Diesel vs gas......................
OK folks, there have been a few to many diesel vs gas threads that have shall we say gone to "Hell and a hand basket"! So if all of you would put in you BEST, no flaming reasons for going gas vs diese...
Forum Discussion
On another note many posts back people were arguing more about the power and pulling up hills versus gas mileage. I don't remember the names but we were arguing over turboing the gas engines and how they could be just as effective as the Diesels. Then that got me thinking about why the commercial trucking industry uses Diesel's and why are all the Diesels from Ford, Dodge, Chevy turbod but not the gassers. So I started to research and thought I would post some info incase there were others like me that wondered the same things.
In a gas engine the air and fuel is mixed in the intake manifold prior to entering the combustion chamber. I'm sure most of us already new that. Here is where it gets interesting. When you compress oxygen it heats up. If you have fuel mixed in with that oxygen and you compress it enough it will ignite due to the oxygen heating up under compression. This is why people run injection systems and intercooler on turboed or supercharged gas engines. They want to run more boost to make more power but you have to cool the air/fuel mixture so you don't get preignition. Most of the hotrodders I know running more then 8 -12 pounds of boost are also running an intercooler or some type of injection system to cool down the air before it enters the combustion chamber.
What makes Diesel's unique from Gassers is that the air and fuel is not mixed together in the intake manifold. Only air enters the combustion chamber. The Direct fuel injection system is timed much like the spark on a gas engine is. The Diesel is injected directly into the combustion chamber at the right time. Since the Diesels run so much more compression then your typical gas engine the fuel ignites as soon as it's injected just like a spark plug ignites the air/fuel mixture in a gas engine. Since the fuel and air is seperated you can compress it much more without preignition problems. This is also how some of the new Diesel's start cold without glow plugs. The computer simply retards the injection timing so the air is getting compressed more then normal before injecting fuel. Since it's compressed more it's hotter then on normal starts and thus no glow plugs.
Sorry for the looong post but I found all this very interesting and thought I would share with everyone.
In a gas engine the air and fuel is mixed in the intake manifold prior to entering the combustion chamber. I'm sure most of us already new that. Here is where it gets interesting. When you compress oxygen it heats up. If you have fuel mixed in with that oxygen and you compress it enough it will ignite due to the oxygen heating up under compression. This is why people run injection systems and intercooler on turboed or supercharged gas engines. They want to run more boost to make more power but you have to cool the air/fuel mixture so you don't get preignition. Most of the hotrodders I know running more then 8 -12 pounds of boost are also running an intercooler or some type of injection system to cool down the air before it enters the combustion chamber.
What makes Diesel's unique from Gassers is that the air and fuel is not mixed together in the intake manifold. Only air enters the combustion chamber. The Direct fuel injection system is timed much like the spark on a gas engine is. The Diesel is injected directly into the combustion chamber at the right time. Since the Diesels run so much more compression then your typical gas engine the fuel ignites as soon as it's injected just like a spark plug ignites the air/fuel mixture in a gas engine. Since the fuel and air is seperated you can compress it much more without preignition problems. This is also how some of the new Diesel's start cold without glow plugs. The computer simply retards the injection timing so the air is getting compressed more then normal before injecting fuel. Since it's compressed more it's hotter then on normal starts and thus no glow plugs.
Sorry for the looong post but I found all this very interesting and thought I would share with everyone.
