Thread: Eny meny miney mo which diesel motors the go

Originally Posted by garryseries3

Just thought I would hyjack this thread a little, are there any inherent problems with Isuzu's in Land rovers either the turbo or non turbo forms. I am lead to believe that unless you have a LT95 with tapered bearings all the rest of the boxes fail behind a turboed isuzu. But apart from that are there issues one should be aware of if you decide to drop one into a landy engine bay.

Can a larger intercooler on it own give a 300tdi more grunt without sacrificing longevity, I suppose I am trying to glean can one improve a 300 tdi performance without fueling it up and add longevity to the motor ie does blue printing the motor help.
Garry

There was a thread on outerlimits about replacing the compressor with a modern high flow unit,$600 including reco of the unit itself,I'm getting mine done when it dies and the outcome was impressive,same boost pressure etc just more air so more go.You can safely harden the tune on your Tdi,it's the people that go overboard that have problems. Pat

Garry hard to hijack your own thread

Originally Posted by THE BOOGER

Garry hard to hijack your own thread

Yes I know, trying to attain a bit more humour in the thread to keep a balance.

I don't think the taper roller is a must, i know of a few getting around (isuzu powered) without it and still going fine..
To make your mind up, drive a 300tdi back to back with an turboed, intercooled 3.9 isuzu.
Not to sound rude , but basically one is a toy diesel and the other is a real one. I have a 300tdi disco ant my place aswell as a non turbo isuzu, i much prefer driving the isuzu. Prior to that i had a rangie with a 6.5 chev diesel, and i still prefer the isuzu, especially in turbo/intercooled form

Originally Posted by uninformed

you say this like there is some inherent problems with the Isuzu crank. Is there? be good to know. I haven't heard of any failures...

I say this as in

"if you are numpty enough to hydraulic your engine so long as you dont bend the crank so badly that it twists a crank main journal or crack the block you can rebuild it"

That Im aware of the only problems that exist with the crank are caused by bad machining or manufacture typically it turns up as a balance problem that makes the engine shake like mad at some points in the rev band and I should point out that the only time I ever saw a crank in that condition was as a demo "this is what you should avoid" when I was learning to build that particualar engine.

Originally Posted by uninformed

ok i understand where you are comming from. But you say per hp, how much hp does the series produce? how much does the tdi produce? im talking about total heat output, not per hp. Remmeber according to you they are the same block... so lets look at heat comming from each engine. i think the argument, that i have said time and time again is output per cubic capacity...

Ok clearly you dont understand WAG... thats a Wild Assed Guess...
guess we need to do a little math then....


google puts the best output of a series diesel at 62 hp or there abouts.
and the TDI300 at 111.

lets make the math easy(ish) and work on 60hp and 110 hp....

60hp calcualtes out at about 161071.1456Kj of energy.
110hp calculates out at about 295296.4549Kj.

now we need to look at just how effecient each engine is. A perfect diesel engine is about 55% effecient but to date the BEST diesel engine ever put together only made a paltry 51% thermal effeciency at its peak economy setting.(reported as being between 50+54% depending on which particular website you want to believe)

lets just say that the tdi is in the order of 35% effecient and the series diesel is about 32% (representing a nice average thermal effeciency number for the era of the engines in question) bearing in mind that thats going to be the best case scenario for both engines ( thats about an 10% difference between the 2 which represents the change in overall fuel effeciency of the 2 engines based on the converted gal/hr/hp numbers for the 2 engines).

crunching the maths the total energy conversion (assuming no additional entropic losses of the fuels energy) that occours in the series is 503346.875 Kj 32% of that gets to the wheels (well the flywheel anyway) so 68% of that is waste heat that the cooling system gets to deal with which works out at 342275Kj.

the same maths applied to the TDI gives.
843704Kj total
548406kj waste heat

Be generous and assume that 50% of the waste heat goes out the exhaust pipe

I'll now leave it to you to work out the enthalpy of the cooling system and work out which has got the better cooling system and what the engines operating temperature is going to be based on that. Bare in mind that these figures are for an engine that operating at maximum power output over an hour.

Originally Posted by uninformed

why is the Defender more open to air flow than a series? Go open a bonnet on a defender and then a series, if you cant see a big difference in "air" around the 2, you need your eyes checked...

clearly youve never put a series front grill along side a defender front grill.


now I apologise for scale but if you cant see that the panel for the series is a touch more blocked by solid metal than the more or less open one for the deefer then I should just stop now.

yes you have a condenser in front of the radiator but at the end of the day they are something like 80%+ airgap anyway.

Originally Posted by uninformed

so my a/c condensor, that your series doesn't have, wont restrict air flow to my rad and intercooler, plus the fact that the rad is pushed hard over to one side...oh and for air to go through the rad it has to come out the back side, into the engine bay. But, as the engine bay in a defender tends to not flow so well the air has a harder time moving through the rad...

yes it will have an effect but the restriction to airflow is significantly less that the solid panels of steel that are in the way of the airflow in the series (see the above picture) and I bet the butterflys dont help the series either.

But at this stage I'm almost willing to bet that you also count on the fact that the 7 blade plastic inch+larger diameter fan with the tighter fitting cowling (when compared to the 4 blade steel fan and the rather loose fit of the series cowling) does nothing to increase the airflow through your radiator but instead simply draws more power off of the crankshaft meaning the engine needs to make more heat to achive a given flywheel power output

as for the fact that the radiator is pushed over to one side whats your point? theres this thing called a cowling that ducts the airflow almost evenly across the whole face of both the radiator and the intercooler.

Originally Posted by uninformed

ill take your word, but id like to see some measurements on the 2, only going from my memory, i would have thought the series the thicker of the 2....its a moot point any way, as isnt a larger frontal surface area a better design, as the air moves across the rad its heating...And again i come back to the fact that its not moving through the tdi rad as good as a series.

IF you count no other design considerations such as cross flow radiators(left to right) and reflow (left to right, down right to left) you would be right a larger faced and thinner radiator would be better than a squat fat jobbie for a lower airspeed application .

it doesnt matter how thick the radiator is, so long as when the air exits out of the back end of the radiator its 1 degree cooler than the coolant the air will still be absorbing heat from the coolant, the second law of thermodynamics takes care of that.

the short version of it is that its the overall surface area of a radiator that counts at the end of the day and not the dimensions. Once youve got a surface area you need to work out an air speed that will permit the best temperature gradient for heat transfer. thin radiators like slow airspeed and thicker ones faster.

Originally Posted by uninformed

umm, why didnt you say this in the begining of this post where you basicly say the series is hotter...clever way to argue a point

because I had assumed that the bit where I wrote "the series donk makes more heat per hp" would have allowed that assumption to be made given that (as alluded to further up there) the series diesel is only good for about half the power of the tdi and that clarifying it with "Id say that the series will push out something like 10-15% more heat while doing the same amount of work" would have further implied that if you ever managed to get the series to make the same power as the TDI (which you cant because the injector pump wont push that much fuel and if it could the injectors wouldn't deliver it and if you changed both you'd then blow the pre combustion chamber out of the head for it to become intimate friends with your piston crown, bore and valves but if you managed to over come all of that you'd never get enough air into it to make the fuel burn completely) it would still be the hotter of the 2 engines.

(if you like you can also track down the thread where I had the top tank temp of fozzy out past 135, Id call that the hotter of the 2 engines)

Originally Posted by uninformed

hint, hint...

well thats a little vague, what are you hinting at?

Originally Posted by uninformed

hahaha what the hell has that got to do with anything....Warrenties in alot of cases arn't worth the paper they are written on, changing the radio station voids the warrenty. Then on top of that you have to throw the dealer into the mix and how they interpret things...My dealer told me that LR no longer made Def 90's in 2000, and his knowledge of the vehicle was less than mine...If thats your argument for not doing mods to any vehicle you really show that you clutching on strong to your beliefs...put a maxidrive diff lock in a LR and you void your warrenty...oh but i bet you'll say thats a bad thing to do...as LR's are perfect to begin with

its got to do with MODIFYing the engine, If you change something then it is no longer functioning as designed. theres plenty of mods you can do the the landy that are worth doing but what you cant do is complain about something youve modified breaking something else say for instance making a cooling system designed to deal with the heat load of a 110 HP engine deal with the heat load of a 135+ hp engine and then wondering why your head/gasket gave way.

The hypothetical question was intended to highlight the fact that if you do something to move the vehicle away from its designed limitations then bad things happen and that if they do then you are on your own.

Originally Posted by uninformed

es to a point. Small increases can be delt with if applied correctly, notice i changed the exhaust which allowed the turbo to work a bit more efficently, i installed a more efficent intercooler, that would provide a little improvemnt in the air, and i increased the fuel to compliment the 2...The EGT's were taken at stock before anything was touched, then the exhaust guys and my mechanic worked together to set the pump.....I believe that I have said, as you are, that over fueling in a turbo diesel is NOT good. You can believe that the wonderfull LR engineers can't be improved on... But hang on, wasn't it you that said that vehicles are built to a cost and maybe other factors that results in the end product...

so you put a bigger exhaust on after the turbo, dropping the post turbo pressure putting a bigger pressure differential across the turbo making it spin up earlier and harder making it shift more air. Not a problem thats good the standard configuration of the pump will make use of that, you wont get any more power but you will get a better preforming engine. The bigger intercooler has the same effect increasing air density, did you think to move the waste gate actuator sense port to the back of the intercooler and putting the boost aneroid sensor on the back of the manifold to maximise the benifit of doing both those mods?

so you set your post mod and post tweak EGT's to be the same as the pre mod pre tweak EGTs? well thats a little silly heres why...

Temperature is defined as the intensity of heat in a substance.

if you have 1kg of air and heat it to 650 Degree's centigrade you have expended x amount of energy heating that air

lets assume that your mods allowed you to push twice the mass of air through the engine.

2kg of air heated to 650 degrees centigrade requires that you expend 2x amount of energy.

the temperature is the same but the total amount of heat has doubled.

the question is, where did the extra heat to heat twice the volume of air to the same temperature come from?

oh and if you raised the pressure of the air before heating it then the heat value also goes up.

for the purpose of that question you can also assume that the time required to conduct the heat transfer remains constant (it doesnt because your mods increase your flow rate which in reality ALSO nets you the requirement to raise the supply heat source to effect the transfer)

Still think that upping the fuelings a good idea? hey its your engine.

but yes the landrover engineers can be improved on, thats why the TD5 is so much better than the the TDI, it wasnt made soley by landrover engineers what you cant do is improve on something thats already made by another engineer without re-engineering it, if engineer A designed engine A to have a head that melts at 400 degrees and engineer B mods engine A to run at 450 degrees without changing the head at all whats going to happen to the engine?

If landrover engineers couldnt be improved upon then the diesels that won lemans would have been tdi's and trucks would use landrover engines as oppoesed to Cat, Man, volvo, mack, isuzu and all the other engines, come to think of it the suzi 3.9 would never have been fitted to the countys or the perenties. But improved upon is speculative it depends on what features you value most.

Originally Posted by uninformed

didnt you say ALL diesels struggle in the cold? read what i said, i do let it warm up a little, but i could drive off straight away without any sign of stalling....

no what I said was "if you idled it for 2 minutes waiting for the oil pressure (which you should have had inside of 10 seconds) wouldnt the combustion chamber, piston top and the head have warmed up enough to be near enough to working temp?" and its the temp of the combustion chamber that matters not the ambient temperature. I also said that 4 degrees would be a problem for fozzy. I have no doubt that I too could drive away in fozzy once he'd fired I just couldn't expect full performance for several minutes

but thats a very clever way of implying that someone else said something you'd like to use against them.

I'll choose to ignore the tnaty bit in the middle and adress this bit first.

Originally Posted by uninformed

YOUR OFFICAL STANDARDS... where can i find a copy of these?

you can find my official standards in the following places, assuming you can gain access to them.

DI Pers
DI Admin
DI Log

They are Defense Instructions, Any Defense establisment library will have the full volumes of all 3

AAP which is the Australian Aeronautical Practices documentation which you should be able to obtain from any Aeronautical maintenance depo except for the military ones which you would need to get from a Defence Technical libraries wing.

the TRAM which is the Technical Regulations of Aviation Material Maintenance
EMEI's which are Electrical and mechanical Engineering Instructions

Both again will be in the Defense technical libraries

then there the less important ones

The ADR which you can read online from the department of transport
and all the other less important documentations like the mechanical Engineering guide books Army technical Trade manuals the Diesel fitter and plant maintainers books, several steam engineering compendiums, Rave, Workshop manuals, and a couple bits and pieces I worked out along the way.

and before you ask. yes some of those carry over to driving but on the driving front theres the Transport Regulatory Act, Sovo's DRTI's and a few other lesser documents.

Originally Posted by uninformed

so are you agreeing that EGT's can rise in a stock engine to a point where they can be harmfull, and would be better to drop back to forth?

Not agreeing to that at all. A stock, correctly maintained automotive engine operating in its intended environment will not produce harmful EGT's nor overheat. If you labour such an engine in those conditions it can cause mechanical damage to itself and eventually it will stall. At this point it should be noted that ALL automotive engines have an intended operating range and operating outside of that range is considered to be outside of the intended operational environment. Keeping your engine in the operating environment is just one sign of a mechanically sympathetic operator.

Originally Posted by uninformed

Agreed, but can you agree that others too may know how to do these appropriate tweaks, is it only you

theres plenty of people who know how to do these tweaks in fact any semi decent mechanic with the operating schematic and tolerances of the engine (and logically the injector pump) should be able to work them out. A lot wont tell you about the consequences of your actions and give you the "I did what you wanted done under your explicit instructions" line when you blow something up. They'll probably be a lot more subtle than that and do something like blame the extended kilometers of the engine/previously undetected damage to the engine from the previous owner and then hit you up to do the repair work. Im a lot more vocal on the downside of what can happen and the reasons why it happens and theres a few reasons for that which dont need really to be gotten into here.

The other thing against doing some of the tweakings especially when there is such fine tolerances to be worked with is the potential for mistakes AND the fact that almost no-one does the tweaks in a pump room on a calibrated pump rack so your test bed is your engine, if its badly enough wrong you can kill the engine on the first test run. I'm lucky I get all my technical measuring gear calibrated every 3 months or so but even then I have off days.

Imagine what would happen to an inline FIP that was ment to have a bump clearance of .1mm set at 25 degrees after flushing the pump with shellite injector test fluid and the mechanic that set it for you did so with it primed with diesel on the engine, on a cold morning (lets say less than 10 degrees) and his depth gauge was reading over by .04mm

Originally Posted by uninformed

ill agree the fan probably flows more air....on paper or in a test lab, but not real world useage

your welcome to test that, see if you can get a cheap Kmart towel to stay up on the front grill of a series and then try it again on the tdi, do the test at about 17-1800 Rpm which from memory is where the fan delivering maximum air flow.

Originally Posted by uninformed

do i fall into that category

possabley, are you admitting to killing a TDi after it was tweaked on the pump, are you upset about this fact? do you think that its a fault of the engine itself or the people who designed it?

Originally Posted by uninformed

how often do you tow 1.8tonne with a series? mon-fri? how do you feel about the performance from a safety asspect when using the same roads as people that drive modern cars, being able to move off at a reasonable pace, merge onto a highway with safety, maintain safe speeds up inclines, overtake etc....don't interpret this as i want to go fast, im talking about legal speed limits...

I tow that about once a month or so, The performance is fine, driver anticipation and time and route selection play an important part of that, its part of operating a vehicle. once you assess the risks and take the appropriate actions to mitigate the risks you can do the run as safely or as riskily as you're comfortable.

Originally Posted by uninformed

interested to hear more about your 3tonne steerable trailer. whats the specs on that? how does it steer? maybe start another thread about it.

nothing special the military styled mobile refrigerators for the cooks steering was via the draw bar, Im not sure I have any pics but a couple of the F111 powercarts use the same mechanical setup. If we get one come out of the no photos area I'll see about getting some.

if you look at the front end setup of a series , attach a draw bar to the center of the axle housing and then pin pivot the draw bar on the tie rod then youve got the right idea.

Originally Posted by uninformed

umm putting your series into low range on the road is not advised by the manufacture...transmission wind up. oh but you may only drive on level ground in a straight line.... for defenders, starting at lights and having to use low range is possible, but not ideal as when you have to change into high range, using the LR procedure, the weight of the trailer can play havic, and i like my transfer case and the gears inside it. dont really want to wreck them...

Actually the manual says Prolonged driving in low range on bitumen roads may result in increased tyre wear, (this varies from one manual edition to another) but as its a fairly large cut tcase and its a non constant mesh gear change its very easy to just get it creeping and then shuffle hi range in a series.

if you have to do that you stay in low range till you find somewhere where you can stop and move off in high range, anticipating the lights and traffic conditions is generally the best method.

and Finally someone else who thinks that way about doing the lo-hi shuffle.

Originally Posted by uninformed

a question for you, do you feel the track rod and drag link are over engineered? do you feel the diff centers, axles, cvs are over engineerd? do you think it was a case of over engineering when LR made the wheel bearings closer together in the hubs? or removed the little steel washer that was welded to the rear trailing arm ears (axle end) that made them stiffer? or made the vents out of thinner alloy? or changed the sals rear to a p38 in 110's and 130's...

Nope they arent supposed to be, the drag link and track rod are intentionally weak so that you dont kill the steering box, the steering arms or the pitman arm if it all goes bad.

having only ever broken 1 diff and a gearbox (in an overpowered v8 disco 1 whilst being stupid) and 3 axles in a series that I didnt know had a bent axle housing near the diff I have no problems with the engineering standards. They could be stronger (and theres plenty of after market ones that are) . I don't personally think that shortening the bearing space was a good idea but I understand why it was done and yes even with the smaller bearing space I think that the stub setup is still over-engineered for its intended purpose. They didnt just change the spacing at the same time as the bearing spacing was changed so was the setup procedure. Removing the steel washer was a cost saving effect and Lo EMEI's say to put it back.

Originally Posted by Blknight.aus

the stalling while cold still applies to modern diesels the concept is the same but you get more assistance from your electronic control to stop it it still happens tho.

well you did say it here, and my 300tdi didnt have electronic control either. If i started it up and drove off immediately, it would not stall.....

but other than that, i think Dave just handed my arse to me. its clear he has way more knowledge and understanding about this stuff than i do. not hard really.

i guess what ****es me off, when people start making assumptions about things they don't have facts on....like the mods on my engine, its condition, how it was serviced and how i treated it day to day...

i tried to state some facts that i have delt with in real life situatiuons. using the defender as a work vehicle LIKE IT IS MARKETED AS. Regarding Pat, i only figured out he has a disco, not a Defender so i can't comment on that particular vehicle, never owning one. Gary started this thread and he was asking about working Defenders.

Dave, you seem to be a great asset to this site, but i think you could take your blinkers off once in a while. Nothing wrong with being loyal or passionate about a brand, but when it fogs your perspective it becomes pointless. You talk about all these documnets i can go read to make sure im looking after my Defender properly....WHY WERE THEY NOT INCLUDED WITH THE VEHICLE FORM NEW? you may be spot on and thats what they need. BUT, do you think that a vehicle owner should have to become a automotive expert or research to the point you are talking, to achive a acceptable service life from there vehicle. its a bit hard to here you say that the engines are over engineered, and then say we have to meet all these strict requirements to get a reasonable service life out of them...

LIKE I KEEP SAYING: i only used my vehicle within the manufactures specs. i had it service to manufactures specs, i drove it accordingly to the fact i was towing a largeish trailer.

yes i did have my truck modded, do i think it was doing it in a bad way, NO... i went off the info i had gained about the place, but it doesnt matter how much one reads, you will always find someone who knows more after the fact.

i really dont think its good that i should take off in low, find a spot to pull over and then select high...i think thats the vehicle not performing to a realistic standard. but i do understand why you said it and it would be the most mechanicaly sympethetic way...although even in 5th low you wouldn't be traveling very fast to keep the EGT's down....

do you do services and mods? maybe we should all bring our trucks to you for peace of mind.

i still think you are wrong about egt's getting high when climbing in 5th gear and dropping back to 4th, ive seen it on my egt gauge...i wish someone would back me on this or explain it better than i can. BUT i didnt destroy the engine in 5th to find out...

regarding the track rods and drag links, etc....come on man you have to be kidding, my track rod was bent, this is running stock size tyres and doing very little light offroad. i agree about it being the safe weak link, but you are kidding yourself if you think they are good enough on a stock vehicle in stock conditions...your starting to sound like the LR engineers that would have nothing of the feedback the Australian army was giving them. they just simply would not believe what was infront of there eyes.

im sure you will come back at this again, and make me look dumb again.....or did i do that all by myself.

Point is: Gary asked a question. i gave him facts from my experience doing what he will be doing, using a Defender for work. they have good aspects, they have bad. now after reading everything, especially the info from Dave, that shows how critical you have to be with servicing to the point that you need to resarch extra information, that the mods that can be done have a paper thin tolerence, and that you must expect to be the one holding up traffic and predetermining every route when loaded(to bad if life gets in the way and things come up....) then you know what to expect to get the safe performance out of your 300tdi.... Gary i wish you the best of luck and seriously hope you or anyone else does not have the same experience i had...

do as much research as you can, speak to the izusu guys, speak to dave about the 300tdi....

if you dont have a bullbar or anything else in the way, i would look at, no matter what engine, a full width rad and full width intercooler... also a 3 inch mandrel bent exhaust...

Serg

Originally Posted by Blknight.aus

I say this as in


so you put a bigger exhaust on after the turbo, dropping the post turbo pressure putting a bigger pressure differential across the turbo making it spin up earlier and harder making it shift more air. Not a problem thats good the standard configuration of the pump will make use of that, you wont get any more power but you will get a better preforming engine. The bigger intercooler has the same effect increasing air density,

Well I am curious the Tdi can it be improved can it be made to last longer by tweaking with some aspects of the motor/ancillaries and its design. In simple terms what can be done to enhance its reliability. efficentcy and tractability.
Garry

Mate you have taking what I have written the wrong way,you have used your defender and only your defender for your work,you must realise that I have used just about all types of vehicles and they all fall to pieces.As regards to vehicles used in that way they will get more wear,and don't confuse wear with under engineered in a year than most privare vehicles get in three.I replace door handles,switch gear,nobs,buttons,mirrors,seats on an everyday basis and not just LV's but site machinery also and take what clowns say about reliability with a grain of salt as they are reliable but only because people like me throw parts at them hand over fist.What Dave said about the steering is correct,you always make the cheapest easiest to fix part the weak link,that is sound engineering. Pat