if ya dont like your idi you can donate it to me,i dont mind pulling hills slowly,it aggrevates people and makes me laugh,i do it unloaded sometimes just to bug people that are in such a hurry.the thing about these trucks is they WILL get there they wont be the first to get there but will be the last to break down.they are tough simple work horses.if you want to get a 6.7 to pull a hill and pick up speed with 10k lbs thats cool with me,ill tow you to the closest shop instead of passing ya.lol really though if you want to keep up with a 1st gen psd that isnt an issue ,dave has a 1st gen psd and his ole 6.9 idi will eat it up

 

Everyone forgets.

6.9 IDI generation 1
7.3 IDI generation 2
7.3 turbo IDI generation 3
7.3 Power Stroke OBS (94 to 97) generation 4
7.3 Power Stroke NBS (99 to 2003) generation 5
6.0 Power Stroke generation 6
6.4 Power Stroke generation 7
6.7 Power Stroke generation 8


What seems very funny to me, back in 1974 I was driving tractor trailer cross country with a HP number close to what the 7.3 IDI turbo puts out.
Yes that 220 Cummins did have a bit more torque, but 220 HP and 73,280 pounds was my normal gross weight.
And I drove over 100,000 miles a year.
45 is slow up a hill?
You don't know what slow is.

Some of the local mountain roads are around 10 to 11 percent grade.
I could walk as fast as those trucks went up therm.

 

To me the ol IDI's are old war relics. They aren't as young, agile, adaptable, or powerful as the new army, BUT the old soldiers know war.

Heck last week I hauled 4 tons for pea gravel in my bed for a buddy of mine. Now sure a new 6.7 could prolly haul the same load 4 times as fast, but who would let a crackhead looking loader operator dump 4 tons of gravel in a 50K truck, but heck for my 1750 buck F350, heck if he hurts it all well.




Plus my big reason I still have my IDI is I run 50/50 diesel and WMO everywhere I go, let me see a 6.7 or a 6.4 do that HA

 

Interesting read guys, I do run porpane on my truck and I have for 8 years.


Here are the actual dyno numbers: 7.3IDI Banks box style turbo:

First pull, no LPG
HP 183.15 Torque 325.45

2nd and 3rd pull with LPG

HP 205.35 Torque 362.64
HP 205.51 Torque 361.55

So 22.96 increase in HP
and 37.19 increase in Torque.

I have had this LPG setup on 2 different trucks with 3 different motor combos.

First
1987 F250 6.9 NA
Second
Big Ed with 7.3 Banks Turbo Diesel
3rd
Big Ed with the Cummins

I have only dynoed the 7.3 Banks Turbo so far, but will dyno the Cummins when I have the opportunity.

 

You have a turbo, which if I remember right the original poster did not.

Till you look at the cost of the install, the cost of propane and the time to go fill the tank, rather expensive for 22 HP.

I am not going to say it don't make any extra power, but I will say not worth the headache.

And all it will take is one time with a bit to much 'pane and the head gaskets are short for this world.

 

i know each state is different but in missouri i can license up to 24,000 without commercial plates and insurance.... over 24k is commercial..... true with the weight of the truck it was well over the 24k but it moved it and in the cuontry roads between where we are and where we were going DOT is none existant and so is traffic really..... love the country... trailer brakes play a big factor in the stopping.... i wouldn't pull anything on my big trailer if it was'nt for the trailer brakes

 

The original poster is going to run twin turbos.

Yes you can spend money on a Bullydog ($600.00) system but my system is a home built system that cost me under $100.00 to build. I use a 20LB propane tank that I usually only have to fill a couple times a year depending on how many miles I put on it. Plus it does add to your MPG enough, or a little more to cover any cost for the LPG.

I also have it set pretty conservatively, so I am not worried about the head gaskets. I can get more power out of it if I wanted to, and could also get more power out of a Bullydog system that has a setup that will give more propane at higher boost, but mine is an on or off system.

So for me to gain 23HP and 37Tq, about a 12% gain in power at the flip of a switch,...Yes,.....it is defiantly worth it.

Now I have to dyno the truck with the Cummins and see where I am at,...

 

I don't know about there, but here the DOT would love to catch you running a 20 pound cylinder hooked up while driving.

Same thing as driving a service rig with the regulators on the oxy acetylene bottles.

Unless you can find a used DOT approved mounted tank, a new one is about 400 dollars.

DOT here has stepped up patrols and hastle everyone for everything here lately.

If I did not have commercial plates and a DOT number on my truck, they might not watch so close.
But if I didn't have all that, then they would be busting me for overweight.

Can't win for loosing anymore it seems.

 

DOT here is cracking down too, and are focusing on 3/4 and one ton trucks, as so many are used by roofers, landscapers, contractors, etc and aren't always looked after the best. Give it time and other areas will follow suit.

 

That twin turbo deal, not something I can see ever happening.

Just to hard to get the engine to a place it could stand that much boost and still be avble to start it when the temp was below 90 degrees with the block heater plugged in.

Once you go over 20 to 22 PSI boost, to many other things need mods.

Intake manifold/valley pan will be the first thing that blows.

Next the exhaust manifolds and those nice flare exhaust joints start leaking and the boost starts dropping.

Mill the pistons much more than .040, forget zero weather starts unless it is plugged in and the glow plug system is in top notch shape.

Even with head studs and pistons milled .040, about the mid 30's for boost and the head gaskets are at issue again, so now you are looking at O ringed heads, lots more money.

Don't forget the intercooler.

Probably ought to think about a block girdle as well when you go over 25 PSI or so.


If you are going to build a novelty truck, driven every once in a while on special occasions, with enough money you could build something like that with gobbs of power.

But if you are thinking an everyday driver, not something I would want to depend on to start and run every day.

Not even somthing I would want to bet money on making it back home when I did take it out.

I figure 300 is reasonable and rather reliable when you get the kinks worked out.

By the time you hit 350, the reliability is going to be an issue.
It is going to be tempermental about starting.
Stupid parts you don't normally think about are going to start causing major issues, always at the exact wrong time.

Go higher than that, it is not going to be an issue of if it will fail, because it will.
The important issue will be how long will it stay together.
Hopefully long enough to make it back home.


My first race with a Cummins after I built and broke in my engine, blew the valley pan when boost hit 22 PSI.
Boost pressure right into the radiator, blew the coolant out.

25 PSI, there goes the exhaust manifold gaskets.

Engine was fine, just the stupid parts you don't think about that you are also stressing.

I have even blown the threads out of the intake that hold the ATS turbo pedistal on the back of the intake.
That took out a couple of the intake system O rings.

 

1200 Hp Idi - MyTractorForum.com - The Friendliest Tractor Forum and Best Place for Tractor Information theres one for yall to drool over i wish it was still round to smoke out all these new diesels they cant touch 9sec with stock internals and here is what i figure that block was not solid filled if you built one today and had it filled it would not flex or blow freeze plugs and with modern tecnology and machines and water meth today it may be possible for 1500hp with a ton of $ just a thought if i win or make enough one day i will have to try to set the new bench mark for the old engine to stay ahead of the new chipped twin turbo trucks makin 1200 like its easy

 

I considered a propane system. I do not claim to know all the ins and outs, but I am a fast learner. My sticking point is the tank and filling it. A 20lb tank hook up would be a BIG fine. An RV tank is big and hard to hide. But most of all, how are you going to explain to the DOT officer that you are not paying road tax on fuel that is most definitely being used on the road? It's not like I have a stove or a refrigerator on board to point at.

In my neck of the woods, the DOT guys like to stop farm truck and stick the tanks checking for Tractor Diesel. While they are at it, they look for other ticketable items. A connected propane tank would be quite a find for them.

On another note, I read about some dude that was running highly compressed hydrogen injection. He made wonderful claims of power and economy. He also talked of "tossing" the tank in the back of the Excursion and connecting the regulator. Toss? Oh my! Someone has never been to a safety meeting! Hopefully he is still alive.

 

Not really the responses that I expected,

Its pretty frustrating,..Someone asks a question on propane so I post up on my experiences with using LPG for 8 years, on 3 different engines, with dyno results and these are the responses that I get,...?


,.....Paying ROAD TAX,...? Really,... Am I going to get busted for not paying road tax on the Diesel Fuel Additive that I dump in the tank? Cause I use more of that than the propane,.... What about NOS?

The 20 LB tank is inside my tool box in the bed of the truck, and is bolted in with a DOT approved RV hold down. I am not worried about the safety of the tank, installation, or getting busted by the DOT on it. I spent a ton of money and time building this truck over the last 8 years and I damn sure am not going to risk it, and the family If I thought anything was unsafe I would not use it.

So I hope that some of my time and information helped some on this board to shed some light on how LPG works,..

I agree,......

 

You have to understand where I am with my information.

First my truck is a business vehicle.

As such, I track every expense down to the penny per mile driven.

One of the big sellers for the propane systems is a mileage increase, with a power increase.

So I built a propane system, experimential.

I first ran it on a NA motor, no real power increase.
Also checking the MPG numbers, yes they were higher.
But when I plugged the cost of the propane and cost of the diesel together then ran a total cost per mile check against the cost per mile with just diesel, they were almost identical right down to the penny.

So the system went on the shelf in the garage.

When I built my IDI with a turbo, I thought I would give it a try again.
So back on the truck again.

Yes I did make a bit of extra power since I now had plenty of air in the cylinders.
Ok this is good.

So I start looking for a frame mounted DOT approved tank.
Here in town the local propane dealer could get me a new Manchester tank, 30 pound if I remember right, for 650 dollars.
Remote fill was extra, lines were also extra.

So once again I looked at the MPG numbers and cost per mile numbers trying to justify almost a grand in a road legal system.

Sadly now they were worse on a per mile basis.

Not what many people have reported, in fact my findings were the opposite of everything I have read.

Maybe I did not find the sweet spot with the propane adjustments.
Maybe I am running to much boost.
Could be the terrain here.
Might be the way I drive.
Could be the way I have my engine set up.

So my findings go like this.

I will agree you can make a few more HP on a turbo motor.
There is a MPG increase, but the cost per mile is either even or slightly higher, but I guess the cost of diesel and propane in your area could swing that a little either way.

In this application, the propane is an addative, just like the fuel treatment or NOS.
You are not running the engine on 100% addative, or propane or NOS.
So that means it is not the fuel you are running on.

I also don't know about anywhere else, here the DOT could care less what I am burning for fuel.
But they will get rather excited if I am driving around with a regulator on a cylinder, more so if it is in an enclosed space that would trap any leaking gas.
The frame mounted DOT approved tank, just fine since that is what it was designed for and are not enclosed where leaking gas will be trapped.

So just like you, I am reporting my findings, which do not contain dyno results, but do cover a few other things like safety and cost.