Y2KRoadster

Greetings.

I did a search and didn't really find anything definitive.

I've been looking at a few C6Z's for sale (only ones with the heads addressed and cam/boltons added) and have seen the power levels range from 520-600+rwhp on the stock bottom end LS7. My question is, how tough is the stock block, rods, rod bolts, pistons, etc. This is assuming the tune is good and the compression isn't crazy. Pump has only...no meth, no E85 (from the cars I've looked at). Thanks!

-Brent

rio95

NA power is not a concern. Add over a 100 slot of nutrous and it gets a little risky. If boosted 700 or so is typically fine. I think the weak link is the sleeves. Replace those along with some pistons and hardware and you can push a lot further.

Y2KRoadster

Yeah I was thinking that a N/A car 580-610whp shouldn't be a problem but I don't have a lot of background experience with the LS7 besides a few things here and there. I had an 850+whp C5 that I sold a while back and want to go N/A now. Thanks for the info!

RenoC6Z06

SHovV

A turbo car just made 850+ I believe and there's a supercharged and nitrous that made 940ish on a completly stock bottom end. Sheer cylinder pressures aren't the issue, it's preignition type issues that cracks sleeves and pistons.

Y2KRoadster

Yeah I agree. I was just curious if a well tuned N/A car making good power can last a long time (20K+ miles). I should have been more specific!

meinersk

600rwhp you will not hook 1st gear on the street..even 2nd tough...if i wanted more i would look at forged engine cars for sale...i seen many push to 700rw stock bottom...

Michael_D

Detonation, cylinder pressure, and rpm are all things to consider when pushing oem engine components beyond their design. Detonation is a killer of pistons, cylinder liners and rod bearings. It will take out an engine pretty quickly. Cylinder pressure can twist rods, and as it is increased, makes detonation more likely to occur. RPM increases cause things to fail with change of direction of the pumping parts. Imagine yourself bungee jumping. It's not the fall that's scary, it's when that cord snaps at full stretch that kills you.

So what's the limit??? Don't think anyone really knows. The Ti rods are the big mystery. There just aren't that many titanium connecting rods being used to fully understand what these can handle. The pistons are good, but they are cast. Cast hyper-U pistons hold up quite well, but do not hold up to detonation like forged pistons do. They are brittle, and less forgiving. The crank is hell for stout, and can probably handle 1000 hp. The cylinder liners are a thin, cast iron type alloy. Not a great alloy either. The rod bolts are also questionable if rpm will be increased.

MTIRC6Z

I've got LS7 ti rods with ARP bolts in my 388cid CTS-V pushing 800+ rwhp...so far so good. I do not loose sleep over the ti rod strength or lack thereof.

BTW Michael, did you know that "falling feels like flying until you hit the ground"

Couldn't help but think of this quote (from the band Hinder) when I heard about my buddy loosing the tail of his experimental high performance airplane. http://abc7ny.com/news/plane-practic...-pilot/960733/

Cheers, Paul.

Josh B.

Depends on N/A or power adder. Blower cars contend with torsional loads on the crank that are not seen by N/A, Turbo, or Nitrous cars. Blower cars need to develop the power to turn the blower, with the accompanying heat and cylinder pressure, so a 700rwhp centri car burns more fuel and has generally more cylinder pressure than a turbo car due to this fact. Nitrous increases cylinder pressure more suddenly that other power adders, which can be damaging to the cast pistons and rod bearings. LS7 is pretty stout for what it is. Beyond 700rwhp, I would say you are tempting fate. Maybe 750rwhp with a consistent diet of race gas to insure against detonation.

Y2KRoadster

Thanks for the input guys. My biggest concern is longevity....with the setup being on pump gas and a good tune. My last car had over 40 hours of tuning time on it and ran perfect.

Will an N/A C6Z with 580-600whp on pump gas last 30K miles? How often should the heads be inspected? Assuming that the heads are, say, WCCH with new bronze guides and all the other goodies. Of course, this is also assuming the car has a great tune and never gets tracked...and is mainly used on the highway.

Thanks again fellas.

SHovV

Too many variables subject to too many opinions to say the least...

Y2KRoadster

Thanks for your input but I fail to see why you would say there are too many variables.

I listed the power level, the tune, the type of driving, the head issue, and the type of fuel used as this is the type of car I am looking at buying...and many people on this forum own cars exactly as I have described. I am well versed in all the physics involved when it comes to pushing the motor as well as how to properly tune a car.

I am simply looking for real world experience by those on here who have similar cars that do not take them to the track. Don't think too much into it.

Y2KRoadster

Try hooking when you're at 1000HP.

Thanks for the info. I did most of my in depth learning when I bought my first S/C C5 a long time ago. I recently just sold a 1000 HP C5 (YSi car) and had the tune spot on.

I am simply looking for guys that own h/c/i 580-600whp Z's to share their experiences...mostly the guys that have been running them for a while. It is impressive that a recent Z just went 940whp on the dyno...but that is completely different from what I am asking. My buddy owns the stock bottom end record for any other motor besides the LS7...pretty amazing what a good tune will do!

Y2KRoadster

As stated in the title and in the description, I am only talking about N/A cars 580-600whp.

SHovV

Well, personally I don't see why a 600rwhp highway cruiser wouldn't last tens of thousands of miles. I guess it'd be solely up to your discretion as to how often the heads need to be checked. Every 10k miles? Never?

In my opinion, one could assume and speculate all day long. But at the end of the day who really knows?

Y2KRoadster

That is exactly why I posted this question. There are people out there with real world experience. They would know.

Michael_D

You will be fine at that level N/A. It is at about 750 crank hp, or exceed 7500 rpm that you start treading water with the OE short block. Valve springs will require routine testing, depending on lift. At the 580-600 whp level, lift will be .650 or higher, generally speaking.... You would be better off talking to engine builders with experience with this engine, who are not to be confused with Tooners and bolt on guys.

meinersk

I have 589 and 560tor...id say n/a pretty reliable at these levels...but i am 200 crank over stock so much less reliable then stock...before i bought mine i was not able to find many modded n/a failing.....