Gas engine and Diesel of same specs.Pull the same.

If you are a putting liquid that isn't burning in the combustion chamber, it is basically having the same effect as water injection. Something that isn't burning, can't produce heat. The whole idea behind internal combustion engines is converting energy from expanding gasses to mechanincal energy. If the fuel doesn't burn, there are no gasses to expand and if there is not enough air, the fuel doesn't burn.

Unburned fuel doesn't make power. It just makes smoke gas or diesel.

ROTFLMAO, you need to tell THESE PEOPLE that they are doing it all wrong. Tell them to turn there pump down because in your words "unburned fuel doesn't make power." "It just makes smoke." :R

Here is a PRO STOCK TRACTOR that needs some tuning tips.

I used to race THIS TRUCK all the time. You need to come over here and tell Brad that un-burnt fuel does not make power. If you could tell him how to keep the same power level, I'm sure he would love some tuning tips to save on the fuel bill. :S

The unburned fuel causing the smoke is helping cool the engine, not making power.

Oh brother. :R

Lets try this. Put an EGT on a diesel and then start throwing fuel at it. According to you, the EGT should go down because "unburned fuel causing the smoke is helping cool the engine." :S Lets see how that works out. :S

I do agree with TnP that the turbo has a cooling effect on a diesel that it doesn't on a gas engine. Because the diesel doesn't require a precise mixture ratio to run properly, increasing boost without increasing the amount of fuel will lower EGT's, but higher boost without adding fuel doesn't increase power and increasing the amount of fuel beyond the engine's capacity to supply the air to burn it will just result in black smoke, whether the engine is diesel or gas.

Fuel injection has been standard on gas engines for so long that most people either haven't seen or forgotten the sight of black smoke coming from gas engines with badly adjusted carburettors or malfunctioning float valves.

Yea, me too. But does anyone remember the difference between the 7.3L N/A and the 7.3L turbocharged PSD? Way back in '84, Isuzu offered a NA I-4 diesel and a turbocharged version. There was quite a difference. How about the 3.5L Ford V6 verses the 3.5L Ecoboost V6. More air means you can burn more fuel which means you can make more power. Unburned fuel doesn't make power. It just makes smoke gas or diesel.

Sorry I was gonna say something that I probably should keep to myself.

An engine is an air pump. The only way to make more power is to pump more air allowing you to burn more fuel. There are three ways of pumping more air in a reciprocating engine. 1: Increase displacement. 2: Increase RPM. 3: Forced induction. I don't care how much fuel you pump in, without oxygen it won't burn. Engines and Chemistry 101.

The unburned fuel causing the smoke is helping cool the engine, not making power.

wilber1 wrote:

Turtle n Peeps wrote:

wilber1 wrote:

4x4ord wrote:
It is the turbo that is giving the diesel the high torque output...not the fuel type, but diesels lend themselves much more readily to turbocharging than gasoline engines do. There may be a day that the eccoboost will be king but for now it is clearly the turbo diesel.

Or it could be that diesels are pretty useless without a turbo charger, at least for RV towing.

I've owned several gas turbos and they are great. My present one betters my Cummins when it comes to torque output per liter of displacement and over quite a bit larger RPM range.

I doubt turbo gassers like the eccoboost will replace the diesel because diesel technology will continue to develop as well but I would be very surprised if we don't see more direct injection turbo gassers like eccoboost offered as an option in tow vehicles.

Turbo's on diesels have very little to do with torque. They have a lot to do with cooling the combustion chamber off.

Just look at N/A boat engines where cooling is a non issue. They can lay down a lot of power without a turbo. You want more power? Just throw more fuel at it and give it a lot of cold water.

What! Throw more fuel in without pumping more air and all you get is black smoke from unburned fuel. You do realize that nothing will burn without oxygen.

See what Cat and others puts out with their N/A diesels and you will change your tune. Yes, you can make more power with a turbo on a diesel because you can keep the heat in check, but those that say it takes a turbo to make power just flat out don't know what they are talking about. Just like a lot of people on this very forum that say if you're smoking you're doing nothing because smoke does not make power. :S

So I guess I can't make any power with my gas engine because it has no turbo or O2? :R Diesels can make power without a turbo and so can gas engines.

I have been building and tuning turbocharged engines for over 30 years so I know just a little bit about them.

Turtle n Peeps wrote:

wilber1 wrote:

4x4ord wrote:
It is the turbo that is giving the diesel the high torque output...not the fuel type, but diesels lend themselves much more readily to turbocharging than gasoline engines do. There may be a day that the eccoboost will be king but for now it is clearly the turbo diesel.

Or it could be that diesels are pretty useless without a turbo charger, at least for RV towing.

I've owned several gas turbos and they are great. My present one betters my Cummins when it comes to torque output per liter of displacement and over quite a bit larger RPM range.

I doubt turbo gassers like the eccoboost will replace the diesel because diesel technology will continue to develop as well but I would be very surprised if we don't see more direct injection turbo gassers like eccoboost offered as an option in tow vehicles.

Turbo's on diesels have very little to do with torque. They have a lot to do with cooling the combustion chamber off.

Just look at N/A boat engines where cooling is a non issue. They can lay down a lot of power without a turbo. You want more power? Just throw more fuel at it and give it a lot of cold water.

What! Throw more fuel in without pumping more air and all you get is black smoke from unburned fuel. You do realize that nothing will burn without oxygen.

wilber1 wrote:

4x4ord wrote:
It is the turbo that is giving the diesel the high torque output...not the fuel type, but diesels lend themselves much more readily to turbocharging than gasoline engines do. There may be a day that the eccoboost will be king but for now it is clearly the turbo diesel.

Or it could be that diesels are pretty useless without a turbo charger, at least for RV towing.

I've owned several gas turbos and they are great. My present one betters my Cummins when it comes to torque output per liter of displacement and over quite a bit larger RPM range.

I doubt turbo gassers like the eccoboost will replace the diesel because diesel technology will continue to develop as well but I would be very surprised if we don't see more direct injection turbo gassers like eccoboost offered as an option in tow vehicles.

Turbo's on diesels have very little to do with torque. They have a lot to do with cooling the combustion chamber off.

Just look at N/A boat engines where cooling is a non issue. They can lay down a lot of power without a turbo. You want more power? Just throw more fuel at it and give it a lot of cold water.

4x4ord wrote:


The problem with running a 6.2 gasoline engine at 3200 rpm while cruising down the highway and only making 100 hp is this:

The 3200 rpm is dictating how much air the engine is desiring to pump through it; roughly, 3200rpm x 6.2 liters = about 20,000 liters per min. To make 100 HP the engine can only use roughly 14,000 liters per min so the throttle plate will be run partially closed to restrict the amount of incoming air and therefore fuel .... in a way the throttle plate is performing the job of an exhaust brake, only restricting the intake air instead of the exhaust gas. Ideal for this gas engine would be to slow the engine down more so that it is not working against the throttle plate so hard...it needs more gears.

With the turbo charged diesel engine running at 1600 rpm the turbo will not push an excessive amount of air into the slow running engine but will attempt to ensure there is at least enough air to burn the fuel required to make the necessary HP.

Bottom line is that although 3200 rpm is not necessarily hard on the engine it is hard on the engine's efficiency.

If we're talking about the Corvette cruising 70mph, nowhere near 100hp is necessary. If we're talking about a 6.2L pickup towing, we're all aware of the mileage probabilities. I remember the old F250s with C6 and 4.10 rear ends. They weren't known for efficiency but the 300cid I-6 was known for longevity even with the old technology and inferior oils of that era.