Originally Posted by
Blknight.aus
1. its only petrol, it pumps a lot easier than diesel Obvious
2. its only a petrol, the fuel injection pressure you refer to as "high" over here in the diesel world we refer to "low" and "insignificant" to the point where in some engine configurations a total variance of double the stated rail pressure in your supra is inside a 1% tolerance and in some other configurations its around 1/4 of 1% and is so negligible it would be ignored as "probably gauge error or signal noise" The td5 is unit injected, the td5 eu3 series unit injectors inject at upto ~25000psi Not relevant here as we are discussing the fuel that feeds the injector. The pump that creates this pressure is part of the injector.
3. its only a petrol, what you refer to as "injector clearance tolerances" in the diesel world amounts to "the empty supermarket car park you practice circle work in, in haulpacks" these tolerances are needed in all diesel engine injection systems, at the very minimum in just the injector to prevent the injectors from leaking or throwing bad patterns Again not relevant here
4. in some cases the pressure realm in which a petrol engines injectors operate in is the same realm in which some diesel engines look at and go "hmm, the pressure reading on the inlet manifold seems a bit low" and thats in standard trim.ok, this one was a little unfair, I pulled the fuel pressure for the petrol engine from very early throttle body systems where the fuel injection pressure was less than 15psi the stock turbo on the td5 pushes 15-17psi Relevance?
5. I know its not directly related to the fuel system (other than the injectors have to overcome the pressure) but in the petrol world, whats generally considered to be "high" compression over in diesel world is sometimes looked at as "and you got it to start and run like that?" 8-10:1 generally for petrols, 16-20:1 generally for diesels Relevance?
6. in a petrol engine your fuel injection timing is not "critical" missing the injection timing by a couple of degrees wont usually result in pistons trying to turn inside out, non running of the engine or the injector cutting a hole through your pistons combustion chamber. injecting too early in all diesel engines causes diesel knock, do that enough and you'll do all sorts of nasty damage, 25000 psi is in the relm of the pressure used in some low end water jet cutters Relevance?
7. in a petrol engine your fuel doesnt lubricate your injectors, or other parts of the fuel system to the same extent as diesel engines rely upon their fuel to. this applies to all diesel engines. Now this is relevant but only since your last post.
8. petrol fuel systems dont generally rely on the fuel to cool the injectors to the same extent as diesels do, primarily because your injectors don't typically protrude into the combustion chamber. this applies to all diesel engines Relevant to flow.
9. Betting that a petrol engine burnt more fuel is not helping your argument, the basic premise and attraction of diesel engines is that they are inherently more fuel effecient in terms of power produced per liter of fuel consumed. Partly this comes from the fuels density and energy density, which ties back to point 1. excluding cases where you compare a 2015 petrol to a 1940 diesel this generally applies to all diesel/petrol engine comparisons of the same capacity And again this is relevant but not due to fuel usage but cooling..
