echoman

Ok, so first off I might be able to get a 6.0 liter from my brother for a steal. My first question is whether its a lq4 or lq9? It came out of an '06 Hummer with like 56k miles on it. I have searched around and can't find any definite answers on what exactly it is. I haven't had a chance to look at the head castings either.

Now, as with everyone, I want to have the best bang for my buck. I want to make around the 450rwhp range. My question is which heads should I use? Should I use my 241's on the 6.0 liter? Or should I use the heads that are on the 6.0 liter and maybe port and polish with bigger valves and such? Or leave them alone? I am planning on contacting EPS to handle my camshaft needs when the time comes.

Or should I just keep my ls1 and build it and forget the 6.0 liter?

Let me know what you guys think, any suggestions and opinions are welcome. My car is my sig.

Paul57

My choice would be to go with the 6.0 and a set of 243 heads for great flow and compression. That will be the easiest way to make the type of power you want along with the EPS cam. You can always sell the 241's and/or LS1. In an apples to apples setup the extra cubes of the 6.0 should give you an additional 25-ish ponies. There is no replacement for displacement...when everything else is equal.

stunna p

iTrader: (4)

Id save and go big. As soon as mine lets go... Its 7.0 time son!

Drokkers

iTrader: (2)

what this guy^ said. Go with 6.0 and the 243's and cam. You wont regret it. Plenty of guys on here that have gone that route and came out of it with a "permasmile". Thats the route i plan on going in the future.

NemeSS

iTrader: (127)

No need for 243s, unless you get a ported set. The 317s on the lq9. Flow just as good as 243s. CR is 10:1 for a lq9,bout same CR as stock ls1. If you want increase thr compression, can mill the stock 317s up to .030 and use a ls2 head gasket.
If using an aggressive lobe cam with hi lift, may need to vr in pistons.
All this will require to verify final correct pushrod length size.

echoman

Thanks for the info guys! So, the LQ9 came in an '06 Hummer? Do the 317's have smaller valves than the 243's? If they are the same I might just keep the 317's and have them P&P'd. I will be using my ls6 intake off my motor, do you guys think 450 rwhp or close to it is possible with this setup?

intenseblue

iTrader: (1)

That engine will be an LQ4

Paul57

The valves are the same size. DO NOT have your heads hand ported unless you know of a shop that has done extensive work with LS heads...not just "any" heads. The 243's and 317's flow very similar but I would still go with the 243's to get better compression to achieve the rwhp you want. The turbo guys like the 317's so they are not that hard to sell. Just my $.02.

Bo185

The Hummers had LQ4's and both the LQ4 and 9 have 317 heads!
Either way you can see buy looking for the dish pistons for the LQ4.

http://archives.media.gm.com/us/humm...2/06index.html
IT never says LQ4 in the link but does state HP rating 325hp and compression ratio as 9.4:1 which =LQ4

echoman

Haven't checked the thread in a couple weeks. Thanks for all the help guys! This has been very useful. I will start a build thread when everything gets underway at some point in time.

BODUKE

I'm in the same boat whether too 6.0 or do an 383 ls stroker.

My6speedZ

iTrader: (18)

For you goals you go either way. Truck block is heavier.
383's can run strong. 4' bore opens up more options for heads.

I think alot of people sell the 241's short and with your goals.
You could easily build a very torquey streetable set-up any way you go.

Buying the truck block would allow you to drive your car and build the motor until your
ready to just drop it in.

Also agree on not just letting "anyone" port the heads. Let someone LS savvy do them.

derrickman05

iTrader: (4)

I'm in the same boat as well! I sit at home and jump on some parts like front covers and such so I can build either motor on a stand but don't have a block yet due to this dilemma.

sabersaw30

iTrader: (10)

I like the lightweight ls1. Looking at your sig you would be surprised what a 4000 stall and a nice head and cam package would do to that ls1 you got.
You can build a nasty 6 liter though. Either way you need to build you a strong transmission.Weigh the cost and decide from there.

badazz81z28

iTrader: (6)

I was thinking about this too...

If all things equal, the 6.0 will make 25ish more HP, but weighs more than the LS1. So power to weight ratio would about equal out.

LS1 Racing

iTrader: (15)

Quoted for truth. I have exactly that combo with a small cam, and with the heads milled .030 along with a nice valve job with some light bowl work, I made the numbers in my sig.

243s>317s because you don't need to mill them to get compression.

1nasty86

iTrader: (63)

Another 6.0, 243/799 fan here... I have a friend with a LQ9 with a set of stock 243's and a vindicator.... Car rolls pretty good

echoman

Well dang it. The 6.0 that I initially was going use is now going to be for sell. So, my build is going to have to be my motor I have now, or buy something else already done. With that said it's going to take a lot longer to get this done than expected due to budget. Oh well, that's life. In the meantime anyone want to buy a 6.0 liter?