Speaking of the block itself with factory sleeves. What is the reliable power limit of the block?

 

Detoxx has been running his at 900+whp for a while now and keeps turning it up and its a SBE.

 

The LS2/3 blocks seem fairly reliable under 1000, fuel it right and don't get greedy and it'll reward you. I ran 30psi on my stock one and only thing I finally broke was a ringland on the SBE, threw forged rods and pistons in it and kept rockin.

 

I’m speaking of just the block itself. I have forged rods/pistons curious at what point the block becomes the limiting factor.

 

I’ve been making over 1000 for a couple years got it up to around 1300 still no issues

 

What the details of your combo? Mounts or motor plate?

 

Sbe ls3 s491 30psi still using regular mounts at this point but I am planning on switching to motor plates

 

I haven't seen any info on anyone pushing LS3 to failure. One way to find out though... build one to produce 2K hp. Half fill, stock stroke CCW crank (to minimize block stress), rods and pistons, 3/4" thick deck heads, 1/2" head studs and Clark copper head gasket w/ top fuel hoops, motor and mid plates, M1 fuel and turbo to 45psi. Check it out every winter to see what the mains look like and check bores for irregularity.

 

LOL...I don't plan on going that far at least in the near future. Just thinking about going from my current D1x to an F1a-94 so maybe 1100 rwhp. The procharger puts different stresses on an engine than a turbo. I just wanted to check if the block itself has a reasonable chance of lasting at that power level.

 

Exactly, mainly the ones I see blowup are with blowers that wipe the front main or snap the crank

 

Can't imagine there's a set number? or even close range? All depends on the loads placed on it and when. I would have guessed most centri blowers aren't making big power till upper RPM anyway, that they'd be pretty forgiving. I'm sure a factory motor mount 3800lb setup VS a 2700lb motor plate setup would have wildly different failure points. I believe Kurt Urban mentioned factory cranks factory blocks for the most part are pretty similar in strength. (aside form forged ls9/ls7) Mains showed quite a bit of movement around 1200 crank. Not that people have gone far over that... but if its wiggling all over hell I wouldn't call it reliable.

 

Understood...Just looking for a ball park number on the block. I'm running a D1x at max recommended impeller speed now. Although it probably has more in it (boost is steadily climbing all the way to shift and IAT was only 10 degrees over ambient). I'm thinking I'm only going to keep wanting more. I wouldn't take this engine past an F1a-94 so maybe 1100 rwhp through the auto. If I ever want more than that I'll have a different block for sure.

 

Yes, belt driven blower is the opposite end of the spectrum (block stress wise) than a turbo setup that I posted. Other than crank drive, not sure what it takes to minimize the stresses induced by a belt driven blower. I would think a billet CCW crank would be a significant benefit if pushing a belt drive unit.

You could always go turbo(s) when looking for that 2K power. JK!

 

LOL...I'm very happy with procharger. "If" I ever want and have the car built around 2k power then I would still stay with a procharger, but it would definitely be crank drive. I may never get to that point. A year ago I didn't think I'd ever want more than a maxed out D1x either though.

 

All these fast SBE's crack me up !!

It really does make you wonder why bother building anything when they survive so damn well.

 

I honestly never expected it to last this long or go as fast as it’s been

I’ve had a forged crank and rods for over a year waiting I just don’t have the heart to take it apart it runs that well

 

I’ve seen a few break cylinder wall at deck surface.

 

Care to share details on config and likely cause of failure?

 

That is the weakest part of the block.... Hence why they break there

 

Just depends on the goals! Everyone's happy with 600 when they start! Then 5 years later they are trying to double that on JY setups in cars that have no business going that fast!

I agree, there's a point where you shouldn't even bother with a factory block build. When talking basic drag racing though... what kills me is all these guys throwing away money on stroker cranks, rods, and big bore pistons doing "half builds" with a stock blocks. The block and factory crank are pretty well matched in terms of peak power. Replacing one without the other isn't doing you any big favors. From what I see, these types of "half builds" are in and out of the cars just as much as the SBE stuff, if not more. And when they come out, you know that machine shop bill is going to be 3x more than another SBE small bore motor. Then you have to wait 3 months to get the damn thing back. I can buy 6+ SBE 4.8 motors for the cost of a "forged internal 408". In my experience "built motors" are often put together with machining that's very poor in comparison to factory GM machining. .

I'm constantly at the track, since it's 6 minutes away. So I see a lot of these half built and SBE setups. The built motors are in and out of the cars just as much as the SBE stuff, and the down time is always massive. If you can meet your ET or chassis cert goals with an SBE, why "build" a motor? I'd rather have a $500 SBE short block on stand by I can swap in a day, than be tied up waiting on machine shops and big bills. There are SBE guys getting multiple seasons running low 5 sec 1/8th and 7 sec quarter miles. Sure, that's pushing it... but if the goals running a 10, 9, 8 sec pass for the typical street/strip car, the SBE small bore stuff *should* do it with ease. And if your breaking the SBE stuff at those levels, you're doing something wrong and would likely break a "built motor" too. Better to experiment with "disposable" power plants IMO. It also takes a lot of the cost anxiety out of racing. I'm not nearly as worried about breaking a SBE as I'd be with a big $ long block.