1994 Ford F250 7.3 Turbo Diesel

like seriously! i think powerstrokes are an addiction...i have to keep reminding myself that one hot money pit is MORE than enough for now! lol

 

Lets see...325k miles....replaced right front rotor, why not both...oil leak in pan gasket..why hasn't fixed this (maybe because rings are shot and it allows the blo by pressure release).... asking $2800....my offer 0 dollars.
Of course I don't really know anything about diesels so I am biased.

 

I dont need another toy either, even tho that block would be perfect for what i wanna do

 

if you know what you're doing and can fix stuff...or even just to play around with it, i'd jump on a 7.3 for under $3k. although i am learning to be better at bargaining

and 325k aint so bad for a diesel...i fully expect to get 500k+ out of mine if i take care of her; it's been done plenty of times before!

 

Yeah I don't know about diesels, so I'm thinking like it's a gasser
Always bargain though

 

and i've decided i will never ever own another gas truck...i was sold the first time i put my trailer behind her

...ok, well maybe more like when i fired her up for the first test drive...

 

So why is it diesels last so long ? I am interested now and want to know more

 

There built to last, hence why they way almost 300 to 500 lbs more than all gas motors.

 

So the combustion of diesel is more powerful and the block needs more reinforcement ? It's not like gas engines are disposable, although I do have a remanufactured in mine.

 

mwuahahaha! maybe i can convert you! lol...diesels are an addiction

 

Well if I quit smoking I could take that $$ and......so your going to let me test drive your truck ?........anyway Happy V day Katie

 

quitting would save you a few hundred a year i bet...we did the math for my grandmother a while back when we made her quit. ...although it ended up being threatening not to visit that did the trick lol

oh and there's another 7.3L obs in the virginian-pilot classifieds for $2k!

 

Some quick diesel trivia:

Diesels have no throttle plate, compression between 18:1 and 22:1, and almost always some (lots) turbo boost on top of that. 20-30 PSI. They're necessarily built much, much stronger. Huge rods, big bearings, etc., better metals and tighter tolerances. Instead of compressing an air/fuel mixture, only air is compressed- and with the very high cylinder pressures, it's hot enough to ignite fuel. Around TDC, diesel fuel is injected through a very, very fine injector, and the total burn time is slow and smooth. So the bottom end never gets "hammered", and the fuel injection duration limits the top speed. I believe most pickup truck diesels redline in the 2500-3500RPM range.

No worries about rod knock. If it's not burning oil (top-end is OK), starts when cold (compression good), and doesn't smoke too much (injection system OK), then it's mechanically sound.

Unless the motor has been in a dump truck or pulling huge trailers, a big turbo diesel has been loafing it's entire life. I'll bet lots of rusted, busted diesel trucks go to scrap with the cross-hatching still on the cylinder walls. At 325K, I'd be thinking about refreshing the rest of the driveline- ujoints, ball joints, pumpkin play, tranny fluid & filter- all the things you'd expect on any vehicle with 325K. The 5-speed manual is tough as nails and highly coveted.

 

Now we are getting some where. I have been viewing diesels in a negative light the sound of a diesel to me wsa based on gas engine criteria so they sounded to me like they were on the verge of coming apart, and I figured they were slow like a semi gearing up a hill. So the above information has been eye opening, and I especially like anything built to last in a heavy duty manner, now I want to learn about the latest diesel technology.

 

The clatter you hear is the injectors popping open at high pressure- old diesels are around 2,000PSI injection pressure. New "common rail" diesels are 11,000PSI or higher, with short, multi-squirt bursts, which is why a 6.0 PSD sounds like sleet on a truck roof, and a 6.9IDI sounds like a dryer full of billiard *****.

Typically diesels have all forged internals, and will rattle to wake the dead on a cold day before they've warmed up. It's not bad, it's just loud. My Mercedes sounds like it's full of marbles on a cold start at 10F, but after 5 minutes it just clacks along like an industrial sewing machine.

As for a semi lumbering up a hill, that's because big over-the-road motors are downrated- a turbocharged, all electronic 9L motor might be rated for 375HP. That's not much better than a 5.7L Hemi Dodge, and that truck's not going to go up that hill any faster than a Hemi Dodge would if they were both pulling a 30 ton trailer. But that 9L diesel will pull that trailer for millions of miles, up hills and down, and the Dodge Hemi won't. I'd be interested to see a Hemi vs. LSx vs Triton 5.4 in a 30-ton torture test.

The ill-reputed GM 350 diesels weren't particularly bad motors. Good power, and pretty efficient. The problem was GM didn't go all the way making it a diesel motor, and they weren't fault tolerant. GM used regular gas motor head bolts, which would stretch enough over 40K miles to let the head gasket go, and maybe warp the heads. Also, there were no water separators and diesel fuel in the 70's and 80's was very dirty, and the steam pressure in the chambers would REALLY overpower the head bolts, and you'd loose gaskets at 20K.

The upshot of that is, the GM 350DX diesel block was a super-beefy large-journal 350, with deep webbing, thick cylinder walls and superior castings. They make fantastic blocks for gasser race motors.

Current neat-o diesel tech: common rail direct injection and variable geometry turbochargers. Ford has a 4.5L V6 powerstroke used in commercial box trucks that would be awesome in an F150/F250, but it's not refined enough for passenger vehicle use (I rented a 4.5L Ford LCF when I moved). I think the 4.5L is two serial/sequential turbos (big feeding a small with a bypass). Small=fast response. Big=top-end power. Typically you choose one. Variable geometry did much to alleviate this, but it was always a complex compromise. 7.3L Powerstrokes are larger fixed-geometry. 6.0PSD was variable-geometry, and gave "off-idle" boost. They just got up and went. 4.5L was programmed to be very smooth and consistent and easy on cargo. It never felt quick, but my wife struggled to keep up in a V6 sedan, so it must have been doing something good. I rented a more traditional 5.2L GM/Isuzu box truck once, and that was the classic diesel punch off the line (great, great torque) that you get with non drive-by-wire, but fell flat until the big turbo kicked in. Not as easy to drive gently.

The "big 3" all have great diesels right now. Dodge Cummins, GM Duramax (really Isuzu) and Ford Navistar all make a stout, powerful engine, and it's a Coke/Pepsi Ford/Chevy holy war any time you try to compare them. The inline-6 Cummins ISB used by Dodge has historically been the choice for long distance light trucking (horse trailers, etc..), because it's just the little brother of the Cummins ISX that's used in semi trucks. There's a 3.9L 4-cylinder ISB motor that's used in box trucks all over the world. There's now a 6.7L ISB motor available for the Dodge trucks. The V8 GM/Ford motors have been kind of an anomaly until recently. In the diesel world, simpler is better, and if you need more power, build it bigger, with more turbo. But the autobuying American public things power=V8, not I6. All GM motors prior to the Duramax weren't as good as Ford/Dodge, because GM kept building their own. The early 6.2L GM motors are solid, but dog-slow and finicky. 6.5L turbo all-mechanical motors are what's used in the HMMWV. The Ford 6.9 is a very solid, simple motor. 7.3L motors had issues any time something new was introduced (turbo, direct injection).

Factoid: Direct vs. indirect injection: direct injection sprays the fuel right at the piston. Indirect sprays into a little pre-chamber that's connected to the main combustion chamber. The main benefit used to be easier starting and smoother burning with a slight efficiency drop, but modern injection technologies have eliminated the starting issues, and everything is direct-inject now. "Powerstroke" are the direct-inject (DI) 7.3L turbo motors.