IRONFIST

Just got to thinking if I wanted to replace rods and pistons with forged ones or if I wanted to go 383 can I do it without yanking the heads? I ask because my friend has a very low mileage c5 that's pro charged and he wants a bit more assurance he won't wreck that mint block. We can do it without taking apart the top right?

Whiteaw57

iTrader: (2)

I dont think you will be able to get the pistons past the main bosses. Take the oil pan off if its out of the car and be sure you can see the whole circumference of the cylinder bore and clearance to get the piston out. Not sure how you will get the rings compressed either. I think for simplicity I would bite the bullet and get head gaskets and bolts

buddhaz06

iTrader: (8)

Were you planning on dropping the cradle and holding the engine up somehow? It's a lot easier to just drop the whole drivetrain out and then just put it back in together. You couldn't get the crank out either without pulling flywheel or flex plate.

canada4g63

pull the heads.

1bigoldman

x2^^^^
Even if it can be done it would not be worth the hassle.

gregrob

iTrader: (8)

You're not ******* serious? How the hell are you going to hone the block?

3pedals

iTrader: (3)

It cant be done out the bottom on an LS engine

remauto1187

iTrader: (1)

You cant even do this on a GEN1...why on earth would you want to?

You know a guy doesnt know what he is doing when he doesnt know that the main journals are in the way of pulling a piston out from the bottom of the bore on a chevy! WOW!

sfc rick

What a complete cluster***k ! Just pull the heads!

91sonomast

lol exactly what I thought. Now even if you could get the pistons out, there is no way to hone the cylinders without scarring up the heads.
You need to do one of two things before you touch a wrench or possibly both:
a) do some research and reading on LSx engines to expand you're knowledge and make sure you know exactly what you're doing before you mess something up.
b) drop the car off at a shop and pay them to do it.
I mean this post as nicely as possible. Just trying to make sure you don't mess anything up, there is nothing wrong with asking questions, it's a very good way to learn. You're gonna be time, money, and less stress ahead if you drop the engine out of the car, I wouldn't say it will be impossible to do what you want to without pulling the engine, but your hands and forearms are going to be very bloody if you don't. Plus after you hone the block you need to clean it out good and you can't do that with the oilpan on the engine.

rickyzZ28

iTrader: (28)

Besides all the other factors listed above, you will still need to grind the rings to fit the bore of the motor. Like said above if you lack the basic knowledge of engines and how they work, you may be better handing this job over to a professional.

IRONFIST

I'll let him know it's not possible, lol. I've never built an LSX.. Most of my knowledge is airplane related. Most I've done is heads and cam on my own car. Although I'll be putting an LSX in my trans am this month I'll be buying the built short block so won't touch the rotating assembly at all. Thanks for all the info.