Eagle02

iTrader: (20)

Bores are at 3.907, ARP hardware throughout, Callies rods, Wiseco pistons, 10.5:1 CR, plenty of valve spring to support the cyl pressures, plenty of fuel system, AIS meth kit onboard, IATs <100, current boost @ ~19psi.

How far have the aluminum blocks been pushed without imminent failure?

Eagle02

iTrader: (20)

I see 0* KR right now. But just because KR isn't happening doesn't mean I can just keep pushing up the boost... right?

dschmittie1

iTrader: (64)

Fireball made some where around 1700 hp enough to run 7.99 with his Aluminum ls2 granted it had pinned mains and was a filled block. but that was when he lost a stock sleeve.

ls1curt

iTrader: (31)

I've been 8.7@157 at 3450lb with a stock ls1 block

Camper

iTrader: (1)

he asked max boost.... comprehension ftw.

skinnies

iTrader: (33)

28lbs on a few combos

Fireball

iTrader: (21)

IIRC I was generally pushing about 34psi on my LS2...about 1700 hp give or take....sleeve finally cracked.

Fireball

iTrader: (21)

Easy there cowboy!

FYI, max boost = meaningless LOL. 20psi with killer heads makes WAAAYYYY more power than 20 psi with stock heads

power is what breaks stuff....mph indicates hp.

stevieturbo

How fast other alloy blocks have been pushed mean little as to how much you're bored to the limit LS1/6 block are pushed.

There are several block/liner combos and each will have different strengths. But from the bore size you mention I assume you have either LS1/6
And you also dont say how much power you are making, boost is irrelevant other than the potential for detonation.

But the simple fact your liners will now be very thin, isnt a good starting point.

Eagle02

iTrader: (20)

Thats good news...

Yeah, I've heard 25 is a good #, 28 sounds even better.

I'm just below 20psi right now, 16* timing, zero KR.

Yep, LS6 block. Haven't dyno'd the car, but it trapped 170mph in a 1/2mi drag last weekend. I know that doesn't help much... lol

I need to get the car back on the dyno, but the local shops are busy as hell. Next appointment isn't until July.

Finally, I wasn't under the impression that a fresh 3.907 bore was all that far out there. Other threads are saying 3.915, 3.910, even 3.908 ok as max bore sizes.

Quite simply, I'd thought about pushing out to ~25psi to achieve the best ET this combo has in it, then detune it a bit. I don't want to kill it this early in the year!

stevieturbo

I would say very few push a stock LS1/6 block past 3.905", especially with boost.

All you can do is take your chances. People have bust them with less power and boost. Or all it might take is some detonation

If you absolutely trust your knock sensors then all good and well in that respect.

Eagle02

iTrader: (20)

Yep, my knock sensors have not lied to me in the past. I keep em around just for that reason!

R_trim 93GT

iTrader: (1)

Impressive, that calculates to over 1000hp. Any other details on the combo?

• Type of power adder
• Fuel used
• Compression ratio
• Stock block, or stock block, crank, rods, etc.
• Stock heads and head bolts

I'm currently at 20 psi and almost 900rw on a cam only 85k mile LS1 with twin turbos. I'm trying to figure out how much more it will take.

Eagle02

iTrader: (20)

That's exactly what I was looking to determine myself. Going to take her to the track and just start working my way up and checking the tune each and every pass.

* PT88
* 100 + 50/50 meth
* 10.5:1
* stock block & crank, forged rods & pistons
* reworked 317s, ARP studs throughout

ls1curt

iTrader: (31)

Thanks. s400-hp88 turbo, 93+meth, 10.4:1, stock ls1 block, forged crank, rods, pistons, 317 heads w/ studs

R_trim 93GT

iTrader: (1)

Thanks, man. I found one of your threads where it lists the setup. Very good numbers with a lot of stock parts. This looks like a good indication of what is possible. What kind of air fuel ratios were you seeing? I made 3 test passes on 20 psi at 10.6:1 AFR. I typically run 11:1 AFR on 18 psi.

VINCE

iTrader: (1)

Didn't Harlan run a 346ci to 8s at 170mph years ago????

SKULL

iTrader: (7)

he had a 6.0 iron right? (harlan)

ls1curt

iTrader: (31)

I think Harlan went 8.3 on an aluminum ls1 block, not sure of his weight though.

Bob@BruteSpeed

iTrader: (16)

With your 317 heads, more than likely you're going to start pushing water at 20+ psi. Bob