There is so very much poor information out there about taking a regular 5.3 truck engine and boring it .100 over to make it into a 5.7.
I was hoping there was someone out there that had done it before and could answer a few questions about what parts would be required. I know the cranks are interchangeable with the same stroke. I know that some rods are floating and others are press fit.
Boring 100 over:
We've done it but it's always been with takeout LS1 pistons and rods.
Even the aluminum 5.3L blocks will go out to LS1 bore size. Remember to have it all balanced afterwards. Also, keep in mind, the 5.3L heads have a smaller chamber than LS1 heads, so even if you use stock LS1 pistons, you will see more compression (Not sure of the exact numbers there but nothing too crazy).
But unless there is something wrong with the bores, why bore it out? Displacement isn't the biggest choke point on a 5.3L, it's the smaller valves, convoluted torque-generating intake and world's tiniest camshaft. You'll get a lot more bang for the buck out of swapping the cam (Either any of the other LS family or aftermarket) and intake manifold (Once again, any of the cathedral-port intakes, but avoid the LS2 because it is a compromised design, or an aftermarket equivalent)
In reply to NickD:
If you're boring it out anyway, buying new pistons anyway, might as well pick up the cubic inches!
@Knurled: I've seen conflicting info about the need to balance once complete. Did you have your LS1 combo balanced?
In reply to f6sk:
I just wasn't sure if there was a need to overbore, or if you just wanted to have it done. And if the rod/piston/crank assembly didn't all start life together then it should be balanced. Some guys online say they just put together the rods and pistons and ran with it and as long as you aren't turning crazy RPMs it should be fine, but YMMV
You can get one already done for $600 from summit, that's generally cheaper than paying for the machine work.
Unless you inherited a machine shop!
patgizz wrote: You can get one already done for $600 from summit, that's generally cheaper than paying for the machine work.
Yes!
Found this on the web : ENGINE: Liters: Cubic I: Bore: Stroke: Rod Length: Comp:
LR4 4.8 293 3.780 3.268 6.276 9.5
LM7 5.3 325 3.780 3.622 6.098 9.5
LS1 5.7 346 3.898 3.622 6.098 10.1
LS6 5.7 346 3.898 3.622 6.098 10.5
LQ4 6.0 364 4.00 3.622 6.098 9.4
All information is taken from Chevy High Performance Magazine May 2002 edition.
f6sk wrote: @Knurled: I've seen conflicting info about the need to balance once complete. Did you have your LS1 combo balanced?
Everything gets balanced no matter what. I'm not the guy who balances so I don't know how far off it is, if any.
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