Shtstr

Hi everyone.
trying to work out what my engine actually is from factory.
Block casting number is 12561168 and for all purposes makes it a ls6 bottom end.
Inlet and exhaust manifold are ls6 items.
But the cylinder heads are 241 casting.
engine is out of a 2004 vy lx8 adventra awd sports wagon in Australia if that makes any difference.
From my understanding Holden ordered them this way from GM for what reason I have no idea.
Or is it just a run of the mill ls1 that has used a ls6 block and manifolds??

Pulse Red

My Monaro is a 2004 that I bought brand new. I understood at the time that VY Series 2 and VZ LS1 engines were a hybrid ordered by Holden for our cars, using LS1 parts that were being phased out with the end of the Camaro etc and the move of the Corvette to LS2. However, that may be wrong and also they were actually used elsewhere in the GM world. I don't know the US spec car details.

I read these 2004 VY II and 2005 VZ engines had the following over the 2003 VY engines.

*Still used 241 heads*
LS6 block
LS6 manifold
LS6 valley breather
Stronger floating pins
Bushed conrods
Revised pistons
LS2 head bolt configuration
Better design oil pan.

The US spec 2004 LS1 GTO had a revised cam (plus a couple of other changes) on top of this.

Shtstr

The car it came from is a vy2 2004 model.I have the vin number but the Australian vin is different from the USA vin with regards to G or S for ls1 and ls6 engines. ​​​​​​​The 8th letter in the vin is an F .
So completely different to the USA system.​​​​​​​

Pulse Red

Australia didn't ever get any actual LS6 engines. Only LS1. No Aussie LS1 ever had the 243 heads either, just the changes I listed above for the 2004 onwards LS1s. I believe if your VIN says 04, you have the LS1 spec I listed.
​​​​​
Our US friends will confirm, but I don't think in 2004, GM were selling any alloy LS1 5.7s. Holden were the only customer for this engine.

Shtstr

Vin is
6G1YM84F54L203003
The search i did come back as a completely different car all together.
car is a vy 2 holden adventra awd sports wagon. 2004 model. ​​​​​​​

Pulse Red

Ah, sorry, the engine number had the 04 in the start of it, not the VIN. So, VF04 is what you want at the start of the engine number.

Shtstr

According to 1 check I did it says it's a Holden calibra.
That's totally incorrect plus it said it was a 5.7 ls1 and as far as I know even the calibra didn't come with a ls1 v8 engine either.

Pulse Red

Nah, Calibra certainly didn't come with a 5.7 , hahaha

Pulse Red

I thought it was sorted by 2004 but a lot of earlier LS1s around 2001 to 2003 were swapped for rebuilt LS1s due to oil consumption issues. My 2002 VX II SS was purchased new by me and had this done and I don't understand how Holden were allowed to provide my car an older engine but they did. Perhaps your donor car was given a replacement engine.

Shtstr

​​​​​​​No it's the original engine. Just weird that Holden used ls6 short motors with all ls6 manifolds but opted for the ls1 241 cylinder heads.​​​​​​​I've been told that all ls1 engines from vx onwards used this type of built engine from factory. ​​​​​​​why the hell would a factory opt for only 3/4 of a ls6 engine with cylinder heads that don't match the GM factory engines.

Pulse Red

​​​​​​​Nah, I don't think that's right. People get confused because the VX got the LS6 manifold, they thought it was an LS6 block too. As I say, I also had a VXII SS. I'm confident you will find the only cars that got the LS6 block were 04 onwards, along with the extras I listed. The part LS6 is for the reasons I listed above. They wouldn't use actual LS6 heads, they were expensive with sodium filled valves etc.

​​​​​​​

Shtstr

​​​​​​​​​​​​​​I know a limited number of ls2 engines in the change over received the 243 heads. But they are 6L blocks with the ls6 243 heads fitted.​​​​​​​not sure what they came out in but wasn't a lot of them in Australia. ​​​​​​​I know of 1 engines that came out of a vz ss that's in a hatchback torana that has the 243 heads on it. All factory fitted.

Pulse Red

​​​​​​​Not a limited number, all Aussie LS2 got the 243 heads. These 243 do not have sodium filled valves like the LS6 243s. However, only the HSV here got the LS2, including some HSV Coupe. Pretty rare here as you say. Many people call the L98 etc an LS2, which it's not.
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LS1Formulation

iTrader: (13)

To answer your question, no, GM didn't build any 5.7 liter engines after 2004 in the US.

99 Black Bird T/A

iTrader: (4)

In the US, 12561168 = LS6 block, used 2001+ to build both LS1 & LS6 engines.

A small percentage of fbody's got 12561168 = LS6 block for their LS1 engines in 2001. By 2002, roughly 20 to 25% of fbody LS1 engines used an LS6 block with 241 heads.

In my opinion, an LS6 block can be built to LS6 specs or better and be a defacto LS6 engine. I've had a spare LS6 block for 20+ years, I'd planned to do that with until learning the LS6 block is the weakest aluminum block the LS1/LS6 Gen 3 family. We used a seasoned early LS1 block for my 383 LS stroker instead of that LS6 block for that reason. The LS6 block can excel better at NA high rpm applications.

Pulse Red

In the US, how was it decided which Camaro got the LS6 block? Or was it random?

What I was always told was that here in Australia, due to the distance, Holden would order a certain number of LS engines fron GM well before the cars were produced. So, we would always have the older engines until the 4th Gen F body cars were ceasing production (mid 2002) and the Corvette was the only other car running the 5.7 alloy LS1 before it moved to the LS2. Then we got the latest spec engines.

I'm unsure if the cutover for us was in 2003 or 2004 but was told by those who should know that for us, the upgraded version had 04 in the engine number.So, we had the older spec LS1 block cars into 2003 and then got the LS6 block cars for 2004.

We also got the LS2 for HSV when the Corvette did, which was a big deal because we usually were behind as mentioned. HSV could control their production numbers too, being more limited editions, Holden really couldn't.

Shtstr

That would sound about right because the early ls1 engines had oil pump problems and excessive oil consumption but would mean the early ls1 block would be weaker than the later ls6 block and also the later ls6 had better oil gallery delivery system and oil pump than the first of the ls1 engines.

grinder11

iTrader: (1)

Totally agree. Like you, I'm certain that I remember all 2001-up 5.7 aluminum blocks were LS6. Maybe some VERY early LS1 cars got some leftover LS1 blocks, but I believe youre correct that GM went to all LS6 blocks, with LS6 intakes from '01-up. The LS1 block was kinda phased out after 2000......

grinder11

iTrader: (1)

I think you're correct on the '97-'98 blocks being weaker, due to less aluminum. But when you get to a certain power level, I've also heard from Steve D.@RED that the LS6 blocks main webbing is weakened due to the cast in vents for bay to bay breathing. I believe the oil galley issues were eliminated in early to mid '99 blocks. My 2000 block had the improved oil galleys, but also had a noticeable piston slap when temps went below 55°. Under 55°, the damn thing sounded like a diesel, and I'm not exaggerating. It only lasted for maybe 10-15 seconds, but scared the Hell outta me the first cold Fall day!! It also used some oil. Maybe got 2,000 miles/qt, maybe a bit less. One of my better runs at the strip in my '00 C5 came when I was low on oil (according to the OEM low oil sensor)! At that point I had no idea the car was using oil, or was a bit low, because I'd only had it for maybe 3 months. Didn't think it needed to be checked every month!! About a month before I went to the strip, I checked it and it was down maybe a half quart. No big deal. When I got to the strip for maybe the third or fourth time, I ripped off my first high 12 second run. That surprised me. So did the nearly 110mph trap. Low 13s@107-108 mph the first 2 or 3 weeks. I about **** when I got my slip, got back to the pits, and the low oil light came on!!!! No harm done, except my heart probably beat at least 6 months off my life!!!

Pulse Red

I may have misunderstood the figures put forward by 99 Black Bird T/A. I thought it was being said that a portion of the Camaro were getting LS6 (up to 25%) and the rest of them were LS1 still until the end of production in mid 2002. So, in the USA, was it a running change to move from the LS1 to the LS6 block? In 2001 as mentioned by grinder11?