Ultimate Engine Config??

[Hilux]

Some of the best sounds I have ever heard was when Mazda had a go at Le Mans you could hear its banshee wail miles away. Similar to a superharged car only better. F1 cars are amazing also. Another was playing golf at Stockwood Park golf club near the end of the runway at Luton airport when a Lancaster took off and the four Merlin engines on full chat 500ish feet above was even louder than a top pro fuel dragster.

Oh..............I think scooby engines sound as if the plug leads are round the wrong way, dreadful.

 

[Fen]

ORIGINAL: George Elliott

Fen, If JCB get the record with a digger engine, the credibility will be theirs. I'm actually very impressed with Roberts awareness of interesting/notable 4 cyl engines. I would rate his credability highly like you own - if either of you asked me to.
None of us are Subaru fanatics, I agree they are unpleasant although the 1600 pickup which I had in 1984 was a very neat handling device with its Flat 4 and low centre of gravity. The first ever Porsche was also a flat 4....
There have been many good 4 cylinder engines in cars which were reliable, quick for their day, and fun to drive.

My own personal dislike among engines is some of the over hyped sports car engines which are excessively heavy.

Great sound though some of them make, good power outputs too, but if they add excessive weight to a car it destroys: Feel, Cornering ability, Responsiveness, Efficiency/Economy, Cost effectiveness, then requires bigger brakes, - that adds unsprung weight, increases tyre wear, needs bigger tyres, adds more weight etc. - One point I admired at Lotus was an awareness of adding lightness, Porsche knew it too and still are among the best in class.

The guy with no credibility (he's definitely not called Robert IMO) drives a car with a big lump of an engine, probably made of Cast Iron, - which puts out greater power than a 20 year old 944 turbo, but carries 200kg+ more weight, which requires 20% more fuel, 20% more braking capacity and needs traction/stability/launch & every other control to follow a 944 on a regular drive in the country when its raining. - The scoobydoo will pester him too, but no - I do not like them. I will admit to having tried to like them[8|].

George

944T

I think you misunderstood my meaning. My statement re: Robert's credibility relates to his assertion regarding sound. I believe that any and everyone who has even the smallest amount of petrol in their blood cares about sound - everyone I know in that category does anyhow.

I don't believe if you reread anything I have written here (or anywhere else, ever) that I have said there are no good 4 cylinder engines. What I said is that 4 cylinders don't sound as good as fives or sixes. As with any generalisation there are exceptions where a particular 4 sounds better than a particular 5 or 6, but as a general rule I stand by my statement.

I also said:
- Large capacity fours are not small or light, which I don't believe anyone has challenged (probably because it's true)
- Very high output fours will not make friendly road car engines - again I don't see a challenge to that

The list you gave of good fours that are "compact, light, practical and quick" includes nothing either large capacity nor very powerful in absolute terms (and while we're here the Renaultsport torqueless wonder doesn't deserve to be in that list).

To get back to the original post topic if JCB take whatever record they are going for with a 4.4 litre turbo four then good for them and they will earn credibility. For a speed record attempt size and weight are not particularly relevant though and hence I draw your attention to the very first words I posted in this thread "horses for courses".

There is a limit to the optimum capacity and hence performance of any engine configuration (as Neil said above - 500cc / cylinder sounds about right; I know 100mm is about the edge of sensible bore from a flame front propagation perspective). That being the case the 4 cylinder JCB must be a very specialised piece of kit and I bet it is much less compact and light than other 4.4 litre 8 cylinder engines for example.

So in summary no, 4 cylinder isn't the ultimate engine configuration. Perhaps for certain purposes it is - if JCB are successful then we have to assume for a time at least that it is for diesel engines optimised for speed records and it may well be for engines of around the 2 to 2.5 litre displacement range, but more cylinders equates to greater smoothness, less weight per cc (multiple small pistons counterbalancing each other versus great big reciprocating masses requiring balancing shafts) etc.

I propose there is no ultimate engine configuration as (horses for courses again) there is a place for many depending on the intended purpose.

Bottom line though; the 944 would have been a far nicer car with a six in place of the 4, and it needn't have been any heavier or less compact to achieve it.

 

[RC18B 911 turbo]

I know this isn't about Porsches but the we've just had the new M3 arrive in work couple of days ago and very good it is too, but although it does sound very nice, very V8ish it doesn't quite sound as good as the straight 6 M3 past 5.5k or quite go like it either, it also doesn't quite look as good either or corner like it too feels too heavy.

 

[Robert Edwards]

My post on this subject was not intended to call into question anyone's knowledge, ability, or whatever. The noise issue (which is less than important to me, because I am usually playing Bach at high levels) revolves about the simple harmonic produced by any engine at a given level of rpm. I am, you see, cursed by having perfect pitch.

I do not care if a car sounds like a knackered cement truck at tickover - I really don't!

It is, however, important to me that when the engine is giving of its best, then it should sound harmonious. It is why I dislike 5-cylinder engines and V10s. Seriously.

The BRM V16 is without doubt an orchestral instrument. I've got a link somewhere. So, in its way, is a decently stressed small capacity V12. But a big four (and I agree generally with Neil Haughey when he mentions the 500cc limit) can also be delightful. Italian stuff.

But there is more than one way to skin a cat - a large capacity oversquare four can also sound glorious at any level, whereas there is something inherently disagreeable about a 5 cylinder engine. Purely on the ear. But a straight six (Aston, Maserati, BMW, even Mercedes) is surely the heartbeat of what we are all about.

I like in line fours for one simple reason. They should be rubbish, but they are not. Granted, there are economies at work, but the simple fact is that there are fewer reciprocating parts (whatever their individual mass) and that, as engineering becomes more exact, allows us to revisit the principles laid down by Bentley in 1919.

Straight Eights? That's a different conversation...

 

[George Elliott]

My father (and a couple of uncles) had Fiat 124's. Early '70's, there are pictures of me with it at the beach in Co Donegal[8D], - all I remember is it sounded great[][][][][] its true, - forgive me, I was only about 5.

I gather there was rust on it the day he collected it brand new.


George


944T

 

[George Elliott]

Summary then.......

I like in line fours for one simple reason. They should be rubbish, but they are not. - I cannot put it better Robert, its exactly my feeling.

Horses for courses, - yep I have to agree there Fen, there is no one size fits all, nor perhaps will there ever be.
Weight, - 4's do have an advantage - you won't find many models where the 4cyl is heavier than the V6 or V8 etc?
Friendly Road Car, - there's a trade off between the benefits of the weightier engine, and the responses of the 4 cylinder - I'd say it was a bit subjective, (more to do with normal v's forced induction??)
Some (like me) will prefer the dynamics of a 944T for example with a light front, and weight balanced rear end to assist traction - but a trickier hi-torque power delivery. Others will be happier with a superb (bmw-m style?) power delivery, and somehow live with a light rear end and excessive front weight in a heavier Car. Great for drifting, don-nuts,etc, but dangerous when driving & not my scene. I hear of M's that have burst the sump on a yump and cases of broken front suspension.

I also follow with interest what M-Benz are doing with their direct inj petrol - the DiesOtto (1.8, 4 Cyl, 230bhp, 290lb/ft, 47mpg) - its in development and it will benefit from compact lightweight design and turbocharging.

New M3, - Jon, they are running out of ideas with that car. I put a lot of the shortcomings down to the engine.

Straight 8, hmmmm got me there Robert, but I'd be interested in the pro's and con's......

George

944T

 

[RC18B 911 turbo]

New M3, - Jon, they are running out of ideas with that car. I put a lot of the shortcomings down to the engine.

I don't just think it's the engine I think the whole package on the whole is flawed the engine is probably the best part of the car, but I think that with the M3 BMW should've stayed to what they do best and that is Straight 6s the 335i is the best car they got on sale at the moment and doesn't feel much slower than the M3.

 

[Neil Haughey]

ORIGINAL: George Elliott

Summary then.......

I also follow with interest what M-Benz are doing with their direct inj petrol - the DiesOtto (1.8, 4 Cyl, 230bhp, 290lb/ft, 47mpg) - its in development and it will benefit from compact lightweight design and turbocharging.

New M3, - Jon, they are running out of ideas with that car. I put a lot of the shortcomings down to the engine.

Straight 8, hmmmm got me there Robert, but I'd be interested in the pro's and con's......

George

944T

It seems to have largely been ignored by most ppl but the latest petrol engines with direct injection etc. have made massive improvements in fuel economy and performance. The current spec BMW 525 for example does 38 mpg combined cycle but has a top speed of 154 mph and 0-60 in 7 seconds.

 

[Fen]

Robert - I am blessed with tone deafness so if there is a subtlety to sounds that is unknown to me then I have to accept your view on it. Taking harmonics out of the euqation then I like the 5 better than a 4, though a 6 is my personal favourite - in any layout. As I said earlier I don't really like a V8 at fully cry that much. Anyhow it seems you also care how the engine sounds which I find much more believeable as you are clearly a petrolhead - and one with a wide and eclectic spread of taste and experience.

George - I can't think of a car that is available with a four and a six of the same capacity to make direct comparison of size/weight. The larger engined variants tend to have bigger brakes and more kit added also which all brings extra weight overall. I would expect any four of huge capacity to have a very specific power band and probably be quite low-revving. The JCB engine I know nothing about aside what has been posted here but my guess is a 4 cylinder diesel of 1.1litres per cylinder is going to have a very low redline and probably make its output across a band of only a few hundred rpm at best and it will simply apply massive brute force to a very high gear to achieve its solitary aim. Not at all a good or friendly road car engine.

Neil - while I'm aware of the new petrol injection technology and that it makes impressive figures like the ones you quote I think it highlights why figures are not the whole picture. As I understand it you can have performance from these engines OR you can have economy, but even more than conventional engines you can't have both. In other words with Miss Daisy in the back you might get close to the stated economy figures and with a heavy right boot you might get near the stated performance, but in the first case you won't be going anywhere fast and in the second you can wave bye-bye to a massive percentage of the mpg the figures suggest. Not a surprise though - these new engines aren't magic, just more efficient, and the performance is down to efficiently converting a lot of fuel into relatively hight output.

I would probably be driving an M3 (e46) if I really liked the engine. I found the sound to be OK, but the exhaust note somehow spoils it and I also found that it masks how quick the car is with unspectacular low-down shove rising very gradually to make the expected performance. Ultimately it's a 3.2 making 343bhp and revving to 8,000 rpm - by the time you get to 8,000 in any gear above 2nd you're so illegal it's asking for trouble so for the road I decided it is not a good engine. I also believe there is a vast difference between individual engines, but that is overcome by driving a few examples.

I've been invited to the new M3 launch and I bet I've left it too late to reply now...

 

[RC18B 911 turbo]

You probably have left it too late to reply for the new M3 thing, nut one of the 2 M3s we got is apparently going to be a demonstrator which is nice to know.

I think that with all the current Mcars they rev too high and produce the power too high in the revs so that would be the likes of the M roadster/coupe, M3 and M5 (this one esspecialy) also the 335i/d is also the same but they are good fun to drive.

 

[Fen]

Ah well - I don't fancy one anyway.

 

[Neil Haughey]

ORIGINAL: Fen

Ah well - I don't fancy one anyway.

Not helped by the fact that the one they gave to the magazines for early test drives etc. had a puke red colour body and tan interior. Looks much better in silver, but then hey how boring is it to have a BMW in silver.

 

[Fen]

I agree - red is not a colour I'd ever choose and it looks especially pants on the new M3.

 

[RC18B 911 turbo]

The red does actually look quite nice in the flesh on the new M3 it's actually more of a mettalic orangy red, but I do prefer the Black one we've got though. Anyway there's nothing better than a red 944 I reckon and I think we are all agreed on that one even the people who don't agree (because I've agreed for them[][]).

 

[sawood12]

Some clever engineer who knows their stuff will be able to draw a chart to show the trade off of efficiencies between cylinders vs. capacity. I suspect that upto 2 litres the in-line 4 cylinder engine is the most efficient, 3 litres a 6 cylinder is probably the most efficient and at 2.5ltrs there is probably a bit of a grey area where 4, 5 and 6 cyinder engines work well. Porsche chose the in-line 4 cylinder engine because it produces less friction than a 6 cylinder engine. I can only assume they also considered an in line 5 but rejected it for some reason.

Just remember regarding the JCB land speed car car being a large capacity in-line 4 it is a diesel - cylinder flame propogation is not an issue for diesel engines as they don't have spark ignition. Also for a land speed car you want a car with a low frontal area so an in-line engine makes sence as it is the most compact when looked at from the front. The reason why they chose 4 cylinders is almost definately due to development costs i.e. they could just use an existing engine rather than developing a bespoke engine for the job that probably has little or no application in any of JCB's products. I wouldn't read too much into their choice of engine.

Regarding sound - for me it is the cherry on the cake - i'd never buy a car for its sound over its performance. I also read that some student did his PHd on the noise cars make and determined that engines with cylinders in multiples of three are the best for sound.m For me the sound of an early aircooled 911 engine is unbeatable - sends shivers down my spine.

 

[Alex Postan]

ORIGINAL: Fen
And 4 cylinders sound rubbish.

Well you must have some pretty crap cars then!

I have a V12 Lambo,
an air cooled 2.7 flat 6
a water cooled flat 6
an Appendix K Lotus twin cam
a pre-crossflow 1650 Ford
a supercharged 962 cc BMC A series.

The A series only revs to 6500 but it has the most character of them all.......the 1650 pulls the most revs though, it's safe to 9000.

 

[Fen]

Scott I think you'l find Porsche chose a 4 cylinder for the 944 because it's half an eight that they had already got in the 928 and that made it cheap.

Alex - I'm not sure the point of your list. Are you trying to show you have more crap cars than I do?

 

[Robert Edwards]

Years ago, on 'Desert Island Discs' a conductor - Hopkins? - selected a Stanley Sedgwick recording entitled 'D types down the Mulsanne Straight.'

It is, I must say, spine-tingling.

 

[sawood12]

You're probably right Fen although that is Porsche's official line.

I think BMW have lost the plot with the M3. It has lost its way and the RS4 has taken it's mantel. BMW have committed the ultimate sin. They released the M3 a good year or so after the RS4 and still failed to topple it and that is despite giving it a bespoke chassis rather than using the 3 series chassis - which is cheating in my view! BMW have no excuse whatsoever for it not being a better car. Still a fantastic car i'm sure, but not the king of the hill any more.

 

[Fen]

ORIGINAL: Robert Edwards

Years ago, on 'Desert Island Discs' a conductor - Hopkins? - selected a Stanley Sedgwick recording entitled 'D types down the Mulsanne Straight.'

It is, I must say, spine-tingling.

I bet it is. Straight sixes as I recall?

Scott - I'm not sure the RS4 is better than the M3, but it's certainly very close which is enough really given that Audi have a reputation for a dead helm and BMW don't. I think the Alpina take on the 335i is a better 3 series than the M3. The common thread here? Turbos. I simply don't believe that with the current hunger for ever bigger power outputs that normally aspirated engines can compete at the cutting edge any more. Now before anyone takes that the wrong way I am absolutely not saying NA doesn't cut it per se, but in the market sector the RS4 and M3 occupy I believe that its day has passed.