How much power can a stock 4.6 bottom end handle?

[iBoost5o]

I'm just curious. I heard anything over 9psi was dangerous. That makes about 380-390hp at the wheels. If you add the 15%-20% parasitic loss then anything over around 430-450hp will break these things? Are the pistons/rods/crank any good in these motors?

 

[chimchim]

Well they're not forged and we've all seen those numbers you got there, but for how long? Just recently there were some folks on here talking about their 4.6 bottom ends breaking after running the 9# KB for a while. If you're going to add a power adder, spend the extra dough now and build the bottom with it. Spend 6K now and built it right with the supercharger instead of spending 3-4K on the supercharger, then spending another 3-4K and a bunch of heartache to fix it later.

 

[2000 blown conv]

I'm just curious. I heard anything over 9psi was dangerous. That makes about 380-390hp at the wheels. If you add the 15%-20% parasitic loss then anything over around 430-450hp will break these things? Are the pistons/rods/crank any good in these motors?

Depends on the tune...you could break it running 350 RWHP or you could run 400 RWHP for quite awhile with no problems..I'm pushing the envelope with what I'm running but,,I am also planning on putting a new longblock in this winter..

 

[COramprat]

If all goes well around 400-425. But that would be the extreme edge. I'm not even close....

 

[One Wicked SVT]

400rwhp is max life expectency.


then BOOM!!!!!!

 

[aggiedj02]

yeah anything over 400rwhp and your bottom end is living to die