[B]How high can we SAFELY run the 4.6 2V NA with a stock bottom end? My Cams pull to 6200. I turned my Rev Limiter off at the track and ran 6800RPM at the trap. I'm thinking that's a wee bit HIGH.:bash:

 

which cams do you have? i think most cams quit making power around 5800(other than radical cams)

 

I wouldn't go over 6200rpm on the stock rods. they're just not up to it. You might get away with it a few times but it's just tempting fate. If your cams pull to 6200, then there's no sense in running it to 6800.

 

How do you know your cams pull to 6200 and how are you crossing the traps at 6800? What valve springs are you running? Also, what heads/ intake?

 

I cant believe your car didnt die at 6800 rpm. I wouldnt suggest you did that again, unless you want a forged block and new heads...

 

Wow, thats pretty high...Can't believe your engine took that.

 

wow! I agree with everyone on this one

 

highest safe rpm would be 6,500 with upgraded valve springs on stock bottom end. But i wouldnt bother its not worth the risk to me.

 

Also do you have gears, power adder or finished the traps in 3rd gear, if quarter mile track?

 

i've seen a 4.6 bone stock bottem end with cams also that ran it up to 7200 and a built and blown 4.6 up to 7800 but i'll only bring mine to 5800-6000 at the most... thats when they stop making power so there is really no sense in going that high unless you're just looking for a reason to build a motor

 

with stock cams and intake the 4.6 2V is usually going to start the downward slope just after 5200rpm for hp and right at about 4800-5000 on the tq curve. Adding hotter cams will stretch that out a bit but the heads need to be ported for more flow if you want to wind it up really really high. They just don't flow well enough to support super high RPM. That's why 4V's were created.