curtains

OK so I tried doing some googling, but most of them just regarded stock blocks etc ..

Anyways what I want to know is how much can an aluminum LS1 BLOCK itself can handle before it starts degrading or warping etc as internal wise I plan on getting forged internals(at some point) so they'll be pretty much indestructible and nothing to worry about when thats done.

I plan on building a twin turbo LS engine, and the displacement of a LS1 is more than enough I know LS2 is a stronger block and the LS3 is a much stronger block yet again, but I don't really want to have to buy a LS2 or LS3 if I don't have too as the price difference can be a bit, well LS2's not too bad but LS3 is definitely a big jump in price as there are not many 2nd hand ones around or people want lots for them or there expensive new.

So I want to know how strong the LS1 aluminum block is, the goal is 600rwhp (maybe more when i reach the 600mark but for now 600 sounds like a good target for now), but i want the engine to last for a very long time without warping etc, and once I spend the money on forged internals I don't want to end up having to buy another block or have to start on building a new LS2 or LS3 cause I didn't do my research.

I know alota people will say or think, just spend extra money to buy a LS2 or LS3? my answer to that is, if the LS1 is capable of holding my targeted power range without degrading then why spend the extra money on a LS2 or LS3? I don't need the extra cubi's + i can always stroke it if i really wanted more cubi's.

jb7241986

iTrader: (4)

I once read an article where a fella had over 1,000 rwhp in his trans am on an ls1 block......if you arent sure id go 6.0 adds a little weight but a tubular k member and a arms along with some weight reduction will help that

Avengeance

iTrader: (4)

LS1 block will handle 600rwhp no problem. Mine does... and it still has stock lower bottom end. FWIW it gets put through its paces when I use it. 14psi.. raced frequently.

If youre building it just use the good internals with ARP hardware and I dont think youll have any issues at all with that goal. As with any build just make sure your tune is good as well.

jason02Z

iTrader: (10)

all arp hardware and rpm's under 7k. pinned billet mains and engine girdle.. but that extra cost is what u would would need for the ls2/3.

gnx7

iTrader: (28)

Start out with an LS2 block. They have stronger sleeves that aren't prone to getting out of round with a high HP street setup like an LS1 block can do. Supposedly with 3-5K miles of street driving the LS1 with high HP forced induction will lose ring seal. The bores simply need a quick hone to get them round again and new rings... and voila. Good for another 3-5K miles until it can happen again.

LS2 block is a bigger bore which allows for a better cylinder head selection/larger valves and less shrouding. It also has better crankcase design for more even pressure between cylinders. If you have the money start out with an LS2 block if you plan to make more than 600rwhp or so. Plus it will have better resale value down the line.

Only thing most high HP builds do with the block is to pin/dowel the main caps to prevent them from walking around. At about 1000rwhp is when the 4 bolt head design becomes the limiting factor and you can begin to push coolant. Beyond that power level is when the cost to do becomes cubed

A twin turbo LS2 with stock bore/crank would make 600rwhp with decent turbos with only a couple psi. You should look into maybe doing a single turbo as it is less complex and less costly and easier to package in the engine bay.

NoGo

iTrader: (2)

Sleeved LS1 block here.

Almost 30k miles at 700 HP. You shouldn't have any trouble with your target power on an LS1 block.

Go stock crank, aftermarket rods, forged pistons, ARP stud the thing and it will hold without any issues.

Beaflag VonRathburg

iTrader: (176)

Back in the day you have to consider everyone was running either an LS1 block or a 6.0 block. Harlan went mid - low 8s on a stock LS1 block and crank with twin 67mms. It can be done and I think people underestimate the LS1 block a lot. They can be had pretty cheaply if you can do some searching and I wouldn't mind having a spare one to build something with.

KissMySSo1

iTrader: (2)

I read about people saying how much better the LS2+ blocks are and other people say ohhh don't use an LS1 block they're weak. My car has made 1200+rwhp with a stock LS1 block without issues. No dowels, no girdle, no billet caps, no block filler and stock sleeves.

Personally, I think that the people that have had "crank walk", or bearing issues was due to incorrect tolerances. (That's what causes bearing problems!!)

How about the following question... Not including head gasket issues. Not talking about piston/rod issues, but....

Who has ever had an LS1 block fail on them???

FMX05

iTrader: (3)

Very few people

The Fugitive

iTrader: (6)

the LS1 block is a good block but keep this in mind if it was perfect there wouldn't be any LS6, LS2......LS7 blocks, minor changes have been made to make a great block better and with more cubes. That being said it is better to do it once and not have to worry about it again also remember with the more cubes you wouldn't have to run a lot of psi to make it to that power so less stress on the internals so when you want to turn it up there wouldn't be a second thought

LS6427

iTrader: (2)

GM also screws things up as they go too.......

Actually, the LS1 block is stronger than the LS6 and LS7 blocks......especially if you're talking "resleeve".

The LS1 for strength, I think is the strongest of them all. Perhaps the LS2 was made stronger overall, not sure.

Steve @ RED posted a bunch in a thread in the 1st Gen Engine section talking about this very subject. The LS1 block is STRONG.........

.

Bob@BruteSpeed

iTrader: (16)

Twin turbos at 600 to 1000 rwhp, I would not think twice about using an LS1 block. You should have no problems with it if properly built. Bob

2nd Gen Fl 'bird

iTrader: (13)

I feel that aluminum blocks of the past did have durability problems due to the aluminum compounds being used at the time. That said, it's hard to shake the stigma of the problems. Modern day blocks have come a long way and the engineers have produced a better, harder aluminum. I do agree there is a breaking point for these blocks and should go iron but, I doubt there are but just a few on this site that are bad asses and need the iron/after market blocks. Build what the budget allows.

gpr

iTrader: (6)

What is required to build a ls1 block properly for that power level?

curtains

I thought I posted a message yesterday, but i guess it didn't show up.

ok sounds good, LS1 should good for me then, I don't plan on much more power than 600rwhp.

Bobatsuperior

iTrader: (14)

subscribing

Bob@BruteSpeed

iTrader: (16)

Block honed with torque plates and ARP head studs is really all it takes, other than making sure you use a competent machine shop who does align bores, etc. Bob

96 Comp T/A

iTrader: (8)

PiggyBacking on the conversation, how does everyone feel about 1/2 headstuds in an aluminum LS1/LS2 block? Can you get enough clamping force out of the block with the big studs or does it flex up in the 1000+ range? I want to go their next year... Trying to decide to keep investing in the LS2 that I have or pick up the GMPP block or RHS. By the time I have it sleeved, pin and add billet mains, and possibly machine for bigger head studs, it may just be time to step up.

Vetal

iTrader: (3)

What would you do with stock (or Patriot, as in my case) heads flexing at 1000WHP? Or shouldn't they?

Bob@BruteSpeed

iTrader: (16)

Sell the heads and go with heads with thicker decks. AFR, Trick Flow and RHS make heads that will handle 1000 rwhp without pushing water. Bob