Texas_WS6

iTrader: (9)

I was under the impression the LS3 and L76 used the same cylinder heads, at least the head it self is the same. I also thought the only difference between the two was the LS3 had VVT were as the L76 does not.

stevenp

? I honestly have no idea...I just thought that since it makes sub 400hp that the heads were diff.
The g8 makes kiddie power compared to its comparable relatives. so I really don't know...haha.

Edit: the heads are diff.
On the other hand the l92 heads are the same as the ls3 heads...I think

OneBadLS

This is true, I do know that the LS3 is a direct swap it needs is a convertor box to make the reluctor wheel work. Is the wiring harness direct for the LSx as well.

I though about doing this to a CTS-V as well but then again I would have to spend another 2-3 Grand on a damn rear. I just want a 10 sec car. I mean I've seen 9 sec TBSS. so it can be done. they had a built LSx in it as well. I am wondering if an LSx 454 CTS-V can accomplish that and beat the snot out of Terminator Cobras and what not.

stevenp

Depends...sometimes cobras are the best. sometimes 454 lsxs are the best. With a 454 lsx with tfs 235 heads with a big 260/260 cam and a ported fast 92...I would feel pretty good about beating a cobra, but then again I have a 3500lbs. car and your talking about a 3900 lbs. car and with an iron block (add about 90 lbs.) and what if the cobras are heavily modded...they can make good power too and they weight 3600 lbs.

OneBadLS

see heres the thing though, it doesn't always ball down to who has the bigger cam. Bigger doesn't always mean better you want a cam that will give you good enough power band for both low end and top end. Ill have to sit down one day and see what I really want.

Texas_WS6

iTrader: (9)

LSx 427, 240/230 114, LSX Drc heads, 15psi FI, now you have something with plenty of low end, midrange, and top end. They make great all around power because of the FI, but the lsx with fi will make more.

stevenp

Well that wan't really my point...my point was that you have a car that weighs 3900lbs. and you want to beat a car that puts down 400 hp and weighs 3700lbs unmodified.

Cams are a completely diff. story...I just through that one out there. I probably would use something completely different than that, but it all depends on what I want.

OneBadLS

Yea I understand where your coming from. I guess it be best to swap in an LSx or LS3 and stroke it out. either or Ill probably stroke it out to a 427 if not that then a 454.

stevenp

either way it will be fast.

GeorgeInNePa

The heads on a L76 and an LS3 are the same heads (the L92 head). They also use the same LS3 intake and 90mm throttle body.

The main difference between the motors is 12cubes (6.0 vs. 6.2), the AFM system, and cam shaft. The cam in the L76 is .472"/.476", that's the main reason the G8 is so underpowered.


PS

The L76 uses a solid intake valve, the LS3 uses the hollow stem.

stevenp

Ahh thats why...guess I was wrong. So with an ls3 stock cam it will pull to 420? So that means with a decent aftermarket cam it can pull much harder...wow

Bring the Noise

Don't forget if you get a LSA you will need to get a LSA fly wheel (8 bolt pattern).
Gen III and GEN IV's normally use a 6 bolt pattern at the end of the crank.
LSA uses an 8 bolt pattern, and LS9 uses a 9 bolt pattern.
Why? no one at GM has said why, but that is how the motor how they did them.

But if the car your put'n the motor in is a manual then the LSA clutch is a dual clutch similar to the LS9's....

stevenp

That would immediately deter me from putting an lsa in there...thats bs on gms part.

OneBadLS

that just means its more money then its worth.

GeorgeInNePa

There are a lot of G8s that have aftermarket cams now (with and without head work) and they are in the 400 to 450 HP range.

The ci difference in the L76 and LS3 seems to be about a 15-20hp difference, everything else being equal.

I'll be cam swapping this fall.

stevenp

Well I kind of imagine the l76 as an ls2 with an ls3 top end so I kind of put the ls2 and ls3 in the same areas and I put the same power levels on them even though they are different engines. But thats absolute bs on gms part...its like they want for no one to work on the engine without paying through the nose.

OneBadLS

We"ll I've made up my mind If I do indeed decide to do this, I am going with either an LS3 or LSx. It seems like the LSA would be to much of a PITA.

Taken4granted

It will be a pain in the ***, but you will get a lot of attention and others will follow setting a trend, and you will be the first to say I started it.

SS#1230

i didnt read all the other posts on this thread but i was thinking the exact same thing he is.

especially if you are planning on dumping more cash on heads and other mods after spending some serious coin getting the lsa in your car.

you could make a serious monster on your own in a similar configuration.

any LS block with a good head and cam set up (do some research on blower cams) and a supercharger will put down gobs of HP!

ive got a vortech blower on my LT1 and i thought for a long time that centrifugal blowers were the cat's meow, but after reading a lot, id really like to have more boost and torque down low. while the roots blowers aren't as effecient at higher rpms, i really like how much they flow at low rpms.

but of course, if i had no boundaries of smog tests and money.....TURBO is the best way to go IMHO. and you cannot beat the sound of a spooling turbo!!!!

00fastta

If you had the money...don't ever look at a lsa again...instead get an ls3 and put a twin turbo setup on there ftw