Would it be possible to bore the engine out and keep the 4.8 crank? I've been toying with this idea myself but can't find the correct rods for it.

 

if i remember right, the piston hieght is the same on the 5.3 as the 4.8 even though the 5.3's are dished and the 4.8's are flat top. meaning you could use 5.7 pistons and stock 4.8 crank and rods. they just used a longer rod to make up for the shorter stroke.

 

does anyone know what the compression would be if I bored my 4.8L to a LS1 bore, keeping the stock crank, rods, heads, ...


I think right now stock it is 9.6:1


oh, and flat-top LS1 pistons!

 

should be around stock ls1. well it depends on what heads you go with too.

 

compression should be higher then the LS1.
the 4.8 heads have a much smaller combustion chamber.

guess im kicking around the same idea as a few of you are too.

right now im looking at droping in a 4.8 crank in to a 5.3.
with the smaller rotation and the shorter 5.3 rod, compression should really drop.
add a set of 317 6.0 heads to drop it more.
valve clearence should be more then enough for any cam.
just wondering what the max boost level will be before any knock shows up.

 

if you use the 5.3 rods the rotating assy will be too short by over .3" that quiet abit i would think.

 

Your limit is going to be valvetrain WAY before bottom end.

If you had a solid roller revvign to the limitations of piston G's- you might have a case.

 

yeah it is, but as you know, the lower the compression, the higher the boost level.

 

Hmmm . . . I was thinking of builing up a high revving 4.8 for my AutoX car . . .

4.8 = $800
LS anything = $1800+ (At least in my neck of the woods)

A crazy wild cam in a 4.8 @ 7200 rpm w/ T56 and 4.44 be a dream 2800 lbs car

 

what if you used the 4.8 pistons, and 5.3 rods and crank????? would this work and what would it be like