Diesel Vs. Propane Vs. Gas - HDJ81 Vs. Suburban

[aircrew]

Power is mileage when it comes to larger vehicles. The less the engine has to work, or be lagged to get the same results. Restriction is bad, but too much power can start to be wasteful. When it gets to the point that the required power was two or three times lower then what you have then you are just pouring fuel into the engine.
But really to wheel, depending on what you do, doesn't really require all that much power. look at zuks!

 

[Dougal]

Power is mileage when it comes to larger vehicles. The less the engine has to work, or be lagged to get the same results. Restriction is bad, but too much power can start to be wasteful. When it gets to the point that the required power was two or three times lower then what you have then you are just pouring fuel into the engine.
But really to wheel, depending on what you do, doesn't really require all that much power. look at zuks!

Sorry mate, but that's not right.
Engine efficiency, low rolling resistance, good aerodynamics and appropriate gearing are what makes for good fuel economy.

An engine making peak power is working a long way away from it's best efficiency point. Having more power than necessary to do the job usually results it in being used to the detriment of fuel economy.

 

[aircrew]

Ok, so then for instance. A usdm sr20de in a nissan sentra getting 25 mpg versus the turbocharged sr20det getting 34 mpg? the weight of the vehicle being around 2200 pounds. My grand father also told me the same. he was an engineer for deutz, that a generator unit required to make a certain amount of power at a constant rpm would make the same power at a lower rpm with a forced induction system. and lowering the rpm not only made the engine last longer but use less fuel.
And this is a set that is on for weeks at end...
Tell me, how can that same prince pal not be used in this scenario.

And hey can you tell me why diesels are so much more efficient. I mean the fuel being more of an explosion of pressure rather than a slow release or burn in the gas end. and higher pressure, which a turbo also does. maybe they get better mileage because there is more power available and the engine does not have to work as hard!

 

[aircrew]

I agree that excess power is useless. But, up to that point it helps.

 

[Dougal]

Ok, so then for instance. A usdm sr20de in a nissan sentra getting 25 mpg versus the turbocharged sr20det getting 34 mpg? the weight of the vehicle being around 2200 pounds. My grand father also told me the same. he was an engineer for deutz, that a generator unit required to make a certain amount of power at a constant rpm would make the same power at a lower rpm with a forced induction system. and lowering the rpm not only made the engine last longer but use less fuel.
And this is a set that is on for weeks at end...
Tell me, how can that same prince pal not be used in this scenario.

And hey can you tell me why diesels are so much more efficient. I mean the fuel being more of an explosion of pressure rather than a slow release or burn in the gas end. and higher pressure, which a turbo also does. maybe they get better mileage because there is more power available and the engine does not have to work as hard!

Your nissan example is missing a few points. The main one being that turbo petrol engines get worse fuel economy than their non-turbo counterparts.
This is because even the non-turbo one delivers enough power to cruise at it's most efficient rpm without needing boost.
None of the nissan petrols I know of give better fuel economy turbocharged.

What your uncle was getting at is an engine that isn't working at it's best efficiency point because it didn't have enough power.
For example, if you had a small diesel engine that only had enough power to pull 4th gear at 100km/h (say 3000rpm).
If you could turbo it and get enough power to run a higher gear (and say 2500rpm) at 100km/h then you will expect to get better economy.

There are two main reasons why diesels are more efficient. The first is their compression ratio (roughly 16-23:1). Typically double what a petrol engine runs (8-11:1). This lets the pistons get more energy from the expanding gas.
The second reason is the lack of a throttle plate (some toyota diesels are the exception here). The throttle on a petrol engine literally strangles it. Necessary for speed control, but not good for efficiency.

 

[aircrew]

Well then why do I get better efficiency in my truck? mazda b2200 with a swapped sr20det.
Better than the old mazda engine and better than the sr20de I had in there before.

 

[aircrew]

Diesel fuel requires heat and compression to burn. simple

 

[Dougal]

Well then why do I get better efficiency in my truck? mazda b2200 with a swapped sr20det.
Better than the old mazda engine and better than the sr20de I had in there before.

At a guess, your SR20DE had issues. Your SR20DET turbo (T28) doesn't deliver any boost at legal cruising speeds so can't positively influence your cruising fuel economy. The DET engines also have a lower compression ratio, so they are less efficient than the non-turbo DE motors.

The heat to burn diesel is generated within the cylinder by compressing the air. More does not help.
Diesel intercoolers are a well proven concept. Telling me they are a bad idea will not change that.

 

[aircrew]

Nope, t25. same bore and stroke. exact same block and everything. Nothing wrong with the sr20de, actually. a sr20de with a turbo is a sr20det. only difference is that the de has dizzy, where as det has electronic ign.
I starts to produce boost at 1800 rpm. and well in to the 7500 rpm range. I have 7 psi of boost at about 110 km/h.

 

[aircrew]

I think that if you were thinking of getting a diesel. a cruiser would be a nice addition. What about these guys. I have heard good things about them.

www.tyeeimports.com

 

[Dougal]

Nope, t25. same bore and stroke. exact same block and everything. Nothing wrong with the sr20de, actually. a sr20de with a turbo is a sr20det. only difference is that the de has dizzy, where as det has electronic ign.
I starts to produce boost at 1800 rpm. and well in to the 7500 rpm range. I have 7 psi of boost at about 110 km/h.

The SR20DET is a factory turbo engine. It has different pistons and compression ratio to the SR20DE.
The only SR20DET with a factory T25 was from the japanese domestic market Nissan Avenir. Both engines have been produced with electronic ignition.

Do you have a DET or a DE with a turbo bolted to it? They are not the same thing.

 

[aircrew]

Well the sr20de I had, was usdm with distributor. I then added a turbo and eventually sold it to a guy who put it in his fwd sentra. the sr20de is from a usdm sentra. The sr20det I have in there now is jdm, from a silvia. not an avenir.

read sr20det

http://en.wikipedia.org/wiki/Nissan_SR_engine

 

[aircrew]

my comparison of sr20de is stock sr20de with no turbo to stock sr20det with turbo.

 

[LCdreamin]

I think that if you were thinking of getting a diesel. a cruiser would be a nice addition. What about these guys. I have heard good things about them.

www.tyeeimports.com

Yes I've been watching him closely for a while, unfortunately he doesn't seem very keen on giving information. Have to repeatedly send emails to get answers. Although he doesn't seem to hide things like the fact that one might have damage history, but it's hard to find out just what exactly the damage was. Kinda turns me off that I need to hassle him continuesly, although I like the fact that he has a relatively large selection or cheaper trucks.

 

[aircrew]

I like the fact that they are all checked thoroughly. and I too like that they are affordable

I had an easy time getting ahold of him?

 

[aircrew]

they also have a sale on right now.

 

[LCdreamin]

I like the fact that they are all checked thoroughly. and I too like that they are affordable

I had an easy time getting ahold of him?

Interesting, cus everytime I ask something and he says yeah I'll get back to you on it, then never does. Maybe I just have bad luck with these guys. Or maybe my questions scare them away, although I don't think they're overly difficult questions.

 

[crushers]

I was talking about 80 series.
The 70 series you've just bought up is leaf sprung all round.
http://specs.amayama.com/specs-toyota-land-cruiser-1991-august/8695/ But the rest of us are a lot more realistic and secure enough to openly discuss both the positive and negative aspects of our vehicles.

once again you ignore the facts, you are so good at that, if you get proven wrong, ignore it and post some other crap up...

and yes, i will put a 70 up against a 90. or even better i will put the LJ70 up against your 90, coil verses coil, with the same dimensions as above.

the point of this post was to prove that the Land Cruiser is NOT the heavy barge you are claiming (no where did you post up which series you were comparing) and once again you ignore the relevant facts.

your posting was wrong, or are you to proud to admit your mistakes? never mind, over your last 250 post you have never admited wrong just ignored them when pointed out.

 

[crushers]

Now power, fuel economy and emissions are well beyond what was ever acheived before the emissions controls were bought in.

now where are these "facts" coming from? how many of the old late 60s v8s have you actually driven? (never mind, you never back your post with personal real life experiences. )
the old 383 cranked out an underrated 375 hp and would return high 20s fuel milage.
the old 350s cranked out 325 hp with high 20s fuel milage...
this is from personal experience, the newer V8 engines are STILL trying to achieve that milage.
you really need to stick with what you know, Rovers, junk yard turbos and swapped in Nissan diesels... any time you go outside those boundries you end up posting untruths and misleading "facts".

 

[crushers]

Difflocks on landcruisers were never standard. They were an extra cost option which only a small proportion have.

But the rest of us are a lot more realistic and secure enough to openly discuss both the positive and negative aspects of our vehicles.

if an option was a factory installed option it is still stock vehcle. you never said "base" vehicle, you said stock...

as for you being "secure enough" to post up the negative about our vehicles... i must have missed the post where you posted up the shortcomings of your Rover. (or is your truck perfect?)