Reverend Chaos

iTrader: (1)

sorry, tried search and it's not working.

But like the title says, what is the upper limits of a stock aluminum 346 LS1 that has a fully forged rotating assembly before cracking/breaking etc...

pist0lpete

iTrader: (3)

Your limits will come first in a boosted application where that can be solved with expensive liners. You should be able to handle quite a bit of nitrous as well. There are people making north of 1000 hp on stock aluminum blocks and I have yet to hear of a proven block failure yet other than cylinder wall distortion at high boost levels.

orangeapeel

iTrader: (18)

slow trap

iTrader: (22)

i would think anything north of 700 rw would be pretty high boost,well if you call around 13 + psi high boost.hasn't some people had bearings that looked like they had been beat to death with high horse aluminum blocks ? i'm still on the fence about the iron v/s aluminum.
someone school me

TNTramair

iTrader: (15)

subscribing?!?!...school me too.

carado1984

first of all the density of aluminum is less than the density of iron.. If someone can find out what type of aluminum the ls1 block is made use can use this.. therefore you should be able to put more boost, or port it more while maintaining strength.. the question is if a forged 346 can handle 1000hp and a forged 6.0 can handle 1200, but youre only giving it less than 1000 does it matter.. well heres the difference in density's of the metals..

Metal Aluminum 2.643
Metal Aluminum bronze 7.702
Metal Aluminum, 2024-T3 2.77
Metal Aluminum, 6061-T6 2.7
Metal Aluminum, 7079-T6 2.74

Metal Iron, Cast, Pig 7.207
Metal Iron, Ferrosilicon 6.984
Metal Iron, Spiegeleisen 7.496
Metal Iron, grey cast 7.079
Metal Iron, wrought 7.658

Im sure i didnt help anything by posting that.

slow trap

iTrader: (22)

i know about properties of metal,i'm a machinist. i'm needing schooled on why some people think around 700 or so is all they would run on an aluminum block and some feel safe with 800+. i know the bores distort but at what hp levels is the million dollar question. i know different setups will change but i would hate to have say a 750 rw aluminum block that the bores are distorting and having sealing issues when i could have just got an iron block with a tubular crossmember and upper & lower a arms that would weigh very close to the same for just alittle more money.i went with the 408 iron because i am not worried about an extra 80-100 lbs on the nose without the tubular front end pieces but for a racer i can see why you want the lighter block but at what hp level it becomes unreliable is the question.

Reverend Chaos

iTrader: (1)

Exactly my question as well, I don't plan on being anywhere near over 800 or 900rwhp, but with so many going with the iron block for strength reasons, I'm wondering at what level is it really necessary to have that extra strength?

I'm only planning on a fully forged 346 turbo'd stock block in the 600 to 700 crank hp range. reliably and somewhat street friendly. I think I would be happy with that and call it a day. (think is the key word lol)

so would an iron 6.0 just be more of an ease of mind type of deal at those levels?

30thta436

iTrader: (10)

The only block failure from to much power that I know of is from Hardcore. They had one of their fast cars with a blower break the main webbing down by the main caps. I think their horsepower level was around 1200-1300. They made a main stud girdle tying all of the main caps together. I think they are even higher horsepower now though.

I know of several Aluminum blocks with 750-850 RWHP. One is a nitrous 427 that makes over 900RWTQ.

ChaseSS

iTrader: (17)

i think the material of the block is 319 T-5 aluminum

PREDATOR-Z

600>700? Stock block can handle that all day long.
Stock crank as well, might want to nitrate it just for giggles.
IMO get the lightest rod your money can buy & forged pistons with pressure reliefs.
9.0:1 SCr and you are good to go.

Reverend Chaos

iTrader: (1)

thanks, I knew it can handle that power level. just wondering why so many are going for the iron block when they are staying at under 800hp levels? room to grow?

PewterZ28

iTrader: (1)

Anyone care to guess what the stock bottom end can handle? I'm at about 500 fwhp right now but I'm planning on being at 700 to 750 next year.

carado1984

i think its hard to answer this question because most guys running turbo setups that big are running stroked motors.. theres a guy with a MRM ta convertable, non ram air.. i believe hes running a 346 around 750 rwhp.. i think you should be safe on an aluminum block up to 1000 rwhp.. being that iron is stronger and the block is thicker, im sure a few hundred more would me a safe bet.. Truthfully i would be worried more about the internals blowing apart and damaging the block than the strength of the block itself..

carado1984

the crank is good to im guessing around 7-800... a buddy of mine on here has a c5 a4 with a twin sts kit running 500rwhp.. his name is sam98ws6.. people blow motors with less power than you have and some run 550-600 stock bottom end but they could just be babying the cars.. i would say if your above 500 and you like to redline it that you should probably go forged.

Hennytime

iTrader: (33)

thats the difference between a decent tune and a baller tune.

carado1984

well i know he installed or did partial installation with mikey at rapid but i think he did most of the work himself and he tuned it himself with hp tuners and the help of a dynoshop in dillsburg pa.

Reverend Chaos

iTrader: (1)

Yes I plan on forged rods and pistons, keeping stock crank and block. like I said only planning on 700 at the crank max with a moderate turbo setup

chriswtx

iTrader: (5)

You will be fine. I plan on seeing 750rwhp with my aluminum LS6 block.. Several others are running 800/800rwhp on a forged 346 without problems...

BIG BAD BLACKSS

iTrader: (4)

People have seen 700-750RWHP with similar setups to what i want to build, and id like the option of a little nitrous or a bigger blower or turbo later down the road. So i went 6.0 iron.