LQ4 or LQ9

Printable View

08-21-2009, 01:30 PM
EastCoast1st

LQ4 or LQ9

Let's say I wanted to swap a 6.0 into a NBS 1500, with plans to build the motor to 500-800HP. Which would be better, the LQ4 or LQ9 and why?

(this is assuming the LQ9 is going to cost more)
08-21-2009, 01:37 PM
PurpleMinivan

Nitrous? S/C? Turbo?
08-21-2009, 02:09 PM
RedHeartbeat

A salvage yard LQ9 is going to cost more due to the fact that there aren't as many available as LQ4's. LQ9 has more HP, better rods and higher compression.
08-21-2009, 06:58 PM
EastCoast1st

Quote:

Originally Posted by DBTBSS

Nitrous? S/C? Turbo?

I have no idea yet, but probably a super charger or turbo. Definitely not Nitrous.
08-21-2009, 08:11 PM
keniff

LQ4 would be best for a FI lower compression is best for that. LQ9 is best for staying NA if im correct.
08-22-2009, 10:32 AM
EastCoast1st

Quote:

Originally Posted by keniff

LQ4 would be best for a FI lower compression is best for that. LQ9 is best for staying NA if im correct.

What is FI and NA?

Any other input???
08-22-2009, 10:36 AM
Vicinity

Quote:

Originally Posted by EastCoast1st

What is FI and NA?

Any other input???

FI = Forced Induction (SC or Turbo)
NA = Naturally Aspirated (Cubic Inches, Raw Motor)

I'd go with the LQ9, if you ever add a turbo, swap the heads to raise lower compression to whatever you need. LQ9's run about $1k used on ebay, $2.5k rebuild.
08-22-2009, 12:56 PM
Sleaper

Quote:

Originally Posted by Vicinity

FI = Forced Induction (SC or Turbo)
NA = Naturally Aspirated (Cubic Inches, Raw Motor)

I'd go with the LQ9, if you ever add a turbo, swap the heads to raise lower compression to whatever you need. LQ9's run about $1k used on ebay, $2.5k rebuild.

The only difference between the LQ9 and LQ4 is the pistons. LQ4 has dished and LQ9 has flat tops, heads are the same. Compression on a LQ4 is around 9.4 and LQ9 is 9.9. You could still run a turbo on a LQ9 but you wouldn't be able to run as much boost as the LQ4 due to the overall compression ratio or dynamic CR. It's the age old question: Higher CR and less boost, or lower CR and more boost.

I would go with the LQ4 since they are cheaper to begin with. To reach those HP goals, you're going to probably want to go forged internals anyway. Get a couple T-76's (turbos) on there and make your 800rwhp.

The other option would be to get the LQ9, forged internals, nasty cam, worked heads and spray the piss out of it. Just depends on what you prefer.
08-22-2009, 01:57 PM
Gladiator 6.0

i have the gen-III lq9 on my 2000 xcab and the gen IV-ly6-iron block 6.0 on my 2007, if you want to be over the 500hp zone you should go forged or stroker. the lq4s and lq9 that my team owns are in the mid to low 12s motor and one whole sec less on nos.
08-25-2009, 12:16 AM
ShredSled

I was wondering a bit myself.

I just recently found a pretty cheap LQ9 longblock out of an '06 Escalade that I should be going to pick up tomorrow.

At this point I'm not sure if I want to go with forged internals or not (my wallets not that deep at the moment). But, if this was a route one was to take, it seems that you'd end up with the same results whether it is an LQ4 or an LQ9 that you began with, correct? I've been assuming same iron block?
(this would also bring up a related question, which is the best route to go for forged internals?)

Also, I thought I remember reading somewhere that after '05 something was changed in them, possibly the rods? Anything else? Can anyone confirm with details?

And, what head castings were paired up with these engines throughout the years? As far as I know, 862's and 317's. Any others? Differences? Which is the preferrable casting?

Thanks in advance for the input.
08-25-2009, 12:20 AM
ma.racing

i would go lq4 sens your building it and just bore .030 and 4in stroke that bad boy na but for real lq4 if your building its cheaper and you plan on goin with new internals anyway
08-25-2009, 07:33 AM
Sleaper

Quote:

Originally Posted by ShredSled

I was wondering a bit myself.

I just recently found a pretty cheap LQ9 longblock out of an '06 Escalade that I should be going to pick up tomorrow.

At this point I'm not sure if I want to go with forged internals or not (my wallets not that deep at the moment). But, if this was a route one was to take, it seems that you'd end up with the same results whether it is an LQ4 or an LQ9 that you began with, correct? I've been assuming same iron block?
(this would also bring up a related question, which is the best route to go for forged internals?)

Also, I thought I remember reading somewhere that after '05 something was changed in them, possibly the rods? Anything else? Can anyone confirm with details?

And, what head castings were paired up with these engines throughout the years? As far as I know, 862's and 317's. Any others? Differences? Which is the preferrable casting?

Thanks in advance for the input.

It depends on what direction you want your build to go. If you go NA, then you would want a higher CR. If you FI, then you would TYPICALLY want a lower CR. If you are going to buy forged internals, then it won't matter if you get a LQ4 or LQ9. If you go FI, then you might want to bore it .030 over and stroke it to get a low compression 408. This is becoming fairly common and making some BIG numbers. Anything 01+ should come with 317's. 317's have the largest stock combustion chambers (72cc) out of all the stock heads. 243's are nice since they have good flow but give you a bump in CR if you are looking to go NA.

What are your HP goals? What power adders are looking to do (Nitrous, Turbo, Scharger)? Daily driver or mostly track use? The answer to these questions is a must to figure out the right direction to go.
08-25-2009, 09:10 AM
SCIV

If you want 800hp, then you will need to go forged, so pick up a LQ4. Cheaper than a LQ9 and more abundant so less cash outlay to start with. Stock crank is plenty strong, so just get new rods & pistons.

:twocents: