Advantages v disadvantages of a diesel!!!

Errrr why???

Despite the higher compression ratio, the diesel cycle

Wrong! It makes that pinking detonating noise because of the extreme cylinder pressures that the high cylinder pressure of compression does to the burn speed. Its why diesels need thicker stronger piston rings sat further down the piston to try and survive it better...

And it does not always work. I have seen many cracked pistons and hammered ring lands on diesels.

Also wrong. companies like vag use the exact same block and crank, with diesel pistons. They are just as subject to wear too as although they have the rings located lower they have the same surface are to wear as the petrol ones. And in addition to the extra cylinder pressures (even at idle!) they are running in what can only be described as a carbon abrasive soup...

Importantly the fuel is also a lubricant.

And the fuel should be burned as it leaves the injector an designed, or you have injector probs. And the result unburned hydrocarbons, acids and gasses goes past the pistons and buggers the oil due to high cylinder pressures 100 percent of the time while running... its why your oil is black almost directly after a service. You are running a more stressed engine in grinding past! You can polish metal using oil from a diesel, easily proven for yourself in ten mins.

Not the ones I speak to - sorry but anecdotal evidence is meaningless....

Absolute bollocks!

I also build and sell dynamometers, and have hundreds of curves from stock cars and bikes, and other than a peaky rs 250 aprilia 2 stroke that is quite simply stupid!.

Why does a power curve have to fall off? If 2 engines mame same power (and torque obviously) at say 2000 revs the one that falls off only loses compared to the one that climbs! Please wake up!

Diesels often need 6 gears or more (trucks) precisely because they lack this very flexibility. They cannot compete here any way at all. You really are va bit clueless here!

But a diesel is just like any normal engine but with the top end chopped off! Thats why people think they are torquey! Its bullshit.

Peak power may be 5 thou redline is overev capability, so you drop back into the power after a change, something else diesls cant do...

Most petrol engines never produce more than 70% of thier peak

Errr why?

Very clearly since I understand what Im talking about.

Aturbo engine of the same cost, weight, cc, torque, will always destroy an oil burner.

Only to bullshit, and testimonials. Totaly open to fact, loigic and ideas. As always.

My gf has one that I bought her in red an estate.

My oil cost me more than that, because I know what it has to do,

Only if you believe the marketing and want to f*ck up your motor. I understand oils and engines, and change my oil every time it begins to discolour. Often every 3000 in stop start conditions in winter.

Obviously you are going to enlighten us why I am wrong?

Oh right! So you are going to explain how "they" do that are you? Because pistons and liners all look bloody similar! They have the same amount of surface area, and are made from the same materials.

Cranks and bearings are all the same too. And some manufacturers actually USE THE SAME ENGINE CRANKASE AND CRANK / RODS!!!

Youy are the numb nuts or rather numb brain.

Because its 13 litre and has a huge slow turning low powered low stressed bhp per litre engine. 500 bhp only from 13 litres! its a boat engine It will run for centuries! And because once out of warrantee the the factory and its marketing department dont care.

And for the same reason a honda 50 or any small engine last about 15 thousand miles. Size.

As does the diesel on induction to a degree but since atmospheric pressure is just 14.7 psi what possible difference can that make!!!

Compared to the huge ongoing compression rven at idle its meaningless, and simply helps the oil to be pulled up towards the combustion chamber further aidind upper cylinder lubrication, and it does this conviniently on overun too.

Stick to truck driving

Its a miserable 500 bhp from 13 litres and built as a heavy (weight not too important for a truck) with a huge filter that obvioslt takes longer to block If the oil is black and it will be you are still causing extra wear over what a petrol version would be doing. They have huge complex filter systems on boats foo for the same reasons but its not practical on a car so not used.

Very wrong. Ask any deisel owner to dip the oil and look at the colour! Gold it is not!!!

Localised heat around exhausts valves etc caused by bad injector patterns after a few miles, . vibrations in crankshafts cauing faster bearing wear and crank faliure on occasions (attempted cures such as crank dampers help but you are treating a symptom of the knocking thats happening all the time. cam drive trains wear faster due to the high compression giving a less smooth idle, too much slowing and speeding up over top dead centre, piston ring cracking due to the constant knocking, even though to help stop it they fit less efficient thicker rings further down the pistons, which in itself causes further issues... Etc.

Err above to begin with, not including periferals that dont suffer the added vibes well, or turbos the cook the carbon out of the oil and die of oil feed bearing problems, you want more??????

In this post?

You don't dispute my summary of how you've got to the point we're currently at, for one.

Secondly, I can't say it enough times... *open your eyes*, and look... an abundance of high mileage diesels are out there, still being used reliably by all and sundry.

I've rarely had problems in an engine sense, with any of the numerous old clankers I've bought (several with over 200k under their belts), and then run (in all probability), harder and faster than they had been prior to me getting them.

If anything, it's been the chassis bushes etc., on said cars, that have shown the side up, and have also gone some way to proving your average old diesel owner hasn't been that attentive when it's come to maintaining the bloody thing.

Except I've done more than you in this respect, as in I've gone out and bought a few, and then almost certainly subjected them to much more duress than others would do, given the same car, at the same time in its life, and with the same miles under it.

I'm not saying you're 100% wrong on all the original points you raised, but unfortunately, you've clouded anything valid, by way of your inability to concede anything that doesn't quite tally with what you wrote, even when numerous others have bothered to labour the point(s), with you.

You mean you refuse to accept that for most of the population, most of the time, there is no detrimental performance impact found when switching from petrol to turbodiesel.

Since most of the population consider equivalent cars to cost around and about the same (be this considered fair or otherwise), I don't see your issue. It's great that you prefer petrols, that's really good, but don't try to tell everybody else that what suits you is what suits us.

It's certainly not gold in our petrol car, what's your point?

If diesel engines are so unreliable, why to thousands of taxi drivers use diesels?

That statement just proves you don't have the slightest clue.

NOTHING to do with the thread read post one which remains true.

Cost has nothing to do with any of this, see my post, that is something deseaselers keep going on about, it is not relevant.

That there is a huge difference in the time this takes as you well know.

I didnt post that. Your confusion continues.

The tread goes about "Advantages v disadvantages of a diesel", not about detrimental impact found when switching for petrol to turbodiesel.

In a switch of roadcars that detrimental impact is bollocks anyway: you are not in a competition where you can verify and when a normal person switches car there are a lot more parameters that change.

When you go from a 2000 90 HP petrol car to a 2005 150 HP turbo-diesel that the increased perfomance of the latter is not due to turbo-diesel but to 5 years of extra research and the money you've pumped in. In the little country where I am living the 5 years also means 5 years extra on legal theft engineering also known as taxes...

Once again : that's not the thread. Burgerman explains clearly and technically that petrol engines have a performance advantage over diesel engines and he is right in such manner that there is no discussion about it.

What shocked somewhat is that some self-declared specialists with a big "sig" in this newsgroup don't actually grasp the technical underpinnings of engine design / performance. That's a pity because then one ends up with "performance parts" like blue underbody lights.

I am fortunate enough to have a lot of cars (not quite enough though). Diesel in my area cost 1.1 Eur/l where 98Ron petrol costs 1.45 Eur/l. My personal vehicles (all petrol driven) costs per km about 50 Eurcent to drive (all costs included) but my company cars (there are petrol AND diesel company cars) earn 70 cent Eurocent per kilometer.

So take the car you need for the job: take a fast petrol car when you want to enjoy yourself, take a diesel trolley when you are going shopping. If you don't have the luxury of swapping cars, take the one on basis of what you need not on what you like: a Caterham 7 is nice but bloody awful when it is parked outside in winter with you needing to start it at 06Hr00 to go to work...

As for what suits you, Burgerman nor anybody will be able to tell you that: we don't know your situation and it has to be supposed that you're grown up. ;-)

Just my 2 Eurocents.

Tom De Moor

Out of interest Conor, what size engine is that, what are the peak torque/power figures and how much oil does it take to fill to max?

And how long do they last before needing major work i.e. turbo/high pressure fuel pump/any other engine internals?

a couple of barrels, with much better filtering than any car...

How long is a piece of string...

I asked, as Conor may well actually know the answer, as he drives the things.