Best engine

[Daan]

are you in the wrong gear?

[Ex Member]

36 minutes ago, deep said:

and even normally aspirated 2.5 diesels.

From idle until when the turbo produces boost, the torque is almost identical to the 2.5 NA.  

[Ex Member]

36 minutes ago, deep said:

and even normally aspirated 2.5 diesels.

From idle until when the turbo produces boost, the torque is almost identical to the 2.5 NA.  

[Shackleton]

That was the most pop up ads, moving pictures and computer overheat inducing peripheral balls I've ever seen on a website.

That said I've two Td5's. If I'd any money I'd have more.

[Eightpot]

A td5 is ok, but I wouldn't take one out in the bush unsupported- or without a nagging worry. Tdi is far safer, and if you're not in a rush a n/a is even safer.  But best engine I ever had in a Land Rover was an Isuzu.

[Shackleton]

Funny my second one is in an ex-Aussie overland D2. 

[Snagger]

15 hours ago, Red90 said:

From idle until when the turbo produces boost, the torque is almost identical to the 2.5 NA.  

I don't know if it's true, but I heard claims that the 12J has more torque at low rpm than the Tdi as you don't get the breathing restrictions of an idle turbocharger and the compression ratio of a Tdi is less (19:1 as opposed to 23:1 if I recall the correct figures).  It sounds plausible, though the direct injection and higher injection pressures may offset those factors.

[Ex Member]

5 hours ago, Snagger said:

I don't know if it's true, but I heard claims that the 12J has more torque at low rpm than the Tdi.

It doesn't.  Driven both extensively back to back.

[FridgeFreezer]

3 hours ago, Red90 said:

It doesn't.  Driven both extensively back to back.

Oh well that proves it then!

[deep]

On 3/10/2019 at 6:57 AM, Red90 said:

From idle until when the turbo produces boost, the torque is almost identical to the 2.5 NA.  

And yet, when the Tdi loses revs and goes off steam, the engine goes clunk, while the 18J (presumably 12J is the same) goes chug chug chuuuug....

[deep]

9 hours ago, Snagger said:

I don't know if it's true, but I heard claims that the 12J has more torque at low rpm than the Tdi as you don't get the breathing restrictions of an idle turbocharger and the compression ratio of a Tdi is less (19:1 as opposed to 23:1 if I recall the correct figures).  It sounds plausible, though the direct injection and higher injection pressures may offset those factors.

The graphs suggest the 12J produces more torque under 1,400 r.p.m. than all the other Land Rover diesels.

[FridgeFreezer]

20 hours ago, deep said:

The graphs suggest the 12J produces more torque under 1,400 r.p.m. than all the other Land Rover diesels.

Oooo share the graphs, I like a good dyno plot

[Daan]

[FridgeFreezer]

I've been collecting...

 

 

 

 

 

 

Let the bun-fight commence

 

[Anderzander]

Anyone one for the 12J or 200TDI?

[FridgeFreezer]

2 hours ago, Anderzander said:

Anyone one for the 12J or 200TDI?

I've not found one yet but would happily add to the collection - I find the torque curves informative even if you can't really rely on the numbers up the sides.

Maybe we should have a forum dyno day?

[Ex Member]

On 3/10/2019 at 12:11 PM, deep said:

And yet, when the Tdi loses revs and goes off steam, the engine goes clunk, while the 18J (presumably 12J is the same) goes chug chug chuuuug....

Your TDI is not adjusted correctly.  Seriously...  Her in the land that Land Rover forgot, everyone that has a Defender has either a 2.5NA or a 200TDI.  I've done many swaps and driven the trucks before and after and every trip has trucks with the two engines.  The pre-boost torque is the same.  It just feels less, because when the boost kicks in, you get so much more.

[Bowie69]

Take the RPI graph with a large bucket of salt on the side

[Shackleton]

4 hours ago, FridgeFreezer said:

 

I've never really read a dyno readout before but does this one say the Td5 was taken to 7000+ rpm?

[Ex Member]

51 minutes ago, Shackleton said:

 

I've never really read a dyno readout before but does this one say the Td5 was taken to 7000+ rpm?

No.  That is the force at the wheel (for the torque curve).  It is wheel force, power and speed.  Not adjusted back to the engine.

[FridgeFreezer]

16 hours ago, Shackleton said:

I've never really read a dyno readout before but does this one say the Td5 was taken to 7000+ rpm?

No - bizarrely the X axis is speed in KPH. The little collection shows the massive variability in plots and units of measurement used for each axis.

@Bowie69 - yes you've got to take all dyno plots with a massive dose of salt as they're very subject to hundreds of variables and losses "on-the-day", the useful thing about them is more the shape of the curves. A nice wide & flat torque curve from idle is IMHO the "ideal" for a 2-ton cube on wheels even if it means the peak HP numbers are a lot lower than they could be if tuned differently.

Who remembers the Top Gear review of the Mitubishi Evo where the 400hp version was out-run by a diesel Fiat Multipla until the turbos came on boost?   whereas the 300hp version was far better to drive but didn't have the bragging rights down the pub.

[deep]

On 3/12/2019 at 7:50 AM, Red90 said:

Your TDI is not adjusted correctly.  Seriously...  Her in the land that Land Rover forgot, everyone that has a Defender has either a 2.5NA or a 200TDI.  I've done many swaps and driven the trucks before and after and every trip has trucks with the two engines.  The pre-boost torque is the same.  It just feels less, because when the boost kicks in, you get so much more.

Yes and no.  Whenever you are in a situation where the revs drop, you drop off the torque curve more suddenly in the Tdi.  Because you have more grunt at higher revs, it's likely you were in a higher gear, so you absolutely feel it.  I learnt how this works one day when I led a trip through some dune country.  At one stage, there was a soft climb with a short approach.  I popped up easily in my old Series 3 petrol but the bloke behind me tried and tried and tried with his 200Tdi.  The problem was, if he got speed up in a higher gear, the engine died half way up as the torque vanished.  If he held a lower gear, he didn't have enough speed.  An auto might have helped, of course!  But the petrol Land Rovers had no problem, rev the heart out at the bottom and just let the revs drop as you climb.  No problem.  And I'm very sure my 18J is doing much better at a few hundred r.p.m. too, though you will struggle to build up speed to start with...

[Retroanaconda]

I experienced this in Marquenterre last year, the sand was very dry and deep so pretty bad at sapping power. I was finding that the 200Tdi could not pull through up some of the hills as it dropped off revs and I lost the torque. Others with more powerful engines had fewer problems. I found that for some hills I was having to hit them so hard in order to avoid this (by starting at a higher revs) that I was at risk of damage to the vehicle.

I found a similar issue in the Yorkshire Dales a few weeks back - there were a few hills that fell into that “too fast for third, too slow for fourth” patch which is a bit of a pain. Fair enough I am sure mine has lost some of its horses over the years, but it’s a characteristic of the engine that you learn to drive around. There’s still plenty of torque and it’s low down the rev range compared to many cars as you’d expect for a Land Rover.

[Ex Member]

If you had a 2.5NA in those situations, you would not have made it at all.

[Arjan]

I know 2.5 N/A diesel bashing is a popular thing but they are actually quite good engine is looked after and it has taken me to several mountain tops in the 10,000 feet region......

One just has to accept is takes longer...