midwestjunk

iTrader: (2)

I have a LQ9 block that is not filled. 4.030 bore for 408ci. I'm curious the nitrous limits on this block. On a 400 shot its around 1,050hp on the engine dyno. How far can I push it before the block fails? 1,150hp gonna be ok if I spray more? What are you guys hitting these things with on a stock block?

willyp

Subscribed and hoping someone answers your thread! I'm building a very similar set up. Best of luck!

dekan513

iTrader: (2)

ive been looking into lq4/9 stuff. thinking about putting my ls3 up and going iron for a big hit. but what ive been told is 400 shouldnt be a problem with right tuning.

Zmg00camaross

iTrader: (11)

No experience but i think it would work. I never heard of anyone splitting a block from heavy nitrous, seen a couple of blocks with melted deck surface after they torch a head.

ATwelveSec02Z28

iTrader: (17)

I ran my old 6.0 iron set up with a single 87 jet... Which is quite a bit less than 400....


I got the block from summit back when they were selling them for $700.

Biggest issue I had was keeping the bores squared. I tried jetting to a 93 jet, and no matter where I was on timing the engine just wasn't happy. With 87 jets it would maintain 12-14" of pan vacuum. Up the jet to 93 and pan vacuum was erratic and losing. Pistons came out with a small amount of skirt scuffing. This tells me that the block was moving a bit, and rings were losing seal, or poor machine work...

Also remember that it is not necessirily a horsepower issue but more of a load issue. A light car will behave differently than a heavy car with identical engine and tunes.

Major Shart

Subscribing.

Killer5.3

iTrader: (1)

I know of one that has been run for over two years and 100+ passes on a .040 jet fogger and zero issues. Everything looked great on recent refresh. No block fill. An engine plate will help a lot with block movement.

Me24seven

Subscribed

MUSTANGEATER

iTrader: (10)

I had the same experience on an LQ based motor. I always assumed it was the core shift/cylinders moving around.

I'm curious to see how an LSX block will hold up.




I've only see one LQ9 block crack and that was on a Turbo setup.