Originally Posted by Malaclypse

What Does a 625+ WHP LNF Look Like? - Cobalt SS Network

600+ on a stock bottom end. Probably wasn't sustained for long. I'm sure they're going for more power out of it, too.

Originally Posted by Boosted4

Well you should do a search and look at tons of threads, it varies depending on what turbo kit and tune. A safe limit is probably 420-450whp. ZZP and others have put down more, but then you start running into issues such as bending rods and stuff.

Originally Posted by Malaclypse

What Does a 625+ WHP LNF Look Like? - Cobalt SS Network

600+ on a stock bottom end. Probably wasn't sustained for long. I'm sure they're going for more power out of it, too.

Originally Posted by Matt M

A couple hundred dyno pulls over 400whp. Probably 100 or so above 500whp. About a dozen pulls at 600+.

Originally Posted by Matt M

I took this motor apart yesterday. Here are a few more pics-

Notice that rods 1, 3, and 4 don't look bent much if at all. They looked worse on the previous engine that made about 100 less HP. I have a couple theories as to how this could be.

Originally Posted by Matt M

When we first tested our ported head, we had a motor out of a roll-over parts car that we bought. We ported the head and bolted it back on that motor and then swapped the whole motor into my car. That was the motor that ran the S256 a couple years ago. It had a handful of dyno pulls in the 500whp area and one pull turned up a little that hit 530, although the fuel system wasn't supporting that very well. It was 3000 psi on 110 octane running at 13:1, FWIW. Late that year, there was a little smoke coming from the exhaust. We tore everything down to see what was holding up and what wasn't. We found that the rods were bent with a couple being pretty bad. This was after running the 256 for a couple months with 30-40 dyno pulls and 2 trips to the track. At that time, the original motor out of my car went back in along with the stock head. The first time this motor was in my car, it had over a hundred dyno pulls and about 8-10 track visits. This time around, we used this motor to test the S252 turbo kit, which saw a couple hundred dyno pulls and 4 or 5 trips to the track. We also ran the stock turbo for a while testing E85, zzp cams, and some other parts. This setup had over a hundred dyno pulls, and one trip to the track. We then put the Z254 turbo on and did a couple dozen dyno pulls and a bunch of street testing. After that, it got the S259 turbo which saw a few dozen dyno pulls while testing various cams and fuel system upgrades. Between the Z254 turbo and the S259 turbo, this motor had dozens of dyno pulls higher than the other motor ever made. Max power was nearly 100 hp higher, and the max torque was about 100 ft lbs higher as well. Having said all of this, it would stand to reason that the motor that just came out should have severely bent connecting rods, but it doesn't. My only explanations are that the S256 setup was being revved to 8200 RPM, while the other setups were typically maxed at 7500-7800 RPM. Perhaps more importantly, thinking back on how the previous motor came out of a roll-over car, there is always the possibility that it was hydro-locked on motor oil. If it stayed running for a few seconds while upside-down, I could see this happening.

Anyway, these are my findings. At this point, I don't feel that the factory rods will be an issue for anyone running in the 450whp range with occasional 500whp hits.

Originally Posted by Boosted4

Thats what I said

Originally Posted by T-Man

Not everyone is going to search for more info and is going to automatically accept the crazy hearsay that runs amok on here. Then we're going to see 50 new threads pop up with all kinds of search-able content that has been covered a million times and beat to death.

To make you feel better, yes, you sure did.

I just made it even more dummy proof