nightmare2012

I have a 2012 camaro with a H/C/I LS7 with a holley hi rise, PRC 285cc heads, a 246/254 cam, 4000 stall, 3.91 gears on 17s all around sporting race master 325/45/17 drs and I currently shift at 7400 rpm I am looking to go a bit more aggressive on the cam and valve train and spin it to 8000 rpm my question is would the hit downlow be to drastic that this car is not able to be driven daily anymore? Thank you so much in advance!

Undy

Personally I already think you're already nuts for shifting a stainless steel exhaust valved, PRC285, LS7 @ 7400 rpms. I guess you're just looking for a death wish for an already over-pushed engine. JMO...

nightmare2012

Oh I'm sorry I should've specified I'm going with link bar lifters titanium valves btr specified springs shaft mount rocker arms.

427ZM

Your avg. HP will drop, but I don't think it'd hurt too bad with your gears and the cubes of the LS7. Spinning to 8k though reliably is going to require high end lightweight valves (TiMO valves), link bar lifters (either Morel or Johnson), big high end pushrods (1.1 wall), polished and tumbled PAC springs, and probably a few other things I'm missing. And after all this, I'd still expect a fair amount of maintenance for the Valvetrain. Like, replacing springs every 5-7k, if not earlier.

Undy

Then I'd go with a solid roller, probably something around 275/285 with 0.730 to 0.760 lift. Street-ability will definitely suffer though. You can spin it to 8 grand but does it make power at that RPM though?

nightmare2012

Don't sound to bad I had already tooken into account all the valve train parts. Are the 3/8 pushrods the same as the 1.1 wall? So in daily driving will it be unreliable?

nightmare2012

I was going to experiment with VVT and rhino79 was going to custom spec me a cam that will make power passed 7600 RPM and maybe hit that 7800-8000 peak power. I won't risk reliability for a few rpms though

427ZM

No. http://www.tickperformance.com/pushrods-3/

And no, it won't be LS7 stock reliable. Typically, more aggressive you go, the less reliable it becomes. Our cams are compressing the springs and hanging open the valves as high as the cam lift is EVERY single time the crank turns. When you lengthen out the duration longer, then it's hanging the valve and compressing the spring as long as the duration states. Accompany this w/ cam lobe profiles and you get your valvetrain strain.

nightmare2012

Oh OK I'm guessing since I already spin up to 7400 rpm and it hasn't caused any problems for me yet I don't think the extra 200-400rpm will cause a lot of problems for me thanks for all the advice and pointers guys any other parts I may be missing don't doubt in letting me know and help me prevent from blowing up on the road Lol.

Michael_D

Have the rod little end worked and run better bolts, and move to a forged piston.

Turbo2L

I'd suggest rod bolts before you window the block with a rod cap.

nightmare2012

I have a completely forged bottom end with all the bells and whistles at a 11.45:1 SCR and maybe going to mill a bit more to maybe a 12.0:1

Turbo2L

I see. That's a little different from the HCI car you described in the first post. For the money you're spending to turn 8000RPM you could come out ahead by making more power under the curve for less money and risk.

nightmare2012

Hmmmm I like how that sounds could you please ellaborate?

Unreal

Spec a cam/intake/heads that makes power from 4-7, no reason to try to spin 7k+. As for another 200-400 can hurt, you realize it is expontial stress on rods with RPM. So 200-400RPM is a HUGE difference in stress on the motor. Hell, I wouldn't even try to spin any LS7 4" stroke to 7400 even with fancy stuff. There is just no point.

Twistedpixels

I am always thinking I have seen every type of crazy post with people trying to do things with these motors that are just plain nuts but I keep getting surprised.lol

nightmare2012

Lol yup we are pretty nuts! thanks for all of your insight and advice guys after talking to my builder/tuner he has set a plan for me to follow and I'll be able to spin up to 7600rpm maybe even 8000rpm to maximize my setup lower down how many shifts I have down the strip and get me into a mid 10 second pass n/a in a full weight(4000lbs) camaro

blacktavert

What is your RWHP with current setup?
With that setup on a stalled auto and drag radials, I am suprised you are not running mid tens already

nightmare2012

Haven't been on the dyno yet gears are bought not installed yet tuning hasn't been dialed in just yet since I've been having traction issues and I'm email tuning. My holley hi rise has a mismatched cam to it so thats killing my power as well I'm going with 17 inch weld RTS s77b and 325/45/17 race masters in the near future maybe even go full slick. My best time so far is a 11.0@126 with a 1.9 60'

63Corvette

If you plot RPM and engine life on graph paper, plotting the rpm on the X axis with up for more rpm and engine life on the Y axis with right for more engine life you will find that for rpm about 7000, the engine life is almost straight down, with life at 8000rpm measured in seconds, not minutes. If you also add "cost" as a function on the X axis, you will find that after 7000rpm, the cost goes almost straight up. Check out the cost of a NASCAR engine against the cost of an F1 engine. Your choice