What makes these engines so gutless?

[hce]

Gas engines are not as rpm limited. Modern gas engine peak horsepower is higher then a idi governed rpm. This lets them get more air through the engine allowing them to burn more fuel. More air more fuel more HP. Yes torque is great for towing, but spin a engine and use the next lower gear and you will have more torque to the wheels. Another limiting factor is the stanadyne pump cannot fill fast enough past 1400 and limits fuel to the cylinders limiting upper hp. If you ever drove a large industrial gas engine that operated in the same rpm as a diesel you would know what gutless is.

 

[BDCarrillo]

Apples to oranges. You have to look at what the design criteria was (which was covered here already for the IDI) I had a 2.4 liter gasser that put down more power than our IDI's... but that thing wouldn't last 250,000 miles and the cylinder head costs more than one of our trucks.

Cheap, fast, durable. Pick two. The IDI really nails cheap and durable

 

[chris142]

I used to drive 366 and 427 tall deck engines in a U-Haul type of truck. As well as a 392 in my international.all of these would out run my idi any day.especially the 392! That would go up cajon pass in 4th grossing 13k @60 mph at only 2500 rpm.that one did suck fuel though. But with gas being cheaper the cost to run would be nearly the same

 

[IDIoit]

before my rebuild, i had a 7.3 with a ZF5, 3.55's 105 cc IP and mister injectors.
supported with a 093 ATS.
my truck was far from gutless, and i could hang with a stock 01 7.3 powerstroke.

i had to be carefull on take offs that i didnt rattle my truck with wheel hop.
something im anxious to enjoy getting rid of that demon.

 

[OLDBULL8]

Damn Diesel's should have spark plugs. Do you know how much HP it takes to shove that piston up to make 500 air PSI so the fuel will explode?
All kidding aside, it's easier to fine tune a gas engine than it is a diesel, not computer controlled either one.

You say you have the timing set at 8.5* BTDC, how do you know that's the correct timing for the most efficient running?
Did you Dyno it at various degrees and that's where you got the most HP and torque.

You say a gasser will out pull and run faster than a diesel. Why then do you have a gutless diesel?

U-haul went from gas to diesel because they where more efficient, until stupid people couldn't read "DIESEL FUEL ONLY".

Diesel fuel used to be really cheap, fact is at one time they didn't know what to do with all of it. Until the Steamships converted to diesel, railroad engines went from coal to diesel, large trucks went from gas to diesel, Electric generation plants went from coal to fuel oil (Same as diesel fuel), supply and demand, then the EPA stuck there nose in it, get rid of the Sulfur, takes a whole different processing.

I my diesels.

 

[chris142]

I was not looking for a diesel.my truck was in the best condition I found in my area.just so happened to be a diesel

 

[Greg5OH]

turbo it though, seriously.
Like I said, NA diesels are-by design, quite anemic. its all about volumetric efficiency. Only so much air you can move with low RPM and N/A port filling.
Turbo it, can aachieve way higher than 100% VE. Diesel rotating components and blocks are very stout to withstand the immense pressures created, they can take bost (head bolts are the weak point on our engines-stud it).
I have no complaints with my truck, I can get to 70 mph pretty quick on our short Michigan on ramps.
N/A...yes it did suck.

 

[david85]

1: RPM limit. As mentioned, high revving engines will make more horsepower if you wind them out in a low gear. This will negatively affect the longevity of the engine however.

2: No turbo. Take any modern diesel and remove the turbo - THEN you will see gutless.

3: I'm not 100% convinced V8 arrangement is a factor. Bore x stroke ratio, camshaft and valve arrangement are what give an engine its powerband characteristics. Modern engines are multi-valve for more high end horsepower, and many make use of variable valve timing to try spreading it out more. Inline 6 is better balanced and has more main bearings to potentially support more power/torque, but no OEM engines produce enough power to push those limits in stock form. As for what wins on the track? Well, usually the guy with the biggest budget wins.

What sold me on the IDI was the simplicity and low cost of replacement parts. You can rebuild an IDI for the cost of a fuel injection system on some of the new stuff. Its sometimes claimed that common rail injectors are designed to last the life of the engine...that doesn't seem to happen very often, so the "wear" item status of IDI injectors isn't such a big deal as we were led to believe.

 

[chris142]

Old bull.as far as timing I set it where folks here told me to.i read here once about a lower HP 6.9 and i bet I have that engine

 

[OLDBULL8]

Old bull.as far as timing I set it where folks here told me to.i read here once about a lower HP 6.9 and i bet I have that engine

Scrape the dirt off the pad next to the IP on the drivers side. If you have a 6.9 the serial number will start with 6.9 * U ******, if it a 7.3 it will start with 7.3 * U *****. A number after the 6.9 or 7.3 is the generation. 6.9 2 U *********** would be a second gen.

The 8.5* BTDC is the factory setting on a new engine, not necessarily where an old engine should be set at, it's only a starting point. The condition of the IP and Injectors are a big factor where the timing should be set at. Fer Sista.

 

[chris142]

It's a 6.9

 

[freebird01]

I've found my idi's run best at 9.5*

 

[FordGuy100]

Air and fuel are out limiting factors from the factory.