LQ9 engine

**thopsramair** · 02-26-2008, 07:54 PM

Would somebody please tell me what the LQ9 engine is. I have a friend that wants to put this in a car of his but I am not real sure what it is. I thought it was a truck engine. Anyway if someone could clear this up for me, that would be great. Thanks

**Demon_Z28** · 02-26-2008, 08:17 PM

its a 6.0L LS based engine with out a LSX intake manifold and its an iron block, iron heads, its the engine we have in the escalade here.the L92 is a 6.0L too I think.

**Squirly013** · 02-27-2008, 09:23 AM

Are all LQ9 heads Iron? I heard they're not a bad mod for LS1's with forced induction.

**Firebirdjones** · 02-27-2008, 10:58 AM

They are all aluminum heads.

**C&Cbird** · 02-27-2008, 01:54 PM

The LQ4 heads are iron I believe, the LQ9s are aluminum.

**Firebirdjones** · 02-27-2008, 02:46 PM

Oh okay, I was referring to the LQ9's....although my fathers 2001 3/4 ton chevy has the 6.0 litre LQ4 and it has aluminum heads as well

**C&Cbird** · 02-27-2008, 08:24 PM

I think it was only earlier year LQ4s, but I'm not 100%. I don't really keep up with any of the truck engines other than the LQ9 and the L92.

**m8w6r77** · 02-27-2008, 09:06 PM

lq9 has flat top pistons and better rods. the lq4 comp. ratio is 9.4 to 1 and the lq9 has comp. ratio 10 to 1

**thopsramair** · 02-28-2008, 08:20 AM

So does that mean he can put this engine into his camaro? I am just not real familiar with this engine, and I don't think my buddy is either.

**C&Cbird** · 02-28-2008, 03:40 PM

An LQ9? People are putting those blocks with stroker kits in their camaros and firebirds all the time, it makes a 408. If he doesn't modify it any, it'll be slower b/c it has lower compression than an LS1 and he won't be able to use the LQ9 intake, he'll have to use a ls1 or ls6 intake.

**m8w6r77** · 02-28-2008, 06:54 PM

the lq9 has the same demension as the ls1,ls6, lq4.

**Demon_Z28** · 02-28-2008, 07:21 PM

the Lq9 is an iron block with aluminum heads, thats correct, ive heard of swaps and getting a camaro to run mid 12's. My bad I was thinking of the LQ4 with iron heads.

**Firebirdjones** · 02-29-2008, 04:46 AM

Originally Posted by Demon_Z28

the Lq9 is an iron block with aluminum heads, thats correct, ive heard of swaps and getting a camaro to run mid 12's. My bad I was thinking of the LQ4 with iron heads.

My dads 2001 3/4 ton truck with the LQ4 has aluminum heads,,,,so not all the LQ4's were iron either.
I have the break down in a book here that explains all this, I'll have to dig it up.

**Firebirdjones** · 02-29-2008, 07:41 AM

Maybe this will help.

The LQ4 6.0 truck motor from 1999 and 2000 had iron heads.

The LQ4 6.0 truck motor from 2001 to 2002/03 had aluminum heads.

The LQ9 6.0 truck motor from 2002/03 had aluminum heads.

At some point during the 02/03 model year they made the transition to the LQ9 motor,,,but the aluminum head from the previous year LQ4 stayed the same. Biggest change between the 2 are compression ratio with LQ4 having 9.41:1 and the LQ9 having 10.08:1.

01/03 LQ4 aluminum head casting number 12562317
02/03 LQ9 aluminum head casting number 12572035 (some books also list 12572317)

They both have the same combustion chamber size of 71.06 cc's
Both have the same intake port volume of 210 cc's
Both have the same exhaust port volume of 75 cc's

The iron head of the very early LQ4 production has casting number 12561873 and is identical in everyway to the aluminum head,,,,same intake and exhaust runners, same combustion chambers,,,with the exception of being cast iron of course,,,,,,

**oobadoobin** · 03-04-2008, 08:18 PM

from what i've read the 6.0 iron blocks are almost identicle castings as the aluminum blocks but have a 4" bore and can be bored out slightly since they don't have sleeves so you have a slight displacement advantage and are stronger ( probably not enough of advantage to matter till well over 600 hp) but iron blocks have an 88 pound disadvantage. the Lq9 heads (I believe ) are very close to Ls6 heads except they have a larger cumbustion chamber. the LQ9 is 345 hp stock so its no slouch but has a large oil pan that hangs down too low in cars ( so you have to swap to a car pan). the LQ9 IMO would be a wise choice if running a supercharger or turbo with higher boost but needs pistons swapped out to lower compression, although forged pistons are always a good idea with power adders so this is not a huge dissadvantage to the LQ9.if running natural asp.i would stick with aluminum block if I had a choice, for weight and run higher compression. but usually i don't think the price of a whole new gen III engine is worth any of the advantages any of them have on each other as all the diffrences are subtle between them all ... once again thats my opinion

**m8w6r77** · 03-04-2008, 09:09 PM

the lq4 would be the better ideal for boosted application. b/c it already has the lower the c/r. the lq9 has flat top piston.

**jgh64pkup** · 01-16-2009, 07:24 PM

my buddy has an 01 camaro with an lq9 with an ls6 top end and headers he's in the low 11s

**Sarge** · 01-18-2009, 04:00 AM

And when you bore it out another .030 you get a 408....drop some goodies such as Lunati/Diamond/FAST/Clevite etc. in em and make 600+ all day on motor alone....
Drop it in a 04 GTO and it looks like this....

**Dr.Crash** · 01-18-2009, 09:22 PM

Horse Power TV just did a build up of a LQ9. They made 380HP at the crank for 2k. That includes the cost of the engine. they put it into a SS, it was pretty cool.