a real fuel saver - diesel conversion for petrol engine

probably cheaper to buy another cheap runabout.. like a maxima Ti from auctions with electric everything, cruise control V6 Auto, for $2300... sweeeeeeeeeeeeeeeeeeet.... and its a nissan

it is not a fuel conversion, it's a conversion to run petrol in a converted diesel engine so that you dont need spark. my new question is, there is obviously a point where the petrol combusts itself without spark, why then are petrol engines designed with plugs?, why dont they already diesel?

“System uses pistons modified to carry a “chemical charge” that initiates combustion from one cycle to the next, thus eliminating the need for spark plugs. High compression, typical of diesel”

It never say’s that the Chemical charge is in-fact petrol, it also say’s that it would run on a lighter fuel such as ethanol or a heaver fuel like Bio-diesel Indicating to me that petrol ‘ULP’ as we think of it would be eliminated from the equation

“The piston head is designed with micro-chambers (MC) containing small connecting holes to the main combustion bowl in the piston. The initial combustion is brought about by the use of glow plugs which are turned off after starting. When fuel is directly injected into the engine at a precise moment, the SCAI design allows a small portion of the fuel to enter the MC.
This allows a slow chemical reaction in the MC which continues into the next compression cycle, thus providing the “chemical spark” for the next combustion.”
So it is still using a outside source (If you could call it that) To keep the cycle ticking over after the glow plugs are disengaged.
To the best of my knowledge (I have never been told different) petrol is not self-combustible it need’s a initial burst of energy to start combustion, as this engine utilises. If buy some outside chance it is in-fact self combustible I would think that the compression needed to make it ignite would be far to high to be feasible, thus why it has never been implemented.

Sorry I must stand corrected petrol must self-combust eventually but the amount of compression needed to achieve this would be too high. The energy needed to compressing the fuel enough to make it ignite on it own would most likely take to much of a % of energy created by the combustion of the fuel there for leaving very little energy (Power) to propel the vehicle after taking into account energy lost thro friction and exhaust heat.

i was of the opinion that pinging is in fact petrol exploding before TDC, and the reason it exploded is because the compression of the engine was to high, say 10:1. this is the reason for higher octane, the high octane allows modern turbo engines to compress the mixture more with out early detonation. so this denotes you can diesel a petrol engine. perhaps its a little less reliable but i doubt it. also someone on this forum once said the diesel equilavent to petrol octane would be about 130, meaning if you have octane petrol of 130 you could put it in a diesel. so i recon you could run a petrol engine while dieseling, but why dont we? it is obviously an efficiency thing.

Yes you are right where is my brain , could it be that detonation will not happen under all conditions, also the new Falcon engine has a compression of 9.8:1 and run’s on regular unleaded the Turbo has a compression of 8.7:1 and V8’s sit somewhere in-between so a fuel that will self combust on one may not do it on the other.

If you get what I am saying not every engine will detonate if filled up with the same fuel and run under the same conditions, if you had 10 cars the right conditions for detonation to occur may only happen in 1 or 2 and even then maybe only 3 cylinders out of say 6. Let’s not forget that detonation is extremely bad for engines and getting it to happen at the right time and for a smooth burn to happen and not have the pistons pushed back down the wrong way is probably near on imposable.

yeah i hear what your saying with all that, but what about diesel engines. you can use bio diesel, plain old fat (it will run for a while on a standard diesel) you can run full fossil or anywhere in between, you can also swithc and change from good to poor quality brands. a diesel will always detonate properly, i cant recall ever hearing about a diesel pinging, so again, i still think my questions is valid, why not diesels using petrol??