Badmire68

iTrader: (55)

What are the differences internally about the 2 motors? besides the cast iron and aluminum blocks of course. I know they use a different bore, so I take it they each use a unique piston. But what about the rest of the engine? Just wondering what will swap from one to another if using a 6.0L block?

marc_w

I'm no good at this stuff... but as I understand it, the 6.0 bore is what's used for a 408 or 427 stroker kits.

There are two 6.0 blocks... the LQ4 and LQ9. LQ4 has dished pistons, and (approximate) 9.4:1 compression. The LQ9 has flat-top pistons, and 10:1 compression.

Of course neither will matter with a stroker kit, but if you're looking for a junkyard take-out..........

Heads, cam, lifters, intakes, etc, will all swap. Truck-to-ls1/ls6/FAST Intakes require a few easy-ish mods on the trucks.

Badmire68

iTrader: (55)

so is the actual rod length the same in the 2? I was wondering how they get the cubic inch difference with just a little bigger bore in a 6.0 over the 5.7? I figured the 5.7 and 6.0 rod length was different. Ialso heard they use the same crankshaft.

robertbartsch

In a year-or-two a new Gen 3 motor will be out that has 3-valve heads - it will be rated at 500HP?

jrp

iTrader: (16)

all internals swap over besides the pistons, obviously

Badmire68

iTrader: (55)

thanks for your help, that answered my question

PREDATOR-Z

JRP,
Does an iron block 370cu LQ9 need stage 3 heads or 5.3 2E be OK?

WS6snake-eater

I know that the 6.0 iron block weights about 60 lbs more, but will it make any more HP in a direct swap, due to the extra cubic inches? If so how much more HP is to be had? I'm talking about apples to apples, no extra modifications just a strait swap. Also, since it is an iron block, will it be safer to use with N2O?

jyeager

The extra cubes add only that marginal bit of additional power. But the main value of this block is that you can bore it, then stroke it and have a very respectable displacement. If you just swap the stock one over, I don't consider it to be worth the 60lb penalty.
As for N2O, when was the last time a nitrous failure was the result only of the block breaking? It might be safer for nitrous if you're throwing a 500+ hp shot at it and you've got internals designed for this.

WS6snake-eater

Here was my reasoning... Currently my car is putting down 450 rwhp with the stock 346. That equates to 1.3 rwhp per c/i. If you could keep the efficiency at a constant 1.3rwhp per ci, then one could assume that by adding and extra 18.3 cubic inches you should be able to gain 23.8 rwhp from just the block swap alone. Also I would think that with the extra cubes, one might be able to further utilize the new FAST intakes that are out. It has been my experience in searching that these intakes are making pretty decent gains with the bigger cubed motors. You do have a good point about the nitrous failure. It is rarely caused by the block. I wonder what the area under the curve would look like also with switching blocks. I would imagine that theTQ would go up considerably especially in the lower RPMs, which is something that us big stick guys really need. Does anyone here have experience with swapping just the block? I kind of figured that most would not go this route because it is a lot of work, to do for such a little gain. If most people are going to change out the bottom end, they go all the way, with the forged, bored, and stroked blocks. Maybe I should pioneer and see what happens. Any more thoughts on this??? BTW 60 lbs can be made up real easy

MyLS1Hauls

iTrader: (2)

The cranks are slightly different also. The 99-2000 6.0L cranks can't be used in LS1/LS6 blocks or in 2001+ 6.0L blocks. Also, 6.0L cranks arent lightened like the LSx ones are. I've seen guys just upgrade from a 5.7 to a 6.0 no other changes and they picked up about 20 hp.

Predator, the 6.0 block needs heads with chambers that will accept a 4.0" bore, so they will need to be modified...also with LQ9 pistons, the compression ratio would be pretty high with stock 5.3L heads.

jyeager

I will say that if you are doing a whole engine rebuild you can do an iron-block 400+ ci motor for cheap (at least compared to a 383 ls1).
If you are doing a complete rebuild there is compelling advantage to the iron block.

If you are just wanting 30 extra cubes...I don't know.

WS6snake-eater

Do you recall how much TQ they picked up? I would think that there would be some TQ gains down low.