It's a '97 F250 crew cab short bed 4WD with 460/E40D, 4.10 gears, slightly larger than stock size tires, completely stock other than a universal AEM air filter (somebody previously tossed the original air box). Rebuilt engine had 20k miles on it, it had a bad MAF and was running lean so #5 piston burned and had low compression. This is the point where I bought the truck cheap, pulled the engine, put a new piston in, honed and re-ringed all eight with moly rings and put it back together (with a good MAF). Runs smooth, sounds great and it's got about 300 miles on it since my work.
So today I hook the trailer on (20' enclosed, about 7k or 8k lbs fully loaded) and the truck can barely make 55 mph in 3rd gear climbing the hill into Tooele (not a very steep hill). To me, it feels like a good running 351 power wise, not a 460. I hook the scanner up, no codes, and O2 sensors are pegging out at around .9 volts at full throttle (indicating richer than stoich). Base ignition timing is at 12 degrees, no detonation heard. All ignition components are new. Fuel pressure is normal, even under load. Exhaust is clean, and no abnormal blowby.
In contrast, my previous pickup was a Chevy K3500 with 6.5 diesel (rated lower in both horsepower and torque than the 460) would easily outrun my current F250 with the same trailer.
Is this all I can expect out of it or is something wrong?
Thanks

 

If you can climb a 12* grade with 6500lbs of truck and 8,000 of enclosed trailer @55mph you should be HAPPY

But I find that hard to believe the GUTLESS 6.5 would out pull your 7.5. I would be looking at a clogged cat

 

I agree plugged cat. If that doesn't do it then do a fuel system check, check the pressure and the regulator, install new fuel filter, and try again. I was thinking the same as brad though, It doesn't sound that underpowered to me.

 

It's probably about a 1% or 2% grade, not very steep. I'll try the fuel filter tomorrow since I have one on the shelf and maybe take a peek at the cat. All I know is that if this is all it's got, then I'm selling for a powerstroke.

 

Do you mean wide open it hardly makes 55 if so something is really wrong

 

6% grades are about the max on most highways. Sometimes you run into 7% on some of the older roads but they are as a rule pretty windy.
Personally I think you should set your rings in better before pulling a trailer. I would put at least 1000-1500 miles before hooking up a trailer. If your used chrome rings you need to vary speeds for the first 500 miles. You chance not setting them in which will show up down the road.
Then I tow regularly & I see what I think is just stupid stuff. Guy pulled out before me, I'm in my car. I;m running 70 mph on the freeway & this trailer & truck is pulling away. About 10 miles down the road I see him pulled over. Two blown tires & half the undercarriage of the trailer tore up.
55-65 mph is all I tow any of my trailers. Tires & repairs are too costly these days to get somewhere 5 minutes earlier.
I tow with a V-10 Dodge that will pull my 10,000# trailer 100 mph if I want to be crazy.
Craig

 

The Dodge V10 is also rated around 290-310HP if I remember correctly. That's significantly more than the late model EFI 460s.

 

That's right, that's all she's got.

The previous owner told me he had the exhaust apart and saw that the cat wasn't plugged but I got thinking that with the Y pipe the way it is he would have only seen the back of the cat which probably would look fine. I'm betting (or hoping) that the cat is partially plugged. We'll find out tomorrow.

 

I seldom tow faster than 65. The heavier the trailer is loaded, the slower I go.

As for the rings, I simply don't have the option to wait 1000+ moles before towing. Instead I have just been taking it extra easy. Today was the first full throttle run with some weight, and it was brief at that.

 

What a disappointment!

I pulled the cat out entirely, it's not clogged at all. I pulled the old fuel filter out and a bunch of muddy gas came out, and I thought just maybe that is it. I put the new one in and nothing's changed, it's still a dog.

My buddy is offering me his 4WD F250 chipped '01 Powerstroke with BTS trans for $5000, all I have to do is finish putting the rebuilt engine back in it. This might be the way to go?

 

My '96 would pull 14K around without too much effort.


I bumped the timing to 12*, cut the air intake restriction and a turbo muffler.

I went from that, to a '99 V10/5spd/4.30 CC DRW and it did about the same powerwise, only better fuel economy. My '00 PSD CC DRW/6spd/4.10 did the same, but even better fuel economy. Both stock trucks, no chips.

I have a big hill that is my "test" for all my vehicles. They all got to the top at about the same MPH.

 

What's the compression like on the 460?

 

All cylinders are close enough to each other, in the 130s according to my gauge.

 

130 seems a bit on the low side. I'd expect more like 150, especially with the stock very mild cam. Might want to do a leak down test, maybe your rings may have not seated properly.

I just noticed you said 55 MPH in 3rd. 55 MPH in 3rd with 4.10:1 gears and ~33" tires is 2300 RPM. Let the truck rev man. While it has a lot of torque for a gasoline engine, it's still not a diesel. Your truck should be able to hold 2nd all the way to 65 MPH, 55 would only be 3500 RPM.

 

What RPM do you recommend for towing with a 460 ?