already seasoned and thats the kind of guy I am. I know there is no substitute for cubic inches, so I like the thought of a stroker with my original parts.


Any other info is totally appreciated!

KCS

iTrader: (20)

Keep it simple. If you do some research and actually look at the stroker kits available out there, you'll see they come with a 6.125" rod with a .927" pin. The pistons will all be in the 1.1" range for compression height and also use a .927" pin. They all intersect the oil ring so that's not really a big deal. You're going to end up paying more money if you try to deviate from the simple off the shelf combos and you'll see no real appreciable benefit.

Trucker82

Okay well then can you help me with this KCS.....would a LS2 - 7 block be interchangeable with my LR4 given the possible longer crankshaft of the LR4?

This is the start of my research, why not find out from fellas like me first before I start asking machine shops questions? I haven't found much doing google on 4.8 strokers that really has specifics. So I thought this would be the place to start, and I have gotten some good info. So thanks guys.

JoeNova

You haven't actually said what you want other than a stroker. How much of a stoker? 5.3/5.7/6.0/6.2 crank andjd id's will go in your block and give you a 5.3.

if you are after after 5.3, just buy one and replace your engine.

OLDLADYZ71

I'm working on stroking my 5.3 but everything I'm finding is for going max bore on my cylinders with a 4 inch crank, would I be able to do minimal bore and still go with a 4 inch crank? I want to get as much stroke as I can but I don'twant to go max bore just in case I run into an issue down the road.

JoeNova

there is no requirement that you have to bore it at all.

OLDLADYZ71

ok but how well will that work with a 4 inch crank? I was reading about someone doing max bore and then a 4.2 crank and people were saying that would be bad for the longevity of the engine because of rod length and bore of the cylinder. I'm just trying to clarify. Also what would the displacement be on little to no bore with a 4 inch crank?

JoeNova

Bore and stroke are in independent of eachother. you can do one without the other.

If you're after more power, a stroker crank on a 5.3 is definitely not the most cost effective option. A cam and tune will make a huge difference.

OLDLADYZ71

thank you that's very clarifying. I hear what your saying about cam and tune, I'm doing full rebuild on the motor.