Most simple diesel engine
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wow, this was an interesting way to kill 30 minutes 
3B, H55, 1984, 2nd owner (first was a lady and I met the head mechanic at the Toyota dealer that always worked on the truck - nothing more then regular maintenance, belts, hoses, oil, etc.)
I got it at 326,000km, lifted it, abused it off-road, maintained it religiously (oil at 5000, glow to manual system, injectors rebuilt, water pump, alternator, valve clearances adjusted yearly, replaced some leaking small gaskets (like blowby cover and oil pan). Now I have 534,000 and the last 15,000 was with an added turbo (Mercedes 300D turbo). Only issue is I have increased blow by but other than that she's still running. The body has been patched several times but as long as she runs that engine is going to get used.
As for the original question: which is the simplest diesel - I will not recommend any brands or types, instead I will say this:
the least amount of electronic parts, the more mechanical the better, engines with gear timing instead of belts work better. If it has more power then you require it will live longer (as it is not always being pushed to the max), parts availability is a good plus, longest reputation. The older engines were built better, they were heavier since steel was not a big issue then and much stronger because of it (on average). They were less efficient also but that was a trade off. On average, the older the engine design the simpler it was as technology was not replacing mechanics, they were built very basic for reliability and ease of repair. As we've witness here everyone has an opinion.
3B, H55, 1984, 2nd owner (first was a lady and I met the head mechanic at the Toyota dealer that always worked on the truck - nothing more then regular maintenance, belts, hoses, oil, etc.)
I got it at 326,000km, lifted it, abused it off-road, maintained it religiously (oil at 5000, glow to manual system, injectors rebuilt, water pump, alternator, valve clearances adjusted yearly, replaced some leaking small gaskets (like blowby cover and oil pan). Now I have 534,000 and the last 15,000 was with an added turbo (Mercedes 300D turbo). Only issue is I have increased blow by but other than that she's still running. The body has been patched several times but as long as she runs that engine is going to get used.
As for the original question: which is the simplest diesel - I will not recommend any brands or types, instead I will say this:
the least amount of electronic parts, the more mechanical the better, engines with gear timing instead of belts work better. If it has more power then you require it will live longer (as it is not always being pushed to the max), parts availability is a good plus, longest reputation. The older engines were built better, they were heavier since steel was not a big issue then and much stronger because of it (on average). They were less efficient also but that was a trade off. On average, the older the engine design the simpler it was as technology was not replacing mechanics, they were built very basic for reliability and ease of repair. As we've witness here everyone has an opinion.
wow, this was an interesting way to kill 30 minutes
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2X, great read considering i am trying to decide on the 1hz or 1hdt to go into my 80. On getting parts, 10 years in the future i want to be able to find parts quickly and seeing how 1hzs are still being put into cruisers (and other industrial applications) and 1hdts are not (marine apps only) , naturally leads me to the former. Looking at the fsm i understand both have different heads, injectors, injector pumps, cut off solenoid, basically the entire head....is this correct? I do have a preference for the 1hdt, so the next question would be besides the short block components what else is the same in the two?....that way i can just source 1hz parts.
Sorry to semi hijack....but i couldn't resist picking the brains of all the experts in here.....
Jonathan
2X, great read considering i am trying to decide on the 1hz or 1hdt to go into my 80. On getting parts, 10 years in the future i want to be able to find parts quickly and seeing how 1hzs are still being put into cruisers (and other industrial applications) and 1hdts are not (marine apps only) , naturally leads me to the former. Looking at the fsm i understand both have different heads, injectors, injector pumps, cut off solenoid, basically the entire head....is this correct? I do have a preference for the 1hdt, so the next question would be besides the short block components what else is the same in the two?....that way i can just source 1hz parts.
Sorry to semi hijack....but i couldn't resist picking the brains of all the experts in here.....
Jonathan
What parts are you expecting to need and in what circumstances would you need them?
A 1HZ in an 80 is a bit of a slug, toyotas own figures show it also using a lot more fuel. The links in this thread have expired, but read about the guy who owns both:
https://forum.ih8mud.com/diesel-tech-24-volts-systems/174430-1hz-vs-1hd-fte-economy.html
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yea unfortunately i have read in many threads that the hzj is a slug, that is why as i said, i prefer a 1hdt. Regarding parts, for example, even sor doesn't have many listed 1hdt engine components like cam shafts, heads, cranks, or even head gaskets, or water pumps etc etc. So i am worried in the future it will be impossible to obtain parts. Is my worries validated? Just trying to keep the cruiser for the rest of my life thats all..........
yes, the NA 1HZ is a slug. better than any other NA Toyota diesel though.
once you turbo it then the 1HZ REALLY comes alive.
i have owned a number of 1HZ equiped Cruisers and a number of HDT equiped Cruisers. I also have quite a few buds that own the HDT. the HDT has yet to show the fuel economy of the NA 1HZ. the turbo 1HZ will return better fuel economy than the HDT ... if ... you keep your foot out of it. drive it hard and all bets are off which will get better fuel economy.
now to be fair, the difference in fuel economy is not enough to shift the decision on which to own.
me, i am not a big fan of the HDT
but
i don't let web leaches make my decisions either.
you will be happy with either engine.
if you watch your boost, watch your EGTs and watch your water temp then the 1HZ turbo will last just as long as a similar driven HDT, if not longer ... and ... you will be able to get parts for the 1HZ for decades to come.
once you turbo it then the 1HZ REALLY comes alive.
i have owned a number of 1HZ equiped Cruisers and a number of HDT equiped Cruisers. I also have quite a few buds that own the HDT. the HDT has yet to show the fuel economy of the NA 1HZ. the turbo 1HZ will return better fuel economy than the HDT ... if ... you keep your foot out of it. drive it hard and all bets are off which will get better fuel economy.
now to be fair, the difference in fuel economy is not enough to shift the decision on which to own.
me, i am not a big fan of the HDT
but
i don't let web leaches make my decisions either.
you will be happy with either engine.
if you watch your boost, watch your EGTs and watch your water temp then the 1HZ turbo will last just as long as a similar driven HDT, if not longer ... and ... you will be able to get parts for the 1HZ for decades to come.
But you got such awesome economy from the HDJ81. Among the many claims in this thread is 10km/l +/- 0.5 for 4000km:
https://forum.ih8mud.com/diesel-tech-24-volts-systems/51487-hdj81-fuel-consumption-test-run.html
This is the infamous vehicle which still got 19mpg at 130-150km/h. Some other guy you know was getting 28-33mpg in one.
https://forum.ih8mud.com/diesel-tec...-fuel-consumption-test-run-3.html#post2409444
Or do your fuel economy figures vary depending on which ones you're trying to sell?
Or just fit a HDT and drive it how you like...
Any you reckoned Dougal had been on the crack pipe! ;p
Jamie
No time to look at the road, never mind the surroundings!
Gowans reported mileage was from an elevation of 3500 ft down to 300 ft, a steady down hill. also along the trans canada highway the wind blows west to east so this is a true story of down hill with a tail wind.
my "road to the sun" was an amazing run, i had never seen a HDJ81 return that kind of mileage before and have not since.
that was the one sold to Gowan and he returned the same mileage down here. he was running the 33s and a lift coming down.
too bad he tried to tow 5500 lbs behind it, he ended up selling it and getting a North American diesel.
one example doesn't make them all get that kind of fuel mileage. it did show that the autos return better fuel mileage than the 5 spds and more comfortable to drive at highway speeds.
as for lying to make a sale, did you not make the same accusations about my posts about PI?
that was an interesting reread, considering you are still calling me a liar 5 years later... i am glad to have met a few Kiwis over the last few years otherwise i would have a tainted view of Kiwis based on meeting you.
that was the one sold to Gowan and he returned the same mileage down here. he was running the 33s and a lift coming down.
too bad he tried to tow 5500 lbs behind it, he ended up selling it and getting a North American diesel.
one example doesn't make them all get that kind of fuel mileage. it did show that the autos return better fuel mileage than the 5 spds and more comfortable to drive at highway speeds.
as for lying to make a sale, did you not make the same accusations about my posts about PI?
that was an interesting reread, considering you are still calling me a liar 5 years later... i am glad to have met a few Kiwis over the last few years otherwise i would have a tainted view of Kiwis based on meeting you.
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Your 3B has dry sleeves.
I don't think Toyota ever built a wet sleeved engine. If they had, nearly every JDM engine would have had cavitation problems since they seem never to change coolant there.
The consistent 10km/l (shade over 28mpg) over 4,000km you claimed in that thread is pretty high for a 2.8 ton vehicle that big. You're now saying they get bad fuel economy, worse than the 1HZ versions. What has changed? Do you have an 80 series with a 1HZ that does even better than 10km/l?
Funny how the downhill with a tailwind part wasn't mentioned then.
I've never called you a liar but you are contradicting yourself quite badly.
as i stated over and over again i was surprised with the fuel economy on that test run. it turned out to be a rare occurance with the HDT.
if you look at an elevation map of Canada you will see that Calgary is almost the highest city in Canada and London is close to sea level.
if you also look at the wind patterns they flow west to east which is the same as the direction that Gowan took home.
if he was to do the reverse trip back out to Calgary i would hazzard a guess of a 5-7 mpg drop or maybe more if the head wind was strong.
you might have more experience with a 1HZ equiped 80 series, my experience is with the 70 series units.
of course you are talking only a few hundred pounds difference between the 81 and the 77 series add to that the boxy styling of a brick verses the smoother curves of the 81 and it will be a trade off.
i posted up the mileage and fuel consumption for others to verify or disprove. as of today i have yet to drive a HDT that returned anywhere near that consumption. it doesn't prove that truck didn't return the fuel mileage it did, it just proves that unit was an exception to the rule.
the 1HZ, in general, is better on fuel than the HDT in my experience and that is all i can go on ... experience.
if you look at an elevation map of Canada you will see that Calgary is almost the highest city in Canada and London is close to sea level.
if you also look at the wind patterns they flow west to east which is the same as the direction that Gowan took home.
if he was to do the reverse trip back out to Calgary i would hazzard a guess of a 5-7 mpg drop or maybe more if the head wind was strong.
you might have more experience with a 1HZ equiped 80 series, my experience is with the 70 series units.
of course you are talking only a few hundred pounds difference between the 81 and the 77 series add to that the boxy styling of a brick verses the smoother curves of the 81 and it will be a trade off.
i posted up the mileage and fuel consumption for others to verify or disprove. as of today i have yet to drive a HDT that returned anywhere near that consumption. it doesn't prove that truck didn't return the fuel mileage it did, it just proves that unit was an exception to the rule.
the 1HZ, in general, is better on fuel than the HDT in my experience and that is all i can go on ... experience.
just to be fair ..
turboed, intercooled and all the diesel that the inline it's capable. Tencha 2H
And that's was years ago .. I would take another one this weekend
turboed, intercooled and all the diesel that the inline it's capable. Tencha 2H
And that's was years ago .. I would take another one this weekend
So have you driven the 1HD-T and the 1HZ in similar vehicles?
What about the 4,000km of driving at 10km/l?
Toyota's own figures show at max torque the 1HZ takes 300g of diesel to produce each kw of shaft power, the 1HD-T takes 250g. 20% fuel saving right there.
The same saving is shown in toyotas own figures for the HZJ105 landcruiser (13 litres/100km) vs the HDJ100 (11 litres/100km).
and there is the problem, you are going by stats posted by a company wanting to sell a more expensive vehicle.
i have yet to come across any Toyota DI engine that is returning 20% better fuel economy than the similar IDI engine. even that amazing test run is still not 20% better than a 1HZ engine.
have you driven 4000 km in a 1HZ 80 series?
have you done the same drive in a similar day in a HDT 80 series?
as i have stated, and obviously you do not accept, the 77 and the 80 are very similar ...
i have yet to come across any Toyota DI engine that is returning 20% better fuel economy than the similar IDI engine. even that amazing test run is still not 20% better than a 1HZ engine.
have you driven 4000 km in a 1HZ 80 series?
have you done the same drive in a similar day in a HDT 80 series?
as i have stated, and obviously you do not accept, the 77 and the 80 are very similar ...
Fuel economy tests are done independently of the manufacturers, toyota has no influence over them.
No I haven't, but I know people who have owned the HZ powered 80 for years before trading up to an HD-T powered 80. They would never go back.
Nope, I don't see it.
No I haven't, but I know people who have owned the HZ powered 80 for years before trading up to an HD-T powered 80. They would never go back.
Nope, I don't see it.
since you are a figures man.
HZJ77
length - 4805
height - 1935
weight - 2130kg
O/D - .845
final ratio - 4.11
HDJ81
length - 4970
height - 1860
weight - 2220kg
O/D - .881
final ratio - 4.10
there is very little difference in weight.
what is gained in the shortness of the 77 is lost in the height (greater wind resistence)
final ratio the same
O/D close.
so, in theory, according to your figures a HZJ77 should NEVER get better fuel mileage than a HDJ81, in actuallity it should get 20% poorer or 20 mpg where the HDJ81 is reporting mid 20s. in the real world the HZJ77 is getting mid to high 20s and the HDJ81 is returning mid to low 20s ...
but
if the book says the real world figures are incorrect then i guess ...
the book is wrong.
HZJ77
length - 4805
height - 1935
weight - 2130kg
O/D - .845
final ratio - 4.11
HDJ81
length - 4970
height - 1860
weight - 2220kg
O/D - .881
final ratio - 4.10
there is very little difference in weight.
what is gained in the shortness of the 77 is lost in the height (greater wind resistence)
final ratio the same
O/D close.
so, in theory, according to your figures a HZJ77 should NEVER get better fuel mileage than a HDJ81, in actuallity it should get 20% poorer or 20 mpg where the HDJ81 is reporting mid 20s. in the real world the HZJ77 is getting mid to high 20s and the HDJ81 is returning mid to low 20s ...
but
if the book says the real world figures are incorrect then i guess ...
the book is wrong.
80 series is heavier, fulltime 4wd (turning three diffs not one) and automatic.
77 series is lighter, runs in 2wd with freewheeling hubs and manual.
Pretty lame comparison really.
Was it a different Crushers who drove an 80 series for 4000km while getting over 28mpg? Now you say mid to low 20's.
Or was that a different "real world"?
It's hard to nail down fuel economy claims that jump around depending on what you're trying to prove.
77 series is lighter, runs in 2wd with freewheeling hubs and manual.
Pretty lame comparison really.
Was it a different Crushers who drove an 80 series for 4000km while getting over 28mpg? Now you say mid to low 20's.
Or was that a different "real world"?
It's hard to nail down fuel economy claims that jump around depending on what you're trying to prove.