Please explain this difference between diesel and gasoline engines

[DarkBlack]

No, it is not. The deposits are from exhaust which exit the intake valve as it initially opens.

So now those detergents are placed in the motor oil and rely on the PCV system to deliver to the intake valve.

Sorry to break it to you, but the rest of the automotive world agrees with me.

 

[dfkrug]

Plenty of other manufacturers have gasoline engine designs taking advantage of multiple DI events to create incredible torque numbers.

Pretty much all of the majors do that now, as far as I hear.

Multiple DI events, variable valve timing and lift, and super high compression ratios have made small 4-cylinder gasoline engines produce very high horsepower at relatively low RPM. Adding turbochargers allows for 150hp+ per liter, often on regular gas.

Most big makers have 2-liter 4-cyl gas engines that put out greater than 300hp now. It is becoming the new "standard" engine.

 

[Racer4]

My car has both port injection and Direct Injection. The port injection is used in lower power situations, cruising, and provides a cleaning to the back of the intake valves. The direct injection is for higher power situations like full throttle acceleration.

 

[Grumpycat]

Sorry to break it to you, but the rest of the automotive world agrees with me.

Then all you have to do is vent the PCV to the atmosphere and never again have dirty intake valves! But that doesn’t work because the deposits come from exhaust gas exiting the combustion chamber back through the intake as the valve opens.

But it is so easy for those who “think” but never do to believe intake valve deposits come from oil vapor in PCV gas.

 

[Riding a Relic]

[Yes, Cloaking is and issue from Exhaust Gas Recircalation, but it isn't limited to Gasoline Engines. Diesels also Recirculate Exhaust Gasses.

However, Newer DI Gas Engines have combated this with Dual Injection, washing the Intake Port. Diesels have yet to accomplish this. But most of the Diesel EGR gets clogged in the EGR Cooler before the Intake Valve.

Diesel fuel produces more torque, down the long cylinder, than gasoline does, simply because it burns slower. In the tractor world, torque is king.

Diesel does burn slower, but that isn't all that creates Torque, It's Energy Potenial is there long before Ignition.

Chemical reactions (oxidation)

Material	Specific energy (MJ/kg)	Energy density (MJ/L)
Diesel fuel	45.6	38.6
100LL Avgas	44.0	31.59
Jet fuel (e.g. kerosene)	43	35
Gasohol E10 (10% ethanol 90% gasoline by volume)	43.54	33.18

But the Internal Combustion Engine regardless of Fuel Burnt/Used, is still very Inefficient, 20-40%, the rest is unused Heat, Friction, Reciprocating movement, and so on.

Direct Injection (Timing and Atomization) helps in both cases/fuuel, but at a price

Yes I know. I was a manager at a fleet of IH with the 6.4 L engines. Seen a lot of intakes have to come off. Also other problems associated with the EGR systems on the Cummins as well. I am no stranger to modern diesel engines with electronic control, and Freightliner runs EVERYTHING through the PCM or BCM. You hit a switch, you are asking the module to turn on the feature you need to use at the moment. Some of those systems had 11 modules, all multiplexed on a CAN bus. Another thing, at the time, they would loose a module, but would only tell you that you had a node offline. Not tell you which one.

 

[Riding a Relic]

A diesel engine was originally named a heat engine, for obvious reasons.
A diesel at low idle uses practically no fuel, incoming air is compressed by the turbocharger, air compression keeps it turning for the most part.

For your reading pleasure: Diesel Warm Up & Cool Down Considerations

Most turbochargers do not generate boost pressures until they reach a certain RPM spinning up. At idle it is not apparent.

 

[Riding a Relic]

Sorry to break it to you, but the rest of the automotive world agrees with me.

So, are you a tech or an engineer, what do you do for a living?

 

[D'oh]

The fact that one never seen Intake Cloaking on say a Ford 3000 Massey 135 Diesel, points to PCV/EGR (They had none) as the Culprit, not Direct Injection or Valve Timing (Exhaust Escaping on Intake Stroke) The Cylinder is under Vacuum when the Intake Valve is Open.

Yes it is possible that some Carbon could travel up the Intake but without the Oil Glue Sludge, the Carbon was just Sucked In for the next cycle.

 

[YanmarFever]

The difference between a diesel and a gasoline vehicle is about 8 thousand dollars...

 

[stumblinhorse]

Really good discussion on the difference in this video.