LSX350Z

I have changed my original plans to build a Ls1 due to the limits on bore and heads. I have now purchased the LSX iron block. What is the safest bore I can go with. My builder told me around 440cid. My initial impression was you could go all the way up to 480cid with that block. At the minimum I want to use the LS7 heads and possibly the new LSX heads. Is a 454cid safe and possible? If so what should I tell him?

pist0lpete

iTrader: (3)

454 shouldn't be a problem but 440 is a bit safer. If you decide to go 454 make sure and work with a piston manufacturer to get a piston thats designed well for the longer stroke.

KCS

iTrader: (20)

I'm pretty sure a 4.185" bore is perfectly acceptable in most applications. I'm sure you and your builder have talked more about what you plan to do, at least more so than what you've told us, so he may suggest the 440ci for a reason.

bondosgto

Bader-X

iTrader: (2)

www.texas-speed.com {--- 454 LSX available since a long time ... they usually have some that is already built ^_^ maybe you can get a good deal if you send them your block?

their ported LS7 heads are great to

2000_SS

iTrader: (24)

My 454 was build by HKE, click the "build thread" link in my sig for more info.

It's a 4.185 x 4.125 combo. some guys go 4.200 x 4.100. It's a perfectly fine setup with the right custom piston in it for a NA application. If you plan on spraying much nitrous or adding a blower, you'll want to stick with a 4" stroke and smaller bore, like a 434 or 440.

03supercobra

iTrader: (38)

I had a 454, but that didn't work out well. Now i am doing a 4.200 bore, and a 4" stroke with 6.125 rod. It will end up being a 443. From what i have been told is that the cylinder length is really short in the LSX block, and the 454 setup is pushing it if you are going to run any power adders. A 454 sounds cool, but i would rather have a better rod ratio, and be able to spray the 300's if need be.

LSX350Z

In the current 09 GMPP catalog you will find the LSX 454 crate engine and a 454 balanced and forged rotating assembly along with three choices of LSX blocks. Why are some people coming back with reliability issues with the 454 displacement? These blocks are marketed up to 482ci or 500ci potential by GMPP depending which LSX block you go with. What issues will arise if you go 454 instead of 440ci? It doesn't seem like that big of a difference. My goal is at least 650rwhp on the engine.

davidws6

iTrader: (36)

I went with a resleeved LS2 block as I did not want to stuff an additional 100 lbs on the fornt end. + The sleeves are longer to support a longer stroke. There's more power to be had, ie, Nox, etc. but staying NA to hopefully extend the life of the engine.

The heavy Iron block should hold up to anything !!!

2000_SS

iTrader: (24)

Like stated above, they have pretty short cylinders (short deck anyway). The downfall can/will be the piston design. You need to have an experienced builder customize the piston in a 454. With that stroke/cylinder length there are issues with the skirt coming too close to the bottom and rocking the piston. Because of the necessary piston design, you'll lose a lot of the meat on top to make power adders safe.

LSX350Z

Below is some info on the block I am using. Even though its a tall deck block you still see issues with the skirt coming too close to the bottom?

19166097
L SX Tall Deck Block
• 3.990" finished siamese cylinder bores (ready to be
finish-honed)
• 9.70" semi-finished standard deck height (ready to be
decked)
• 4.50" maximum stroke (small base circle camshafts
required)
• Capable of 364- to 500-cubic-inch displacements or more!
• Orange powder-coated finish
• Accepts all LS and LSX Series heads, cranks, cams, etc.
• Approximate finished weight is 250 pounds

03supercobra

iTrader: (38)

Thanks for expanding on what i said, it makes more sense the way you worded it. Sick build BTW

Why are you using a tall deck? Are you wanting 650 at the FW or RW?

LS6427

iTrader: (2)

Thats a "tall deck", it can go beyond 454ci as far as longer strokes because its a tall deck. Ain't no way you're gonna build a 500ci or a 482ci with a "standard deck" block. It'll be a ticking time bomb if you do.

Even with the tall deck, it would be smarter to stay well under 500ci. Like a 462ci. 4.185 bore x 4.250 stroke. N/A only.

Spray...438ci (4.125 bore x 4.1 stroke). Make 900+ RWHP on a 300 shot. It would be sick fast.


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LSX350Z

Initially I thought there would be better connecting rod clearance with the stroker cranks and overall more versatility. 650 rwp is the goal.

LSX350Z

What would the static compression for 900+rwp on the spray be? I don't want a low compression slouch. 650rwp at the engine is the standard.

LS6427

iTrader: (2)

11.3:1 should be fine. You can still make great N/A power like that, certainly 600+ RWHP.

What intake you gonna use?

What heads?

Those two things will dictate what your N/A power potential is gonna be.
Yes, I know its the complete combo, but the top end is everything.


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2000_SS

iTrader: (24)

x2. Top end dictates horsepower 100%. 650rwhp will be easy with a tall deck and efficient trans/rear end. A piston with a large surface area and a high-flowing head/intake will be STUPID fast. My setup will be breathing down 650's neck if i can afford the ITB intake i want.

all it takes is money

LS6427

iTrader: (2)

cough "harrop" cough...........

Bad ****.


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LSX-PWR

So the tall deck block is already being sold on the market?

tektrans

iTrader: (23)

my question as well. Warhawk has one out already 4k+