Thread: Is Bigger Really Better?

Originally Posted by CaverD3

Exactly.
Most who are buying the 'new' Tojos are buying them because they think; "There is no substitute for cubic inches."
TDV8 is 4.5 litres gets the same torque as the Land Rover TDV8 and the torque curve is flatter. Land rover do it with only 3.5 litres.
In fact you can get close to the Tojo figures by re-mapping 2.7 TDV6.
The Tojo engines are also failing using oil and burning out valves.
LC200 is not much different from the 100 exect the engine and KDS.
The 70 series is based on a very old Prado (one we did not get here) they just widened the front track to fit in the V8 and no facility to fit airbags so they don't have them!
But Toyota market them as 'new model' implying you are getting an improvement on the old ones.

With modern engines you don't need the capacity to get a good tractable engine.

I guess thats if you're talking outright power and torque, but take the Nissan 4.2TD and 3.0TD. Both have similar power etc, but where the CC's shows is when lugging - the 4.2 has torque, the 3.0 has stall. There is no chance in hell that any LR diesel that I've had anything to do with has to total lugability that the old stinky dog of motor that Toyota call the 1Hz has. The Isuzu is the exception. The 1Hz I generally dont even rev to over 2500rpm, where the TD's dont even start making power until just under 2000rpm.

I would not call the Nissan motors modern diesels. So that is why the difference in cc will make a difference to the torque.

Originally Posted by CaverD3

I would not call the Nissan motors modern diesels. So that is why the difference in cc will make a difference to the torque.

So you're saying that the whole reason behind this is because you don't consider Nissan diesel motors to be modern? Surely there's a more technical explanation.

Having looked at this thread I see there are two factors being confused. These are the need for power - whether we need a couple of hundred horsepower to do what Series landrovers did on well under a hundred (and with speed limits generally lower than they were thirty years ago), and the spearate question as to whether this extra power can only be gained by increased engine displacement.

The first question is simply a matter of where your priorities lie - the more powerful engine, everything being equal, will be heavier, use more power and cost more, but you are making the decisions. Driven exactly the same the fuel usage will not be very different and could go either way, but the more powerful engine will encourage driving that uses more fuel.

As far as the second question goes, for diesels at least, it is possible to get exactly the same power and torque distribution over a wide range of capacities, simply by increasing boost and fuelling. The unsupercharged engine does not have this option, so the only way of changing the power output other than fairly marginally is to use higher rpm or increased capacity. With the supercharged diesel, boost and fuelling can be increased to give any desired torque at any rpm within the designed speed range, limited only by structural strength, cooling and turbocharger size, so in this case it is incorrect to say there is no substitute for capacity.

The main reason that parts for the "new" engines are so expensive is that for the "traditional" designs, the basic design and development was done many years ago, and the cost of this is amortised over perhaps fifty to eighty years of production. New design engines that incorporate newly designed parts (such as, for example the TD5 injectors) have only a few years production to cover those costs (and usually the patents are still current and there is only one manufacturer, so no competition (compare for example Bosch injectors with interchangeable parts made by Nippon-Denso).

John

The answer lies in the application required

Towing a caravan .... Cubic horsepower is better
Climbing a mountain .... The gears & the cubics you have should do it
Touring ... Maybe a bit more H/P ... But there's enough to be comfortable
Passing traffic in the country .... Falcon XR8 is great mate

Cubic size is better as it limit's the stress factor on the engine for a better H/P output ... Where as a smaller motor with higher specs is liable to run hotter and have more internal motor stress which = issues

However ...upgrade the motor ... and you will have to upgrade the drivetrain to suit // Just have a look at some of Rovercare mods and the damage done

Mike

My ideal diesel engine would be a straight six indirect injection, NA with inline injection pump, massively ridiculously undersquare of about 5,000 cc.

John, your 2nd paragraph contradicts your 3rd.

Originally Posted by rijidij

I own or have owned and driven, 3.5 V8 auto RRC, 4.2 V8 County and I recently bought a '99 Td5 Defender, but for me, my Isuzu 4BD1Turbo in the County out shines them all. The Rangie is comfortable, but simply guttless for the amount of fuel it uses. The 4.2 in the County was a fantastic motor, plenty of go on the road and excellent torque down low off road, but used too much fuel also. I've only had the Td5 a few weeks, and I must admit I am impressed with the on road power it has for a little 2.5 litre motor (even if you do have to rev the crap out of it) and the fuel economy, but it lacks torque.
The 3.9 litre Isuzu Turbo (intercooled) would give my 4.2 V8 a run for it's money on the road and as good as the 4.2 was off road, the Isuzu is better.
Compared to the Td5, and regardless of it's apparent reputation as a 'harsh' motor, the Isuzu is more relaxing to drive, and you don't have to ring it's neck having an abundance of torque along with great fuel economy. And with 500,000 kms + between rebuilds (and that's when they've pulled 7 tons GVM all day, every day) it's cubic inches and no electronic crap for me.

I agree with rijidij - i have owned 2.25 Landrover petrol and diesel engined series vehicles, Stage 1 V8 109, 2 3.5 lt Rangies (both 4speed manuals); 2 300Tdi defenders, 1 300TDi disco (still do), and now the Defender with the 4BD1T - it leaves all the others far behind, for smooth relaxed long distance capapbilities, fantastic offroad performanace and great as a tow vehicle, and all combined with bullet proof reliability without electrickery.

Simplicity, capacity, and inherit toughness will always outlast light duty engines in almost any application

FWIW

CHT