diesel rpms
9 Second Club
Joined: Nov 2003
Posts: 13,616
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From: Norn Iron
The diesel entries more or less have a free reign as to modifications.
Petrol/Gasoline powered entrants have a load of rules and regulations.
It was a bit like when VW entered a diesel rally car in a few races. Petrol based cars are heavily restricted with a 34mm orifice to breathe through.
The diesel cars had no restrictions.
Teching In
Joined: Oct 2007
Posts: 31
Likes: 0
From: western NY
They are competitive for a few reasons. One being fuel efficiency, but the main one is lack of regulation.
The diesel entries more or less have a free reign as to modifications.
Petrol/Gasoline powered entrants have a load of rules and regulations.
It was a bit like when VW entered a diesel rally car in a few races. Petrol based cars are heavily restricted with a 34mm orifice to breathe through.
The diesel cars had no restrictions.
The diesel entries more or less have a free reign as to modifications.
Petrol/Gasoline powered entrants have a load of rules and regulations.
It was a bit like when VW entered a diesel rally car in a few races. Petrol based cars are heavily restricted with a 34mm orifice to breathe through.
The diesel cars had no restrictions.
Teching In
Joined: Jun 2008
Posts: 9
Likes: 0
From: Columbus, Ohio
In a nutshell, diesel combustion is slow. This is because the air and fuel have to physically mix as the fuel is being injected. A gas engine has the fuel and air pre-mixed so the combustion is much faster.
On the plus side, a diesel is immune from detonation so it can use very high boost, 50, 60 psi or more.
The result is high boost, high torque and limited rpm and power.
Over fueling can extend rpm, as can mixing in some propane with the intake air.
On the plus side, a diesel is immune from detonation so it can use very high boost, 50, 60 psi or more.
The result is high boost, high torque and limited rpm and power.
Over fueling can extend rpm, as can mixing in some propane with the intake air.
In a nutshell, diesel combustion is slow. This is because the air and fuel have to physically mix as the fuel is being injected. A gas engine has the fuel and air pre-mixed so the combustion is much faster.
On the plus side, a diesel is immune from detonation so it can use very high boost, 50, 60 psi or more.
The result is high boost, high torque and limited rpm and power.
Over fueling can extend rpm, as can mixing in some propane with the intake air.
On the plus side, a diesel is immune from detonation so it can use very high boost, 50, 60 psi or more.
The result is high boost, high torque and limited rpm and power.
Over fueling can extend rpm, as can mixing in some propane with the intake air.
Im not sure there is allot of truth in what you just said. Can you elaborate more? Everything that i know about diesels says opposite of what you say, I dont know allot but i do know enough about em to get me in trouble.
You can't rev a diesel engine too high because of the direct injection of the diesel fuel to the cylinder. It takes a certain period of time to inject the fuel and then there is an ignition delay, then a couple of periods of combustion, one rapid the other steady. You can't make the burn process speed up, so if you speed up the engine rpm, you now have less time to complete the burn and not end up wasting most of your power when the piston is already on the downward stroke.
There is a few things that the injector must do.
- Be accurate in the delivery amount of fuel
- Start Injection at the correct time
- Must properly atomize the fuel throughout injection time
- The droplets of fuel that are atomized must penetrate the combustion chamber evenly but not impinge on the surfaces
- Injection must end abruptly and completely
Remember these systems operate up to 15,000 PSI and above. I'm sure some of these systems have to worry about cutting the metal like a waterjet.
Here is a diagram of diesel injection events.
There is a few things that the injector must do.
- Be accurate in the delivery amount of fuel
- Start Injection at the correct time
- Must properly atomize the fuel throughout injection time
- The droplets of fuel that are atomized must penetrate the combustion chamber evenly but not impinge on the surfaces
- Injection must end abruptly and completely
Remember these systems operate up to 15,000 PSI and above. I'm sure some of these systems have to worry about cutting the metal like a waterjet.
Here is a diagram of diesel injection events.
Had my first runaway on friday. That shook me up a little. The manual didn't say **** about where to place the throttle pintle when re installing the HP Valves. Apparently the valves were cranked all the way over to wide open. So when I fired it up, she wanted to take off but I got lucky; it was running SO rich it couldn't rev very easily. (The black smoke was a give away.) I cut the fuel lines before it really took off. Took the valves off, readjusted them, re-installed and she runs like a top now. Gotta change the oil on Monday just in case any fuel made it in there.
http://www.youtube.com/watch?v=7tA52k2CB4E
With a gas engine, the fuel is injected as a very fine mist on the the back of the hot intake valve which aids in atomization. It is also injected slightly before the valve opens, so the cylinder has a nice built up cloud of atomized fuel and air to ingest. The diesel combustion or ignition delay is mostly due to the fact that the fuel needs time to atomize. Which may or may not happen.. I'm not sure.
I work on diesels every day, but I'm transitioning from automotive technology to diesel, so I have a lot to learn.
