OT: Diesel cars at Le Mans
Posted 27 June 2003 - 01:26
Posted 27 June 2003 - 01:40
Le Mans was always a bit of a stickler for fuels too... maybe, except for the gas turbine efforts, alternative fuels weren't allowed?
Posted 28 June 2003 - 16:30
Posted 28 June 2003 - 23:02
In the early sixties, I was an Army lieutenant stationed at a telecommunications facility in Saran, just outside Orleans, France. As the local civilian power was notoriously unreliable, our backup power source came into frequent use. It consisted of a generator powered by a large WWII surplus LST (Landing Ship, Tank) engine. That monster was several feet high and IIRC maxed out around 800 rpm.
The local "mechanicien" in charge of firing it up was very fond of his vin ordinaire and had a cot where he slept beside the engine. As Duty Officer at night, it was my job, whenever we lost power, to sprint the 25-30 yards out to the generator building and wake him up. Every time I performed this duty, I did as I'd been told and would yell "toot sweet!!" at him in my bastardized French. But he never moved one iota faster than he wanted to, and I eventually learned that my exhortations, though sincere, were counterproductive: it took him about 8 minutes with me yelling and about 6 minutes with me saying little.
That was one big engine, but it would've been hard-pressed to serve as a starter motor for the RBDE!
Posted 28 June 2003 - 23:17
I think we have a cultural difference here.
My (British) understanding is a Diesel engine is one where ignition is caused by compression, as opposed to an electric spark
An Otto engine is any engine that has a 4-stroke cycle, namely
1 Ignition, or power stroke (downward)
2 Exhaust (upward)
3 Induction (downward)
4 Compression (upward)
Most diesel engines are 4-strokes.
Most petrol engines have carburettors to mix the fuel and air. Some, including all modern racing engines, use fuel injection. In some fuel injection systems the petrol is injected into the inlet tract, in others it is injected directly into the cylinders. I think the latter is what you are describing as also being a diesel
A 2-stroke engine (DKW, SAAB, Trabant, some motorcycles) is a valveless engine where the fuel/air mixture is introduced and the spent gases removed via a system of ports in the cylinder walls and in the piston. I have never really understood how it works but it is something like this
1 Ignition (at about top dead centre)
1(a) About halfway down the downstroke a port opens and the exhaust gases are expelled
1(b) At the same time the fuel/oil mixture is compressed in the space below the cylinder
2(a) As the engine passes bottom dead centre the partially compressed fuel/oil mixture is introduced into the space above the piston and displaces the last of the exhaust gases
2(b) About half way up the exhaust port is again covered and the mixture can then be fully compressed.
2© At about the same time another port opens allowing a fresh charge of fuel/air mixture to be sucked into the space under the piston.
Some Diesel engines are 2-strokes
Although inherently less efficient because it is impossible to remove the last of the exhaust gases, because of the lack of valves a 2-stroke can rev very high which offsets the inneficciency.
And to finally confuse things further, although a Wankel rotary engine has no reciprocating pistons it is a 4-stroke engine. I believe that NSU, Mazda, or someone has produced a Diesel (compression ignition) Wankel engine.
Phew! After thinking that hard on a Saturday I need a beer.
Posted 29 June 2003 - 00:06
Posted 04 October 2006 - 19:30
Audi put their own Diesel fuel "Design" to the ACO for homolgation prior to this years 24 Hours.
Normally the ACO supplies the Petrol fuel used BUT not the Diesel....
"So what" I hear you say.
Well the rumour was that there was a small spillage of fuel in the pits.....and it EVAPORATED
I thougth Diesel fuel was an oil.......