How did diesel buses and taxis cope with short low speed journeys in London?

[Pete WhiteParticipant @petewhite15172]

Posted by Andy Stopford on 27/03/2023 19:39:18:

I own an FX4/Fairway, the predecessor to the TX series cabs. It was one of the last built and has the 2.7 litre Nissan TD27 engine. Earlier FX4s had an Austin diesel, and after production of that engine ceased they used the Land Rover diesel, against the advice of Land Rover's engineers who felt that it would not stand up to taxi operating conditions. .

Interesting info there Andy. I fitted one of those 2.2 Austin (BMC? ) diesel engines into a landrover, with the LR gearing it was the slowest thing around these parts for miles. It was the cheapest LR replacement engine, if the series wired heater plugs circuit was ok, you were good to fire up in winter, not a good idea in series one out all out. Had one engine with an inline pump with cold start you, were always good to fire up in winter…….quite a bit of smoke though

Replaced the 2.2 later with a BMC 2.5, better, but not good, at least the heater plugs were wired in parallel

Pete

Edited By Pete White on 28/03/2023 16:45:20

[SillyOldDufferModerator @sillyoldduffer]

Posted by Nealeb on 28/03/2023 14:38:55:

I wonder how much difference the newest generation of hybrid buses will make? A bit odd the first time I rode on one; silent take-off from the stop with the engine only starting once we were rolling. I assume that this is to avoid the black smoke effect pulling away from standstill but I guess it might also make a bit of difference to engine life by avoiding so much operation in the carbon-forming regime?

They use two complementary technologies for best effect. Internal Combustion engines are low torque from starting, calling for high rpm and a bit of clutch slipping to get the vehicle moving. IC is inefficient and dirty until it gets to cruising speed. With my inner boy-racer locked in the boot, I get much better mpg at a steady 55mph on motorways than I do in cities. Hills and heavy acceleration and braking have much the same negative effect. Electric motors have much higher starting torque and better acceleration than IC, and they're clean. So it pays city vehicles to pull away and accelerate up to speed electrically, and then kick in IC to cruise at optimum rpm with minimum emissions.

An interesting variant is a Hybrid configured for performance rather than fuel economy and low emissions. On a motorway, no speed cops in sight, possible for a hybrid to leave an IC only sports car in the dust by engaging the electric motors as well.

Lack of hills and heavy acceleration are factors in the long-life of London taxi engines too! As engines go, they're mileage rather than high-stress. Formula 1 engines are rebuilt after every race…

Dave

[Howard LewisParticipant @howardlewis46836]

A very successful repower was to fit a Prkins 4.203 in place of the L R 2 or 2 1/4 litre engine.

Apparently did wonders for the fuel economy!

At C A V we had a long wheelbase L R with the largest wheels and lowest axle ratios, attached to the proving lab..

In thiose days it would outperform almost anything larger, and being high (The front bumper was about level with the boot lid of most cars ) terrorise anything smaller..

(The exception was the Dennis tractor and trailer useed by Rolls Royce to deliver parts, overnight, to the London heasquarters. It had been fitted with a 250 bhp K series engine with Allison automatic transmission. From 0 – 30 it would give a Jaguar a hard time!)

On a cold morning, at tick over, the L R suffered light load misfire, but was OK when on load.

I preferred it to the BMC J4 which obviously had heater plug problems and was a pig to cold start

THE epic cold starter was the Perkins Prima which would start unaided down to -5C, but that came years later.

[Justin ThymeParticipant @justinthyme24678]

I remember driving wagons back in the late 70s. didn't all have night heaters back then, used to just let them tick over all night during the winter. Would blow a lot of smoke for the first few miles the next morning, then they were fine.

Remember one, it would burn the best part of a gallon of engine oil every day, boss used to give me used engine oil out of the newer wagons to save money, think it had done something like a million and a half miles. It would have been interesting to see the inside of that engine.

I doubt modern day high performance diesels would have such longevity.

[Pete WhiteParticipant @petewhite15172]

Posted by Howard Lewis on 28/03/2023 17:18:41:

A very successful repower was to fit a Prkins 4.203 in place of the L R 2 or 2 1/4 litre engine.

Apparently did wonders for the fuel economy!

A couple of mates "went big" with those 3.3 litre perkins, did not do wonders for the gearbox and half shafts lol. They did have big biceps though, strugging with the manual steering and lack of turning circle

Pete

P.S. Yes, cold starting was a problem with early diesels and non winterised fuel on journeys in the cold. Lots of utube vids of diesel loco starting from cold, not a pretty sight…..

[Andy StopfordParticipant @andystopford50521]

Yes, I was warned not to substitute a Perkins 4.203 for the very tired Rover diesel in my Series 2a Land Rover if I wanted to use it for anything practical. I ended up getting a recon Rover diesel and it served me well – I was careful to treat it kindly though, you couldn't thrash them like a Toyota Landcruiser.

Cold starting performance varied a lot between manufacturers; AECs were generally regarded as better starters than Leylands for instance. When I was young and stupid I part owned a 1954 AEC Reliance service bus. If there was enough charge in the batteries to turn the engine through one compression it would always start. Unlike the (indirect injection) Perkins P6 I fitted to a Commer Q4 lorry, which needed an aero engine-like starting procedure with precisely timed manipulation of Kigass pump, pre-heat, accelerator and starter button.

By the way, the first high-speed diesel for road vehicles was invented by Perkins, or rather by Frank Perkins' associate whose name I think was Chapman. They had met working for Aveling Porter in Strood.

[noel shelleyParticipant @noelshelley55608]

Perkins 4203 in a 2a or S3 landrover and overdrive box, powerful but not fast, 55- 60mph, easy to start with the thermo start unit – wonderful ! Perkins prima, always started, put it in a boat, great, often crossed the Wash for a day at Skeg. Then there was the champ, disable the ignition cutout and it was good for about 90 – now that DID make a landrover look old fashioned ! Cambridge estate with a tuned MG B engine and overdrive, that caused a few to sit up and take notice ! Noel

[not done it yetParticipant @notdoneityet]

With my inner boy-racer locked in the boot, I get much better mpg at a steady 55mph on motorways than I do in cities.

Dave,

Should you really be doing that speed in the city?

I’ve recently been getting over 47mpg from our 2.2 diesel auto 607 on a long run. It does not smoke even after 175k miles. I have never yet topped up the engine oil, in the three we have had, between changes. Likely a little fuel dilution in each 20k miles between services, but oil still on the dipstick full-mark.

I will shortly only be left with the Pogo 106 oil burner (the big car has, effectively, been replaced by a BEV), as my run-around skip.

It is difficult to work an auto that hard. Yes, I can hold it in a lower gear, but the engine is never going to be heavily over-loaded and it will rev past the obvious gear change point by quite some margin. They recommend an ‘occasional’ 20(?) mile run at around 50mph in order to regenerate the DPF, that is all.

[Pete WhiteParticipant @petewhite15172]

Posted by noel shelley on 28/03/2023 20:39:05:

Then there was the champ, disable the ignition cutout and it was good for about 90 – now that DID make a landrover look old fashioned ! Cambridge estate with a tuned MG B engine and overdrive, that caused a few to sit up and take notice ! Noel

Austin Champ 2.8 Rolls designed engine, traded a few of those….for our own use we went diesel, petrol at 10mpg was not funny even then, Standard Triumph2.2 engine and gearbox, champ had rear transaxle which sent power with a lower propshaft to the front axle. Went to Saint Tropez in that……… to "see the sights …

[blowlampParticipant @blowlamp]

Not exactly about the original poster's question, but I enjoyed this related video which appeared in my suggested viewing list.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Justin Thyme on 28/03/2023 17:27:30:

…

I doubt modern day high performance diesels would have such longevity.

Car engines aren't designed for longevity. They're intended to last as long as the rest of the vehicle, about 120,000 miles or 15 years-ish, to deliver good fuel economy and performance, and – more recently – reduced emissions.

Longevity is achieved by over-engineering, resulting in heavy engines with poor fuel-economy and reduced performance, which most owners don't want! A less obvious disadvantage of long lasting engines is they aren't future proof – buying an expensive heavy long-life engine to last 50 years isn't smart when fuel-prices are rising and congestion zone charges are being introduced.

Couple of extreme examples:

• In the science museum, the oldest rotating steam engine in the world, James Watt, over 200 years old and still in running order. It's thermally under loaded; the engine weighs about 15 tons and delivers a maximum power of about 14HP – less than 1HP per ton, efficiency about 2.5%. Even though the materials and construction are low-tech, the engine has excellent longevity – better than an IC engine. But note the disadvantages – the engine is far too big and heavy to power a vehicle of any kind. And the weight doesn't include the boiler, which had much shorter lives than the engine.
• In sharp contrast the 5 motors used by the first stage of the Saturn V rockets to launch Apollo missions each output 11,000,000 HP for a weight of 0.0016 pounds per HP. But only for a few minutes, after which the engine is toast and the entire first-stage structure is done for.

Comparative lifetimes of modern engines, approximately:

• High-performance petrol – about 1000 hours. (Low performance road cars get more.)
• Jet engine – about 4000 hours
• Large diesel (ships, not lorries!) – about 60000 hours

The diesels fitted to ships only have to last slightly longer than the hull and other equipment. While the ship is operational, fuel-economy and reliability are the top priorities, not that an old engine will still be running after 20 years service.

Dave

[duncan webster 1Participant @duncanwebster1]

My last 3 cars all did 150k plus miles and were still runnable when I sold them. Nissan Bluebird petrol, written off in motorway accident (not SWMBO's fault). Vauxhall Vectra petrol, government scrapoage scheme, still a very good car, but they offered me a lot more than its value. Skoda octavia diesel, given to #2 son, now traded in.

By my choice of cars you'll see I'm not a boy racer, they all still had original clutch and exhaust, only replacement bits cambelt and brakes apart from normal consumables.

Edited By duncan webster on 29/03/2023 14:26:11

[simondavies3Participant @simondavies3]

I sold my 22 year old Audi Quattro A6 estate to a friend last year – diesel, 465k kms on the clock, still going strong – only sold it because some of the trim started to time expire – especially some plastic parts permenantly exposed to the sun.
In my 10 year ownership, I drove a mix of 1000-1500km trips and local trips.

Built like a brick outhouse, bought a newer one to replace it with only 250k kms
Simon

[noel shelleyParticipant @noelshelley55608]

Pete, If you thought the champ was bad, I also ran a Humber 1 tonner, 4.2 rolls built B series. Now that did use a bit of fuel(petrol). Superb suspension and quick up to cut out at 60mph.

Back to diesel, LARC XV – 2 X 15L v8s, great fun to drive. Now thats what I call driving.  Noel

Edited By noel shelley on 29/03/2023 17:10:35

[Pete WhiteParticipant @petewhite15172]

Posted by noel shelley on 29/03/2023 17:07:42:

Pete, If you thought the champ was bad, I also ran a Humber 1 tonner, 4.2 rolls built B series. Now that did use a bit of fuel(petrol). Superb suspension and quick up to cut out at 60mph.

Back to diesel, LARC XV – 2 X 15L v8s, great fun to drive. Now thats what I call driving. Noel

Edited By noel shelley on 29/03/2023 17:10:35

That was a Roll 2.8 engine with two pots added Now that wouldn't fit a Landrover.

If it goes on like this I will be mentioning my Series one rag top, with Rover V8 added. Sales reps in cavaliers etc. used to pull alongside and wonder where I had gone when the lights changed to green lol. "Those were the days my friend I thought theyed never end" , thats a song I believe?

[Howard LewisParticipant @howardlewis46836]

The Prima was intended to mlast. TRwo came back to the factory as taxis with 3000,000 on the clock

An industrial version (500 Series) did 7,000 hours in a fork truck and the bores were still within new tolerance.

The P6 was not the best of cold starters, the 6.354 being DI was much better.

Once, visiting Peterborough in the early 60s, I travelled in a 4.99 powered Ford van. Next morning having started it, I watched petrol cars being towed to start! Got some grudging looks!

I chose the Ford instead of the BMC J4 darkroom van, which dislike starting at any time.

Howardl.

[vintage engineerParticipant @vintageengineer]

The Mercedes 240D was built for taxi work and would easily top a million miles before it needed any engine work.

[noel shelleyParticipant @noelshelley55608]

Yes Howard, the 6.354 was a good engine, but the ford York was a problem, even to Ford. Noel.

[Howard LewisParticipant @howardlewis46836]

At CAV I did some work oin the Ford Dorset, 360 in^3.

In my mind it was already smoke limited before any need to muprate to mkeep a good place in the market.

Attempts at turbocharging it were horrific. One threw a rod while the tester was in front of it (Thankfully ). The only thing holding the front and back halves together was the cylinder head.

If you were lucky a head gasket would last long enough to complete a power curve!

We never did get the bits out of the celotex tiles in the test cell

Before production, it was derated to 150 bhp from the "wish list" 180 bhp (40+ percent uprate? Oh come on! )

At least I did get a nominal 300 bhp out of a marinised 6 litre Perkins !000 Series, as a limiterd life engine. After 50% more than the published life, ik was as good as new when we stripped it!

Peterborough could build a mix of naturally Aspirated, Turbo charged or Marine engines down the same track Dagenham needed four tracks to achieve that. They did use single spindle yield tigthening before us, though!

Our machine tightened all 32 bolts at once. Finger tight to a 9 nton tensile load in 7 sceonds. Awesome!

Howard

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