How high can you safely rev an '04 4.8L?
#11
Destroyer of Transmissions
iTrader: (28)
I have a built tranny coming. Hopefully I will be able to shift as you say, I just e-mailed my builder and asked. What I was really wanting was for mine to be able to shift into overdrive at WOT. How can I make that happen? Right now, with the stock tranny, I have to get off the gas to get into overdrive, or maybe I just haven't left my foot in it long enough to see.....
#13
TECH Fanatic
iTrader: (1)
Originally Posted by hirdlej
Are these motors really that tough? I was thinking with the goofy oil pumping system we have with that long *** pickup tube and the concentric oil pump on the crank that these are weaker than the old style chevy smallblocks (i'm used to that old technology) Or am I wrong? Not trying to dog on these motors, I own one myself I'm just wondering how tough these things are compared to the smallblocks of yesteryear that I am so familiar with.....
Thanks already for the great input.
Joe
Thanks already for the great input.
Joe
#17
TECH Veteran
Originally Posted by Tiburon
Tell that to Randy.....
LOL, i don't think he's concerned about safely. if his lets go he'll just go bigger most likely. i wouldn't be nervous turning one 7200 or so if it were my own, but to say that some else's can go that high is a touchy area. the guys with the 5.7's and T-REX cam's are turning their bigger cube motors higher without much problem. after 6700 i'd personally say it's a let'r fling issue and don't cry if it breaks.
#18
TECH Senior Member
iTrader: (26)
The 4.8's have a lot shorter stroke and longer rod then the 5.3-6.0. I believe its a 3.26 stroke, which makes for a high rev potential motor. Plus it has the 6 bolt mains like the rest of the gen3 motor's. Like the other members here have said I think you have more of a limiting factor in the valve train then the bottom end.
#19
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Join Date: Jan 2003
Location: Fresno/Chico
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The 4.8 has a ridiculously short stroke (for being a V8). Stock the valve springs are the limiting factor. Upgrade those and you can REV the lill' 4.8 high. Being that its still a push rod motor you can put a 'Rev Kit' on it (a rev kit is a second set of valve spring on the lifter valley) though I dont know of anyone making one for the gen3's yet. I dont see why a mildly upgraded on cant rev to the 8-9K range (No joke).
Stock I would keep it in the mid 6K range with out better springs.
Stock I would keep it in the mid 6K range with out better springs.