Anyone using the LQ9 6.0 liter engine?
Thread Starter
Melting Slicks
Joined: Mar 2005
Posts: 2,252
Likes: 181
From: NE OH
Anyone using the LQ9 6.0 liter engine?
I'm wondering if there's any advantage to using the LQ9 6.0 liter motor over the LS1 or LS2 motors....From what I can tell most things will bolt up, to include intake, heads, accessories. The stock low compression LQ9 heads are good for us FI guys..so is there anyone out there using these?
Instructor
Joined: Feb 2005
Posts: 177
Likes: 0
From: Tampa FL
Had my '03 LQ4 (same as LQ9 except for heads and cam I believe) in my '98 z28 with no problems. Just had to use my stock '98 temp sensor in the driver side head as the LQ4 one was a different style plug but the sensors were a direct swap. Also had to improvise with the coil packs as the '98 coil packs and valve covers were different. I am about to put the LQ4 in my '01 C5 now that I have forged internals in it. The LQ4 and LQ9 dont disapate heat as well as the aluminum motors so I will have to upgrade my radiator as I had some cooling problems in my '98 z28 with the factory radiator. You will have to use your C5 intake, water pump, alternator and brackets, accessories, etc. The LQ4 block will drop right into the C5 mounts and has all of the necessary bolt holes and plugs already drilled or placed. This is all I can think of at the moment. Feel free to ask any questions and I will answer if possible, anyone else have different experiences?
4th Gear
Joined: Jan 2005
Posts: 4
Likes: 0
The LQ9 has the same heads as the LQ4 unless you get a LQ4 with iron heads(only produced for first two years). The aluminum LQ4/LQ9 heads are the same design as the LS6 only with larger combustion chambers. The LQ9 also does have much beefier rods as well as different(flat-top vs dish) pistons from the LQ4. The LQ9 is good for high hp applications because the iron block is strong, as well as having stout internals, but it does weigh an extra 65 lbs. Just have to decide if you would rather weigh 65 lbs less, or have 18 extra cubic inches.
If you are going to use the whole motor, take into effect that the LQ9 has about a 10.2:1 compression ratio(10.0:1 as advertised, but 10.2:1 if you do the math) as opposed to the LQ4 which is around 9.4:1. Parish was putting down a little over 650 at the wheels with his basically stock LQ4 (arp fasteners and bolts) before it popped, and that one has the weaker rods of the two.
If you are just going to use the heads, then either way it is hard to go wrong with them. They flow like LS6 heads and will lower your compression significantly
If you are going to use the whole motor, take into effect that the LQ9 has about a 10.2:1 compression ratio(10.0:1 as advertised, but 10.2:1 if you do the math) as opposed to the LQ4 which is around 9.4:1. Parish was putting down a little over 650 at the wheels with his basically stock LQ4 (arp fasteners and bolts) before it popped, and that one has the weaker rods of the two.
If you are just going to use the heads, then either way it is hard to go wrong with them. They flow like LS6 heads and will lower your compression significantly
Le Mans Master
Joined: Apr 2002
Posts: 7,281
Likes: 5
From: Boston
Thats what I have in mine and it works like a charm, as a matter of fact the iron block runs cooler than the aluminum one. I never ever get past 194F on hot days in traffic with AC. It always runs at 193-194.
The only downfall is that it weighs about 80lbs more than the LS1.
The only downfall is that it weighs about 80lbs more than the LS1.
Le Mans Master
Joined: Apr 2002
Posts: 7,281
Likes: 5
From: Boston
Originally Posted by muncie21
Wow, lots of experience here on this motor; wasn't expecting it.
I'm thinking of going with a LQ9 block when it's time for a new motor rather than trying to convert to a LS2.
I'm thinking of going with a LQ9 block when it's time for a new motor rather than trying to convert to a LS2.
You can get a nice forged LS2 402 for 3999 from some of the forum vendors, I would look into it if I were you.
