Do most of the 5.0's really fall flat on their face at 4000 RPM?
Well.. saying it goes "flat on it's face" may be a bit harsh. The '94+ truck motor(which has the same cam as the Explorer motor) will rev to 5k no problem. There's a bit of a plateau between 4000 and 5000 where there's only about a 10hp variance so it may be hard to tell. Tachometers can be off a couple hundred rpm too so that may also factor in. But regardless the curve turns downhill after 4500 and starts dropping fast.. down ~25hp by 5500, so the motor is just making noise and not accelerating any more. Drive an 5.0 mustang and you'll immediately see a difference in the way it pulls up top, and that's all due to 10deg more duration on the intake side of the cam, that's it.
P.S. The pre '94 truck motors are much worse too, especially the pre 92 flat tappet motors, they were all done at 3500rpm just smothered beyond belief with that old cam.
__________________
Paul O
1990 F150 4x4 XLT X-Cab 5.0, 3.55LS, Comp XE264HR-14, Flowtech LT's to 3" single, FRPP Mass Air Conversion, TweecerRT with BE, Innovate LC-1 wideband O2
Well, I got a pre-92 flat tappet cam. And, as you may remember, I posted vids of it pulling hard to 5k RPM. I'm hoping it has a cam in it. Oh well, I'll quit hijacking. You just really have got me thinking since I posted my vids a while back. My truck doesn't 'kick in' until 3000RPM. Then the sound changes and it just starts screaming (in a good way).
__________________ 1986 F-150 5.0 EFI XLT Lariat 4x4 NP435/NP208/9" 3.50
"Custom Exhaust" and leaf spring overloads
31x10.50 15" Nothing special, but it's a damn good truck.
Well, I got a pre-92 flat tappet cam. And, as you may remember, I posted vids of it pulling hard to 5k RPM.
Yeah we talked about that before and there is no way that is a stock 5.0 truck cam.
__________________
Paul O
1990 F150 4x4 XLT X-Cab 5.0, 3.55LS, Comp XE264HR-14, Flowtech LT's to 3" single, FRPP Mass Air Conversion, TweecerRT with BE, Innovate LC-1 wideband O2
Ever seen any 5.0 trucks dynoed before? There's a dyno in Bristol, and I live about 40 minutes from there. That'd be one easy way to see what's going on. I guess if I put down over 145RWHP, I'm doing ok, lol. Where at in the powerband would tell the real story, though.
__________________ 1986 F-150 5.0 EFI XLT Lariat 4x4 NP435/NP208/9" 3.50
"Custom Exhaust" and leaf spring overloads
31x10.50 15" Nothing special, but it's a damn good truck.
1990 F150 4x4 XLT X-Cab 5.0, 3.55LS, Comp XE264HR-14, Flowtech LT's to 3" single, FRPP Mass Air Conversion, TweecerRT with BE, Innovate LC-1 wideband O2
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