What is the best of these three Diesels as far as. POWER and RELIABILITY.

 

cummins hands down. the 6.9 was a good engine but a bit down on power from the cummins. the 6.2 doesn't even compare to either of these. in the pre-psd era, the turbo'd, intercooled I-6 cummins had the advantage in power over the non-turbo V8 6.9. as far as reliability goes, they are about the same.

disclaimer: i do NOT like the cummins more than the psd. but this does not concern the psd.

 

the 6.2 was a joke i would go with the cummins although the 6.9 was a very good engine.

 

Just curious, does anyone know when each of the engines were available in thier respective vehicles?
I have a feeling the 6.9 was first offered in 84, but I am not sure..

 

I had an 83 F-250 with the then new 6.9. It was a regular cab, auto with 3.54 gears. I pulled a 5er with it and it did a fabulous job. I had only once pushed it beyond its capability and had 32,000 pounds of load and trailer behind it. It wouldn't pull it over 50 mph but I also wasn't going far with the load. It got great fuel mileage empty, 26-28 hiway at the speeds of those times. I had injector pump troubles with it though and Ford pretty much said it was my problem. I found an old boy that built me a pump and it lasted for as long as I kept up with the truck. I sold it to a friend and the truck all but fell apart on him at 30,000 miles. The bottom pulley came off of the crank and went out thru the radiator and A/C and ripped the alternator and fan off of the engine. Ford split the bill with him which I thought was pretty decent of Ford. The engine block cracked at 100,000 miles and he had it drilled and welded. I also had a bud with the Cummins. Mine would out pull his in a heartbeat and get about the same fuel mileage. This was before the torque wars of today and the diesel engines got great fuel mileage. The Cummins was probably the most reliable. The 1985 series of 6.9 was the most reliable for Ford. There was a head gasket issue and injector pump issues that they worked out for the 85 year model. After their modifications to the head gaskets, power suffered as they reduced the compression ratio a bunch. My 83 was running 24:1 compression and it was reduced somewhere around 18:1. My 6.9 at the time would stay with a 454 SS Chevy from light to light. It was quick and most didn't believe a diesel would move like that. The 6.0 seems to be close to being as quick. I always thought the 7.3 was a slug as compared to the 6.9, reliable yes, but slow. Great memories of that truck.
As others have said the Chevy diesel was a joke. Reliabilty and that engine can't be said in the same sentence. The Cummins was the most reliable as far as the engine goes. Dodge has had and continues to have problems with the lift pump (fuel pump) but that is a Dodge problem, not a Cummins problem. The Cummins has had some injector problems along the way but that has been addressed and corrected. The easiest to service was the Cummins by far. Everything you need to get to is at your finger tips. Too bad Ford doesn't try that with their present day diesel engine.

 

How much power can you get out of these engines and still have reliability

 

Flash, are you sure the 6.0L of today was slower then the 6.9 in '83? I'm sorry but I'm having a hard time believing that. Not to mention the 7.3 is in fact faster then the 6.9. Wasnt the compression 22:1?

 

To answer the question, (edited - BigF350, language) the 6.9 and Cummins were very good reliable motors.

 

NickFordMan, maybe it's not a fair comparison but the 04, 6.0 we have at work is a Crewcab and a 4x4 which I'm sure effects the performance overall but the 6.9 I had was a screamer. Like I said, afterwards they lowered the compression ratio by quite a bit. If you have experience with the 6.9, it will make a difference as to the year model. The early ones were were strong as new rope.

I just remebered that I have time slips on that thing somewhere around here. I run it thru the lights one nite when it was free to race. Don't go run to the bank with this but as I remember, it was in the mid 14's. IF I can find them, I'll post the slips or PM you with them.

 

If you can find those slips then yes, I'm interested!

 

Nick, you are an incredibly diplomatic human being.

Those things had around 180 HP and 365(?) torque.

With all due respect, mid 14's..............in the 1/8 mile maybe.

 

I was trying to be positive, lol, I know its basically PHYSICALLY IMPOSSIBLE (without insane gear reduction) to get those kinds of times. Thats why I asked for the slips for his proof. (No offense Flash, I wasnt expecting very much)

 

I had an 84 with a 6.9 and it was reliable, but very very slow. It was turboed also. My new 6.0 blows that 6.9 away.

 

This is one of those things I do not understand....why the 6.9 gets beat so bad by the 6.0s

 

Its not really fare to compare a early cummins(89-93) to a 6.9(83-87) the 6.9 was gone before the cummins even came out.
plus Motor wise yeah the cummins is superior. but Everything else on that dodge chassis is junk. I'd buy the ford any day for that reason. If you want a cummins stick it in a ford.
as far as the 6.9 to 6.0 comparason I know I seen some pictures of a twin turbo IDI That would proably do 14s.
I don't know about that I test drove a 6.0 in 03 and my 92 7.3 IDI wasn't far off from it. the big difference between the trucks was it was an automatic and mine was a stick I had 4.10s it had 3.73s..... oh yeah it had a turbo I didn't.