Running a 300tdi without an intercooler

[ToyRoverlander]

Nope, didn't measure anything. I'm not interested in actual inlet temps, I'm more interested in exhaust gas temperatures.. When there's hardly any heat put into the compressed air (low boost, low load on the engine) there's not much point trying to cool it down. When there's lots of boost and thus the inlet air does get warmed up a lot, that's when an intercooler comes into play to cool that air as much as possible.

[Ally V8]

I disagree, if you read this (my own findings), you will see why: http://forums.lr4x4.com/index.php?showtopic=78688&page=1

I would not run a tdi without an intercooler myself, it is a free mod in terms of gains, even if you dont use the extra power, it will translate in better efficiency. You will need to use a fan with it at low speeds though.

Daan

Interesting stuff,but for my use it isnt worth bothering,the 2 1/4 petrol I ran for the last 20years had enough power to do the job.The job is pulling dead elm trees that are rarely more than 400mm thick at the base,towing a 750kg trailer with firewood and dragging dead LR's in and out of my workshop.(Yard is steep)

So the 200 TDI will have an easy life,rarely go more than to the village,( 3 miles ) to fill with fuel or for MOT etc. And thinking back my Fathers 1987 90TD lasted many years and did alot of hard work with no problems - that managed with no intercooler...

[dave88sw]

I've been running a 300Di for 5 years now with which overall I'm very pleased with it, as a daily driver she's perfect. If there is one let down it would be when I'm climbing a tricky spot where some wheel spin would help, I just can't get enough rev's to break the tires loose. With a turbo I'm sure that I could.

So with that last sentence said, I've been thinking of upgrading the motor with installing a turbo again but without the inter cooler. (Fingers crossed that the MOT man doesn't notice it) Dave, will you be running the external oil cooler? In my original conversion I deleted it but with already buying a turbo I ordered an universal oil cooler that I will place in front of the radiator. The 300tdi's normally run cool plus the oil cooler is thermostat controlled, so even if the motor oil does get hot, the oil cooler thermostat will open helping to lower the motor temp.

With what I've read on the internet which was sparse, I think that running without an inter cooler you will be ok. As long as you look out for heating issues with a low restrictive exhaust, a good radiator and an external oil cooler.

Todd.

I'll be using a Discovery radiator so will have the standard oil to coolant cooler. However, i have used a remote filter housing in my conversion so have lost the oil thermostat. I can't see that the lack of thermostat will be an issue as it's plumbed: feed-filter-cooler-return and therefore could only run a bit cold as the only issue.

I enjoyed reading your 300di conversion thread, i was impressed with how neatly done it was. I'm still unsure about the intercooler issue though, i suppose as it will likely see a bit of motorway use, i ought to put the effort into fitting the intercooler as prolonged use with the turbo spooling is probably the worst for raising EGTs.

Cheers

Dave

[Green Bob]

I've been running a 300tdi in my 90 since about September 2011 without an intercooler, simply due to a mixture of laziness and lack of time. In that time, I've probably done about 50k, more recently around 400 miles a week on motorway at 70/80ish and the only issues I'd put down to a lack of intercooler is black smoking and possibly worse mpg: 20ish.

So I'd say you'd probably get away with it without one.

I intend to put an intercooler in (there's one sat in the garage) but mainly so I can get better fuel efficiency and maybe play with the fueling a bit without melting pistons..

[Landowner]

An intercooled 300 pulling a heavy trailer up a very steep incline at say 10mph on a hot day would have little or no advantage over a non intercooled 300 doing the same.

Intercooler is only of any use when cold air is being rammed through it to cool the air coming from the turbo.

Loss of power from split pipe is down to lack of boost and not cooling.

I dont think the intercooler is much use at all unless the engine is working and the vehicle is travelling enough to ram the air through the intercooler, outside air passing through the vanes would be travelling much much more slowly than the air being rammed though by the turbo

Just my thoughts and not anything scientific,

[Daan]

An intercooled 300 pulling a heavy trailer up a very steep incline at say 10mph on a hot day would have little or no advantage over a non intercooled 300 doing the same.

Intercooler is only of any use when cold air is being rammed through it to cool the air coming from the turbo.

Loss of power from split pipe is down to lack of boost and not cooling.

I dont think the intercooler is much use at all unless the engine is working and the vehicle is travelling enough to ram the air through the intercooler, outside air passing through the vanes would be travelling much much more slowly than the air being rammed though by the turbo

Just my thoughts and not anything scientific,

This is exactly what I was describing why you need to have a fan at low speeds. A good working viscous fan with the correct cowling that is properly sealed to the rad and intercooler. Without it, the intercooler is pointless at low speeds.

Daan

[Landowner]

This is exactly what I was describing why you need to have a fan at low speeds. A good working viscous fan with the correct cowling that is properly sealed to the rad and intercooler. Without it, the intercooler is pointless at low speeds.

Daan

So it wont melt yer engine without an intercooler then

[ToyRoverlander]

At low speed in low range there's usually hardly a load on the engine anyway, thus not much boost, thus no need for an intercooler thus no need for a fan

Intercoolers are of interest when there's lots of boost, to cool all that air back down as much as possible to keep EGT's in control.

[Landowner]

At low speed in low range there's usually hardly a load on the engine anyway, thus not much boost, thus no need for an intercooler thus no need for a fan

Intercoolers are of interest when there's lots of boost, to cool all that air back down as much as possible to keep EGT's in control.

I remember a couple of years ago pulling up the hill from Saltburn beach with a Fordson dexta on a trailer. All up weight was about four and a half tons and the 200tdi Disco was boosting all the way up even though revs were quite low and speed was about 10mph, that hill is at least 1 in ten maybe steeper with two hairpin bends on the way up, no way was the air boosting through the intercooler getting cooled

[muddy]

An intercooled 300 pulling a heavy trailer up a very steep incline at say 10mph on a hot day would have little or no advantage over a non intercooled 300 doing the same.

Intercooler is only of any use when cold air is being rammed through it to cool the air coming from the turbo.

Loss of power from split pipe is down to lack of boost and not cooling.

I dont think the intercooler is much use at all unless the engine is working and the vehicle is travelling enough to ram the air through the intercooler, outside air passing through the vanes would be travelling much much more slowly than the air being rammed though by the turbo

Just my thoughts and not anything scientific,

This is why it has the fan. People who fit an electric fan often forget about this. If your struggling with a heavy trailer up a steep incline you want as much power as possible.....

If you really can't fit the inter cooler I don't think the world will end, however if you can then I would, even a shagged old 21/4 can knacker the transmission if your foot decides so. It was fitted for a reason the chaps and chappeses at landrover aren't daft.

Will.

[Landowner]

This is why it has the fan. People who fit an electric fan often forget about this. If your struggling with a heavy trailer up a steep incline you want as much power as possible.....

If you really can't fit the inter cooler I don't think the world will end, however if you can then I would, even a shagged old 21/4 can knacker the transmission if your foot decides so. It was fitted for a reason the chaps and chappeses at landrover aren't daft.

Will.

I wasn't struggling up the hill, the Disco was pulling nicely in first gear at about two thousand revs on about half throttle, wouldn't have taken second and no point in revving the nuts off it, wouldn't have noticed extra power from intercooled air as it wouldn't have been that much.

I doubt if the intercooler adds that much more power under normal urban driving anyway

[Green Bob]

I remember a couple of years ago pulling up the hill from Saltburn beach with a Fordson dexta on a trailer. All up weight was about four and a half tons and the 200tdi Disco was boosting all the way up even though revs were quite low and speed was about 10mph, that hill is at least 1 in ten maybe steeper with two hairpin bends on the way up, no way was the air boosting through the intercooler getting cooled

It's around 1 in 4...

No half measures in the north east.

[oneandtwo]

I fitted the intercooler in my series 2 with a 200tdi/300tdi hybrid and there's far less room than in a series 3

[Landowner]

It's around 1 in 4...

No half measures in the north east.

Thought it was steep, glad the tractor was strapped on well, Disco pulled up it no problem with no fan so no intercooling

[ToyRoverlander]

For very short periods an IC works as a heat sink, still cooling the inlet air temp even if there is little airflow. When speed picks up the IC will be cooled down again by the airflow.

[Mo Murphy]

That's a tidy job, oneandtwo.

Mo

[Lewis]

That's a tidy job, oneandtwo.

Mo

Agreed, looks factory-esque. Good work!

[Snagger]

Daan and Koos are absolutely right that an intercooler with no airflow, ie one with the fan and/or shroud removed and low vehicle speed, is doing little.

As for its effect on EGT, I doubt it'd be much - for what inlet temperature drop it gives, it probably loses by adiabatic rise during compression of the denser air charge. I have no way of measuring or calculating any of that, but I suspect the effects are minimal.

[Boydie]

Gentlemen (and Ladies) I think you are missing the point here. Okay the ideal stoichimetyric fuel/air ratio for petrol engines is 14.64 : 1 (lambda=1) for diesels the equasion is far more complex as they run leaner at ratios of 18 : 1 and greater up to 80 : 1, they also require compressed air heated to incredible temperatures by the piston to ignite the diesel fuel.

Now, diesel being a slower combustable than petrol the engine the piston speed is naturally slower, this makes the induction of the large volume of air required a problem, given the static resistances that the induced air has to travel through intake pipes, filters and manifolds, therefore one fairly easy solution for engine designers was to fit a turbocharger.

This little device as you know pumps the combustion air into the engine to overcome the inefficiencies of normal induction. This however gives rise to a duel edged problem. Firstly air, when compressed becomes heated, this compressed and heated air originates from a superheated turbocharger so its volume is vastly increased, therefore instead of pumping into the combustion chambers more air than a normal induction engine could achieve what you have is a volume of super heated air that due to its huge volumetric increase is only marginally greater than you may have achieved with an otherwise efficient NA engine.

The requirement therfore is to cool the air down and in doing so rapidly reduce its volume so the final volume of air entering the engine combustion chambers is far greater than could ne possibly achieved otherwise with a NA engine.

This method/device of cooling the combustion air down is called and Intercooler. The most efficient intercoolers are water to air intercoolers, air to air while being simpler are not so much so. Either way if you dont install one you are not utilising your turbocharger to its maximum effect.

[ToyRoverlander]

It's actually called a charge cooler . Anyway, the most effiecient are front mounted large and thin air to air coolers, not water to air. Greater surface area, greater temp difference less efficiency loss (first having to heat up water which has only a certain percentage efficiency, then that water has to be cooled by air at again less than 100% efficiency).

What exactly are we missing? All the things you say are things that were already discussed. Piston speed is not neccesarily lower, depends on the engine. OM606 easily revs to 5000 with no problem whatsoever. And old perkins 4.236 doesn't go much over 2800rpm afaik.

The turbo vastly improves driveability and power in a diesel, and lets not forget vastly improves high altitude performance. AFR's in a diesel indeed do vary a lot, but do get important under load. That's where you can play with boost pressure and/or a more efficient IC to increase AFR to lower EGT's.

Depending on boost levels an IC might not be needed. As long as EGT's are good there's not a single issue with not running an IC.

[Landowner]

A lot of technical stuff being spouted here I must say

In the fifties and sixties there were very few diesel engines with a turbo charger in fact very few engines at all.

The trucks of the late sixties with big diesels managed without one but they were getting bigger and expensive to run.

European imports had a smaller engine with a turbo and slowly this idea was accepted and Rolls Royce, Leyland and Cummins soon followed with turbo motors, power was up and economy also better but no intercoolers yet. Gardner diesels did use a turbo on a 180 hp motor and took it up to 200 with hardly any blow at all and it was useless because they geared it up to be low revving at 60mph and ruined the pulling power.

Other manufacturers also available at the time (disclaimer) Just talking about the big engines here, during the eighties trucks were still ungoverned and we were cruising the motorways at 65 to 100 mph, I had a truck running at 38 tons which would top 100mph (103) according to the rolling road man at Foden Sandbach, the tacho would go back to zero after 85mph and not re engage until the truck stopped and the needle relocated. Not much would catch it needless to say.

Big Intercoolers arrived on large trucks somewhere in the late eighties as far as I can remember because of the need for lots of power. The reason power was needed was for economy, trucks were governed to 60mph ish and geared up so that they were low revving at that speed, less engine revolutions = less fuel being used.

The intercoolers are massive and in front of the radiator, cooler air is more dense and so the cylinders are better filled and bigger bang, I would like to know how much more power an intercooler provides on a land rover engine, perhaps some one could blank theirs off and report back.

[Ally V8]

I think Snagger is spot on with his comment about about the value of an IC with respect to EGT's. Further to that,the impression given that a turbo without an IC is a waste of time or possibly detrimental to an engine is way off. Literally millions of diesel engines are in use worldwide with forced induction,but no charge cooling.

Companies like Perkins are still selling new units that are available in N/A,turbo or turbo/intercooled versions with varying outputs depending on the OEM's requirements.

Kohler diesel, (Lombardini ) have only recently brought out an intercooled engine,until now all their turbo engines have done without.

I think it would be an interesting visit to go somewhere like Perkins to see their R+D dept,see what test figures they get when speccing the engines they supply.

[Snagger]

Sorry, Boydie, but it's not the turbo/super charging that creates huge adiabatic thermal rises to detonate the fuel as it's injected but the adiabatic rise from the pistons' compression strokes. The forced induction is not primarily to overcome the drag of the induction tract and filter but to compress a large volume of air into a smaller volume, increasing its density very significantly to increase the amount of oxygen, allowing more fuel to be injected and thus simulating a big capacity engine without the mass and external size of such. The thermal rise of the charger is not a big problem, it merely reduces the amount of density gain and can be easily countered by use of an intercooler. You could just run the charger at higher boost to get that desired density, but the higher pressure could cause problems for the structure of the tract and engine. Mainly, though, compressing the air to a higher amount will require more energy, working the charger harder, putting ut under more strain and requiring more energy from the engine to drive it, while the intercooler will give you that density increase with less charger effort, less strain and no extra engine effort (ie, no extra fuel consumption). The intercooler is essentially a free charge, giving performance increase at no cost to the engine longevity or fuel consumption.

So, removing the intercooler will have a slight reduction in performance and will require a turning down of the injection pump's boost system (remember, it sensed the air density by taking its pressure from the turbo's compressor, not the manifold, and is originally calibrated with the intercooler in the system). You could leave the pump alone and put up with a little black smoke under load, or you could turn up the turbo waste gate actuator and turn down the fuel response to get a clean exhaust with the same performance as with the intercooler.

[discomikey]

We do a LOT of cooling runs measuring hundreds of different temperatures with any new projects. A lot of attention is drawn towards the efficiency of the charge air cooler, and whether it meets the engine suppliers designed specifications. The amount of testing done by us in that respect is relatively little (time wise) than that of say JLR's E&D department so i would imagine (because cost IS everything) there is a need for it on these engines, if they could have got away without an intercooler on a 90 200tdi I'm positive they would have.

although they are designed to cope with a large range of situations, and like you say, the efficiency (as a heat exchanger) at low speeds could be questionable but also there.is a fairly.large element of heatsoak, Ali is good for drawing heat away, and the thickish cast "tanks?" on the standard intercooler would be reasonably good at doing that

[Boydie]

Snagger, you missunderstood me, agreed the adiabatic temperature rise is produced by the piston compressing the volume of inducted air within the cylinder by the piston however I'm confused by your claim that this "increases" the quantity of oxygen, this simply isnt true, what percentage of oxygen you have inducted quantity/volume wise wont change unless you run nito (laughing gas) into your induction system, an old mate of mine tried this with incredible results but it was too expensive to consider as a permanent fixture.

And yes, even today some large capacity truck engines still run a turbo induction system without an intercooler/charge cooler but the fact remains that the cooler the inducted air is, the less it has expanded so for a given turbo pressure (in my case with my 300Tdi, 14.7psi) the more actual air is pumped into the cylinder. The few non-IC truck engines I've seen of late (mainly Mercedes Benz)have considerable length of inlet pipes/inlet manifolds and have, in some cases, water - cooled turbos, which contribute to lower inducted air temperatures. I'd also guess the ambient climate would also have a lot to do with the fitment of an IC as well.

On a recent trip we left Melbourne going to Cairns Julie and I went from 15 degrees C in Melbourne (25%RH) to -5 degrees crossing the Snowy Mountains (2%RH) to 45 degrees (85% RH) in Cairns - all during a 48 hour trip.

The most popular heavy truck sold here in Oz is a Western Star, these are a conventional "Bonner Over" rig with massive amounts of space arround the engine for servicce access as well as air flow from the thermally controlled fan. I am reliably informed that 90% of these have 18 litre 8 cylinder Cummins or 12 litre 6 cylinder Detroit motors with Allison or Eaton drive trains and all are fitted with a massive air cooled IC/Charge Cooler. I'd hazard a guess that these are not so essential in cooler climates.