Slow revving 460
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From: Spencer Ohio
Slow revving 460
I just picked up a 1996 F-250 4x4 with the 460 and 5 speed manual trans. It has a 100k on the odometer, so I did an all motor craft plugs, wires, car, rotor, and fuel filter tune up. I installed a K&N intake and straite piped her with the 3" flow through filter for exhaust. My question is the truck runs great has lots of power but revs very slow from 3-4k. I can't get it to rev past 4 k and i know it isn't hitting vev limiter? Any ideas would be great.
Brandon
Brandon
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From: So Cal
Does it rev better in a lower gear? What rear gear does it have?
The mid 90s 460s were not RPM engines. I think they redline at maybe 5,000 RPM and all they do is make a lot of thrashing around noises above 4,000RPM, but not a lot more power. I think my 94 with 4.10 gears in an auto gets to maybe 4,500 RPM but it is more comfortable and less noisy below 4,000.
If everything is normal and your engine is still slow reving, maybe your fuel filter is plugged? Mine ran OK and at about 70,000 miles or so I didn't notice anything. But towards the end of those miles it seemed like it didn't have any pep in it when towing the trailer. Also whenever I switched tanks it would stumble badly. I changed the fuel filter and what a difference, wow.
Maybe your filter is due for a change. I think they are to be changed every 30,000 miles or so. Many of us forget about this small maintenance item until it causes problems and most of the time the problem sneaks up so slowly it takes awhile to notice.
Good Luck,
Jim Henderson
The mid 90s 460s were not RPM engines. I think they redline at maybe 5,000 RPM and all they do is make a lot of thrashing around noises above 4,000RPM, but not a lot more power. I think my 94 with 4.10 gears in an auto gets to maybe 4,500 RPM but it is more comfortable and less noisy below 4,000.
If everything is normal and your engine is still slow reving, maybe your fuel filter is plugged? Mine ran OK and at about 70,000 miles or so I didn't notice anything. But towards the end of those miles it seemed like it didn't have any pep in it when towing the trailer. Also whenever I switched tanks it would stumble badly. I changed the fuel filter and what a difference, wow.
Maybe your filter is due for a change. I think they are to be changed every 30,000 miles or so. Many of us forget about this small maintenance item until it causes problems and most of the time the problem sneaks up so slowly it takes awhile to notice.
Good Luck,
Jim Henderson
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From: Spencer Ohio
You would think if the timing chain streched the truck would run rough? It runs great has lots of power just doesn't like to be revved. This is my first big block motor and it may not rev that high. What is the rev limit on this motor?
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From: Carmichael, ca
A stock 460 is not going to make power past 4,000. Even 'built' 460's max out around 6,000 rpm, there is a lot of rotating weight in them. If you are looking for more power and rpm's you have to rebuild it with a proper combination of pistons, heads, cam & valve springs, intake, carb, headers & exhaust.
It's very easy to make 500+ hp with these engines with a stroker kit, etc.
It's very easy to make 500+ hp with these engines with a stroker kit, etc.
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From: Central British Columbia
03,
Double check and triple check that #7 & #8 plug wires are in the correct positions and are nowhere near each other(Min 1" space between them). 7 & 8 can be mixed up and the eng will still idle smooth and pull OK in the bottom end but will not have any top end at all.
Kurt
Double check and triple check that #7 & #8 plug wires are in the correct positions and are nowhere near each other(Min 1" space between them). 7 & 8 can be mixed up and the eng will still idle smooth and pull OK in the bottom end but will not have any top end at all.
Kurt
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From: Spencer Ohio
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i have the 460 in my 85 ford dd/pull truck and i can get 6 grand out of her with no problems but go over that and the valves state floting realy bad
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From: Spencer Ohio
The spark plug wires are correct, yet the motor will not rev past 4k? Has all the power in the world up to that. I can't figure it out, I checked my timing and it is at 10deg is that normal? I would think 12-14 would be better.
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From: Hesperia, CA
Originally Posted by 03 Power Smoke
The spark plug wires are correct, yet the motor will not rev past 4k? Has all the power in the world up to that. I can't figure it out, I checked my timing and it is at 10deg is that normal? I would think 12-14 would be better.
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From: Central British Columbia
03,
With the eng shut off check how much play in crank degrees there is on your timing chain using your timing pointer. Eng will turn freely back and forth between chain slop. Should be not more than 5 degrees. If the chain has stretched then jumped so that the cam is now advanced that would kill top end. Your eng should pull easily to 5000 RPM. Also check total timing to see what is going on as well. Ideally 36 deg total is best for most 460's. Does it have a stock disy? What is the rest of the history on the truck? Has the previous owner installed an R.V. cam and advanced it to far? Great for towing but would kill all top end.
Kurt
With the eng shut off check how much play in crank degrees there is on your timing chain using your timing pointer. Eng will turn freely back and forth between chain slop. Should be not more than 5 degrees. If the chain has stretched then jumped so that the cam is now advanced that would kill top end. Your eng should pull easily to 5000 RPM. Also check total timing to see what is going on as well. Ideally 36 deg total is best for most 460's. Does it have a stock disy? What is the rest of the history on the truck? Has the previous owner installed an R.V. cam and advanced it to far? Great for towing but would kill all top end.
Kurt
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