I see a lot of the big number guys (near and over 1000hp) are running LS2 blocks or the LSx iron block. Will the stock LS1 block not handle 1000hp, even with a forged rotateing assembly? I know you can't go much bigger than 400ci on an LS1 block but that should be enough... Can anyone help me out here?

 

Well you can go pretty high but when the blocks like the LSX are coming out and are rated at 2500hp why would you stuff $5k worth of internals in an already used block... Out of all of the LSx blocks out there the LS1 is the weakest... Still incredibly strong considering that you can't take a SBC as high as you can an aluminum block LS1... Also, I believe in the notion of doing once and doing it right... With the newer block 400ci+ is much easier to attain because you're not limited by a 3.9xx bore... The answer a couple of years ago was to sleeve the block... That's fine but when FI comes into play that means things are gonna be tested and some of them didn't like it.... Plus if you look at the price of doing a MID sleeve it cost as much or more than some of the much stronger blocks coming out... I think it's a obvious answer... You CAN build an LS1 for cheaper but in the long run when a rod/rods, pistons, crank, cylinder wall, or something else breaks because you chose to opt out a little money then the little bit of money becomes BIG MONEY... This is just my perspective and the reason I'm not even considering anything else besides the LSX block...

 

Nicely put. /thread

 

I think that depends a lot on how much power you want too. If you only want 750 rwhp theres no reason a built 346 wont handle it but yes a bigger cube ls2 will make that power more easily.

 

I agree with you whole heartedly but he's asking why more people aren't trying to push the LS1 block up to and past 1000rwhp... The down and dirty answer is reliability.. People used to when they HAD to... That was before the LS2, aftermarket, or even the popularity of the LQ9/LQ4 blocks...

We also have to remember that the LS/GenIII engine is an animal of it's own.. It took quite a few years for any available aftermarket support ... I mean I hear guys like KP talk about having to use a FMU with his Procharger and cringe because of how good we have it.. For example we couldn't even tune in Speed Density (without fudging stuff here and there; talking about the average shade tree mechanic) until like two years ago.... Two years ago was pretty much 3 years after the end of the Camaro/Firebird and if you want to look at when they were produced it was almost 4... Most cars are produced 6 months to a year before their actual "production year"... Now this being said think about why more people haven't pushed the envelope with the GenIII engines... It was because us GM guys were behind the curve for aftermarket items and could only do so much with the factory pieces... We were in the same or worse boat as the LTX guys... Those parts when they first came out pulled a premium too and they are pretty much the same design as the Gen I SBC..I know some of the older guys here remember when there really weren't any aftermarket heads.. Companies were charging like $2k just for ported/polished heads with either stock size or 2.02 valves... it's just the fact that things take time... Also think about how much better we do have it.. How many early blue oval 4.6 guys were pushing their engines anywhere near 1000rwhp... I realize the 03/04 engines are different but before those the engines weren't even close to ours IMO... I'll get off of my soap box now...

 

KP just went 8's on a 346 ls1. I'm sure he's pushing 1k

 

very well said-

 

Well thats exactly what I wanted to know, till I can afford to do it right I'm going to stay cam-only on nitrous.

Thanks guys

 

You just need the RIGHT ls1 or ls2 block, we run over 1500 at the crank all day with no issues other than the 4 bolts holding the heads down. Visit ERL performances web site to see their supper deck re-sleeved ls blocks,the prices are very competitive to what an lsx will cost you and you get to keep over 100lbs of the front of your car!!

 

Around 1000 flywheel probably, but I have had this same short block in the car now for nearly two years and I'm coming up to the 340 pass mark which isnt bad. I usually run this thing at least every other weekend and I'm not afraid to make 10 passes a day with it if I have to. Most of the passes I make are more in the 9.20-9.30 range so I'm not beating it every pass but lately the F1A has been on here at 18-19psi peak.

So needless to say its holding up pretty well, compression/leakdown is still good (plain old speed pro moly rings), oil pressure is the same as the day I fired it up and you dont see it pouring blue smoke out during a pass. I'm very curious to see what the rings, bearings and piston skirts look like in this thing, I have detonated it a few times I'm sure over the last couple years so it will be interesting to see what everything looks like in there. Honestly if I wasnt paranoid I would run this engine for another year, I think its just getting broken in

But most guys just want the most CID you can get for the money and in the big picture a LS2 based 402 makes a lot more sense then building a nice forged 346 these days.

 

If you have a choice, the LSX > LS2 > LS6 > LS1.

 

In my opinion LSXERL LS2

 

Do you have anything special in the block like a main girdle or billet caps?

 

Nope, arp main studs, thats it. Was a brand new block though, its the later one with all the short head studs so it may be stronger then the 'old' style LS1/LS6 blocks.