what's the difference?

[fieroman87]

i'm having trouble identifing the the difference between the 3.5 LX9, 3.6 global and the 3.9 vvt blocks and how they relate to the 2.8 that i know and love. can anyone give a comprehensive list of details for the first three? and most importantly, how GM gets 3.9L out of a 60*?

thanks
Arty

[bszopi]

Comprehensive list of details? Sure... this is for the 3.6 global (and all other new DOHC engines):

http://60degreev6.com/discussion/kb.php?mode=article&k=66

And this is for the 3.9 (this discusses the non-VVT, but the 3500 and 3900 VVTs use the same block as this).

http://60degreev6.com/discussion/kb.php?mode=article&k=10

[fieroman87]

and how do these two relate to the LX5? (short star)

[bszopi]

Not at all...

[fieroman87]

ok, let me ask the question in another way: How do these blocks differ from eachother (LX5 and global 6s), and how do the 3.5/3.9 pushrod blocks differ from the 2.8/3.6 DOHC blocks?

the reason i'm asking is i'm trying to decide which aluminum block will best suit my goals for the upcomming engine swap. i'd prefer to stay w/ a DOHC setup do to the higher RPMs that they are inhierently capable of, but i'm not counting out the new pushrods.

thanks,
Arty

[bszopi]

I don't have too much time to go into detail, but I can tell you that the short star is a 90šV6, not a 60šV6, so that would be your biggest difference, and hence the reason I said not at all.

[fieroman87]

ok, so now it comes down to how much the bottom ends can handle and weather or not twin turbos and 550hp is feasible on low boost.

i have it in my mind that i'm going to use the new G6 6spd trans. i'm wondering if it'd be worth the effort to try to mate the LX5 to the tranny or go w/ something that already fits. i KNOW that the LX5 bottom end is stout and will handle about 650-700 HP stock and can take 10000 rpm without much effort. how does the global 3.6 compare? has anyone pushed the limits of this platform? is there any performance aftermarket for these engines like there is for the N* and S* blocks?

which is the better aluminum DOCH V6?