As someone who is disillusioned by the complications of the modern diesel engines with their extremely high pressure common rail fuel injection systems and ever higher turbo boost pressures, I intend to switch back to a normally aspirated petrol engine at my next car purchase.
I know there is no equivalent sized petrol engine that can come even close to the torque of a turbo diesel, but does anyone know where I could get torque curve data for various engines. I fancy a Honda 2.0S Civic, but the maximum torque on that engine is at 5000 rpm, and I would like to know what % of torque is available at say 2,500 rpm, or what other 2 litre petrol engine has good low end torque performance.???
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One of the things I really liked about my Subaru Outback (MY99)
was that the peak torque (225nm) was at 3600rpm with peak power (~150ps) at 5800 rpm. Since niether my wife or I was likely to be driving reqularly at 5800rpm the 'adequate' torque at relatively low revs was a real bonus. Never seen the point of having the peak torque way up near the peak power revs.
StarGazer
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Doubt a honda would suit you, i think they are designed to be revved hard and do not produce much power at lower revs.
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See Page 2 of this link: asia.vtec.net/Reviews/20CivicRev/index.html - you can see the shape of the torque curve, taken from a dyno run.
Torque @ 2500 rpm is quite reasonable in practice: I have a Civic S with about 24000 on the clock. Pity it hasn't a 6 speed box, but its really very tractable, I find.
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Buy an old fashioned classic, preferably one with 6 or 8 cylinders. For example, you wouldn't find a Triumph 2000 lacking in low-speed torque - it will pull from walking speed in 3rd.
Or a Rover 3.5 - you could leave it permanently in top if you really wanted.
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Hi Dude,
I'm not trying to stir it but why does the complexity of a modern diesel worry you? Don't you think that a modern petrol engine is equally complex?
Good luck in your search.
Steve.
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nortones2 - Thanks a lot for your link which was very informative.
How do you find the torque on your Civic S in everyday driving, for example will it pull in 5th gear ok on motorways within the legal limits, or do you have to change down for slight inclines.??
I have also read that road noise transmission is quite pronounced with this model and would appreciate your comments.
Thanks
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You wanr a Boxer engine, so try a Subaru. Twenty years ago a Citroen GS or GSA might have been a good choice.
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"Twenty years ago a Citroen GS or GSA might have been a good choice."
It was (I had one a lot more recently than that) but although it was deceptively smooth, it didn't have huge amounts of torque. Only a small engine (the largest was 1227cc) of course, so it was probably still punching above its weight, but it could rev to infinity, or felt like it. Well, 8000rpm anyway...
I suppose a Lancia Gamma might fit the bill. :-)
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SWMBO has a Civic type S. Performance at the lower end is perfectly adequate, as Nortones says, but not a great deal more than the 1.6. The extra power is at the top end, where iut can't be used so often on British roads.
My diesel Audi with only 500 cc more capacity has 258 lb/ft of torque againt the Honda's 132 - that's what makes the difference. As regards complexity I should say there's nothing between them. Both of ours have been - touching wood - totally reliable so far.
Try a type S and see if it's what you want. It's certainly a lot of car for the money, although for £3000 less you might be happy with a 1.6.
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Sorry Dude - I should have answered your second post as well.
5th is fine on motorways - you don't need to keep changing down: and there's less tyre noise than with the Audi. It's much lower-geared than thew average diesel, but Honda engines are meant to rev and it's quite relaxed at 75-80 mph.
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You wanr a Boxer engine, so try a Subaru. Twenty years ago a Citroen GS or GSA might have been a good choice.
Yup, bucket loads of torque.
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"complications of the modern diesel engines with their extremely high pressure common rail fuel injection systems and ever higher turbo boost pressures"
What problems have you had? - or are you just thinking of what could happen but probably won't?
Phil
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>>>>What problems have you had? - or are you just thinking of what could happen but probably won't?
Phil >>>>
I have had several friends that have experienced premature turbo failures on various diesels, including Honda, Nissan, VW and BMW.
It seems to me that to appease fleet service managers, oil change intervals at 20k on diesel engines is way too long and that combined with excessive heat build up within the turbos is leading to premature failures, - hence my reason to switch to a normally aspirated petrol engine next time around.
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I have had several friends that have experienced premature turbo failures on various diesels, including Honda, Nissan, VW and BMW. It seems to me that to appease fleet service managers, oil change intervals at 20k on diesel engines is way too long and that combined with excessive heat build up within the turbos is leading to premature failures, - hence my reason to switch to a normally aspirated petrol engine next time around.
If you are buying the car, just make sure you have the engine oil changed more regularly. I didn't think diesel engines had such long service intervals, even with fully synthetic oil. The service interval on the C5 is 12.5K
If you are not buying the car, it's not really a concern, I would have thought.
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As someone who is disillusioned by the complications of the modern diesel engines with their extremely high pressure common rail fuel injection systems and ever higher turbo boost pressures, I intend to switch
There is hardly any difference between the complexities of a modern automotive diesel & petrol certainly on the electronic side of things
As far as the rest of the other buzz words like common rail, Ultra high pressure fuel injection pressures, sequential turbocharging, & camless engines,(I hear now that BMW? are comming up with such a sysytem)
I've heard it all before having worked with large diesel plant since i left school in 1975, all this technology is old hat and well proven it's just that the car industry for one reason seem to take a back seat when introducing it
Cummins diesels have had common rail systems since the 1940's
Injection pressures have been going up over the last 20 years some of the pressures in the engines i work on are a lot higher than those on automotive systems
And Sulzer diesels have had a completely camless engine for about 3 years
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I'm convinced that 2 valves per cylinder engines had more bottom end torque than current 4 valves per cylinder designs. My 2 litre 8-valve 306 XSi was much more relaxing to drive than my current 2 litre 16 valve Focus. Much less revving and gear changing required for the same rate of progress.
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L\'escargot.
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I'm convinced that 2 valves per cylinder engines had more bottom end torque than current 4 valves per cylinder designs. >>
That is generally true, simplistically the 8v engine has a smaller inlet valve area therefore the velocity of the air entering the engine is higher at a given engine speed allowing a more effective charge, conversely the 16v with a larger valve area is able to breath more efficiently at higher revs because it is able to suck in a greater volume of air within the period that the valves are open.
My wife's 1.6 8v Clio feels nice and gutsy at low revs and with 90 bhp is quite nippy, the 110 bhp 1.6 is ultimately faster though less gutsy at low revs.
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>> I'm convinced that 2 valves per cylinder engines had more bottom end torque than current 4 valves per cylinder designs. >> That is generally true .....
So why did they make the change? Top speeds are no better, acceleration times are no better. My 306 XSi was every bit as fast A to B as my Focus. And more relaxing as well.
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L\'escargot.
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>> I'm convinced that 2 valves per cylinder engines had more bottom end torque than current 4 valves per cylinder designs. >> That is generally true, simplistically the 8v engine has a smaller inlet valve area therefore the velocity of the air entering the engine is higher at a given engine speed allowing a more effective charge, conversely the 16v with a larger valve area is able to breath more efficiently at higher revs because it is able to suck in a greater volume of air within the period that the valves are open. My wife's 1.6 8v Clio feels nice and gutsy at low revs and with 90 bhp is quite nippy, the 110 bhp 1.6 is ultimately faster though less gutsy at low revs.
Ditto. My 54 reg 1.4 C3 (don't laugh) is 8v but what grunt it has is at low revs. The Almera on the other hand flies as long as you keep above 4000 revs. Which is not always 1 - practical or 2 - safe.
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>>So why did they make the change?>>
Efficiency/emissions, once you want to get more than around 60 bhp/litre then an 8v (or should I say 2v/cyl) is less efficient. And of course marketing.
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>>So why did they make the change?>> Efficiency/emissions, once you want to get more than around 60 bhp/litre then an 8v (or should I say 2v/cyl) is less efficient. And of course marketing. I agree but i think i'm correct in saying that you get better heat dissapation using 2 small valves on you exhaust valves rather than 1 big 1 & less chance of pre ignition especialy with unleaded
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The number of valves has little impact where the charge is under pressure. As I understand it the move to 4-valves enables the injector to be positioned centrally, giving some benefits re combustion/emmisions.
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Without 16v's people won't get the surge as it hits 4000rpm. Surely you know this feeling of getting uptospeedreallyreallyquickly is far more important than actual real world tractability.
;-)
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Without 16v's people won't get the surge as it hits 4000rpm.
With 2 valves per cylinder you don't have to rev the nuts off it to get anywhere. Give me 2 valves per cylinder any day.
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L\'escargot.
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That's my point.
Sorry. I must be still half asleep.
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L\'escargot.
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No worries - I'm on my third filter coffee so feeling slightly more awake now!
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No worries - I'm on my third filter coffee so feeling slightly more awake now!
I drink decaf so I can't say the same!
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L\'escargot.
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The number of valves has little impact where the charge is under pressure.>>
Yes, 4v/cyl has lesser benefit with forced induction such as a turbo unless 100bhp/litre plus is required.
the injector to be positioned centrally,>>
You are talking DI petrol engines there which are still not that common, positioning the spark plug centrally is the normal trick.
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What diesel car has turned you off diesels ?
I'm on my second diesel, and unless they put an extra 10 or 15p a litre on diesel I wouldn't go back to a petrol 'scream-box'.
For what its worth though, out of the petrol cars I've had in recent years, it was the BMW (old shape 318) and the Cavalier SRi 8V that had good low-down torque. It is getting much harder to find these types of cars nowadays due to the multivalve engines (especially Jap cars)which are set up to like high revs.
The only other suggestion, which is contrary to your stated desire, is to get something with a light pressure turbo.
Turbo's really are reliable now, I havent come across anyone I know who has had turbo trouble on cars of the last few years.
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If you change the oil more often than the manufacturers day, then the turbo will last a long time.
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I find the 1.6 16valve engine in my 2001 Fiesta will pull smoothly from 20mph in top.. if you want to. On the other hand SWMBO's 1.4 diesle with 8 valves struggles under 30mph in 4th on the flat.
It's all about power/weight and gearing.
As far as modern diesels are concerned the complexity is such the turbos last 150k + miles with regular servicing and the engines longer.
I fail to see what complexity has to do with the issue of driveability. Indeed I will go further: follow this argument to its logical conclusion and do buy a Triumph 2000 and experienc ethe joys of crankshaft end float at 70k miles due to wear, seizing of half shaft splines when cornering hard, and galloping rust..
No thanks. Modern complexity suits me fine.
madf
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Me too, modern complexity rules. You can keep your grease nipples, carburettors, contact breaker points.
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Ref Triumph 2000, a balanced (i.e. 120 deg even firing order) 4 stroke straight six running a common inlet manifold (single carb) struggles to produce any decent torque because the timing of the respective inlet strokes creates low pressure periods just prior to the next cylinder's inlet valve opening thus effectively reducing the pressure of the air inducted and accordingly the effective compression ratio, this is reduced with twin carbs where each of two manifolds supplies 3 cylinders however it needs complex inlet manifold arrangements to enable a normally aspirated straight six to provide competitive low down torque, BMW manage to achieve this well though others contemporary straight six designs such as the IS200 do lack power/torque at the bottom end.
The Triumph 2000 was nice and smooth though only produced 84 bhp and struggled over 80mph, the 2.5 PI was better though the 2.0 4 cyl Sprint engine was 50% more powerful than the 2.0 six and much more gutsy at low revs even though it had 16v.
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One thing I like about older technology is that I can fix it. I probably can't afford to take it to a dealer who'll plug it into a diagnostics machine, following which he'll tell me there's nothing wrong because there's no fault code or they'll systematically replace components at your expense until/if they find the cure.
This sounds very cynical but from my point of view cars are getting cheaper but the cost of fixing them is scaling new heights. As with electronics, what makes something cheap and easier to mass produce can make fixing it very expensive, for example combined clutch slave cylinders/thrust bearings.
Of course if you can afford it or someone else is paying who cares?
I'll be sticking with the 405 diesel a while yet.
Steve.
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Cost of fixing a problem?
Easy solution. refuse to buy cars from manufacturers with quality/ reliability/service issues.
Almost all the fcats are available. Just look. After all look at diesel chain cam Vauxhall engines - as an example.
Caveat emptor and if the emptor cannot be bothered in this day and age, more fool he/she.
madf
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Almost all the fcats are available. Just look. After all look at diesel chain cam Vauxhall engines - as an example.
Aren't they reliable? Diesel + chain cam should be uber reliable shouldn't it?
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Like any mechanical object some things just wear out. I buy the part fit it job done. Not so easy in these days of specialist tools, procedures, etc.
Even 'quality' cars go wrong.
Steve
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