Please tell me about the 1HZ

[Greg H.]

Moved from another thread.

Ok, I am not trying to be labeled a heretic or anything, but I have been hearing quite a bit about the 1HZ - why does it seam like is it some kind of Holy Grail?

I mean I see the specs. and while they appear to be ok ( I wouldn't mind replacing my 3B with one, just because it appears to be a basic no frills engine - but what do I know? ), what makes the 1HZ so special as compared to other Toyoda engines of simular displacement ( maybe I just don't know enough about engines - but I trying to learn ).

 

[roscoFJ73]

Basically its simple and gremlin free.
It gives reasonable power right across its rev range.
Known for its smooth and quiet operation.
Its compact but easy to work on.
If repairs are necessary in the field it doesnt need many gaskets. Most things can be sealed with some sealant.
The vac pump is separate to the alternator and outlasts the engine.
The engine only requires a single 12/24v wire to the solenoid to run.No edic or vac operated shut offs
It had a run of 16 years with little modification which means parts are largely interchangeable.(dont mix pre 98 timing gears and pumps with newer models)

The only bad thing is the injection pump has a shorter life than other similar pumps.

I believe when they designed it ,they took out all the less palatable aspects of the B and H engines. It was also designed for people who normally drive a gasser by running clean and not having a diesel smell surrounding it in the car park

 

[Greg H.]

How is it as far as modifications ( like a turbo or other stuff )?

If the injection pump isn't quite as good as similar pumps, is there a good aftermarket pump for it?

 

[brownbear]

I drove a lifted HZJ75 on 35's with a turbo and propane injection. It's the first time I have seen 140 kmh in a cruiser...

They do well with a turbo.

 

[Greg H.]

I drove a lifted HZJ75 on 35's with a turbo and propane injection. It's the first time I have seen 140 kmh in a cruiser...

They do well with a turbo.

What kind of mileage did you get?

 

[roscoFJ73]

How is it as far as modifications ( like a turbo or other stuff )?

If the injection pump isn't quite as good as similar pumps, is there a good aftermarket pump for it?

They were not really designed for a turbo ,but with carefull monitoring of EGTs they can last.
There is no other useful mods you can do
IMO ,for the cost of a 1HZ+turbo,you are better off buying a 1HD T with thicker pistons,direct inj and lower compression.

The pumps still last 250000+ and you rebuild them.
Aftermarket pumps and replacement parts made in china are rubbish.

 

[brownbear]

What kind of mileage did you get?

No idea it wasn't mine.

 

[Ron R]

What kind of mileage did you get?

The milage I get is 7,6 km per liter or a little over 13 liter per 100 km or about 18 miles to the gallon.
This is from my records during over 200000 k's and an average towing my caravan (1600 kg's), off-roading, freeway and urban driving.

During the over 230.000 k's I've done untill now, the valves where checked during regular intervals. Only one setting has been corrected because it was reaching it's limit, but not because it was out of limit.

I do oil changes every 5000 to 7500 k's depending on what I've done e.g. after a trip in the desert I will change at 5000 but I will at 7500 when mainly driving freeway and no towing at all.

 

[roscoFJ73]

The milage I get is 7,6 km per liter or a little over 13 liter per 100 km or about 18 miles to the gallon.
.

X2 . I get a little better on my 73 series ,about 12.5/100 and 13.5/100 in the 75. I guess its the extra 300kg.
I dont keep records but the figures dont vary much more than 5% from week to week

 

[Greg H.]

Interesting, I have been getting about 22 mpg with the 3B, with most of that around town.

I have been thinking that I would get better mileage with a larger engine, because you can go more than a mile or 2 around here without going up or down anywhere between a few hundred feet to a couple of thousand feet - with about 3000 ft differance between one end of town and the other ( and all that hill climbing makes that 3B work hard - even worse with the traffic lights stopping traffic on the middle of the hills )

 

[Ron R]

Interesting, I have been getting about 22 mpg with the 3B, with most of that around town.

Don't forget, my figures are an average.
I've had times I needed as much as 7,5 miles to the gallon (off-roading in muddy or sandy areas) but I've had times of about 23 miles to the gallon, driving solo and out of town.

The average weight of my rig is around 2300 kgs. That's including roofrack (fuelconsumption!!) aux fueltank of 120 liters and drawers.

 

[Tapage]

If you already have a 1HZ add a turbo and boost it to 10 PSI and enjoy .. but if you wanna buy a performance engine in the Toy diesel way 1HD-T it's the way that you want .. much more capable egine and the DI make the hole diference ..

 

[Greg H.]

If you already have a 1HZ add a turbo and boost it to 10 PSI and enjoy .. but if you wanna buy a performance engine in the Toy diesel way 1HD-T it's the way that you want .. much more capable egine and the DI make the hole diference ..

I would have to think about it.

One of the things that atracted my attention was the fact that it appeared to be a more simplistic engine than many other toyota engines.

I don't realy need high performance - I just need performance and relyability at high altatudes when going uphill, sometimes at grades of over 5%.

Don't get me wrong, the 3B has done a good job, but the combination of high altatude and steep roads sometimes means that I am probably pushing it harder than I should, to make it last.

Right now I have a over heating problem I'm trying to track down - I can drive all day around town, but once I start exceding 2200-2300 rpm for any leangth of time, like 30-45 min on the hwy, the engine starts getting hot ( unless it's a fair or wet day ).

 

[BillyGHusk]

so I have been following this thread and similar ones.

I will be building an expedition rig in the next 2-4 years. N. and S. America for a while. Either using a 55 or troopy for the base.

I will be swapping in a diesel.

The 1HZ and the 1HD-T are the club house leaders as the engine I will be using.

I like aspects of both. I like the idea of adding the turbo to the 1HZ since if something goes wrong with it(the turbo) it will still run.

How does using it in this type of rig affect everyones thoughts on which engine?

Tim

 

[Greg H.]

so I have been following this thread and similar ones.

I will be building an expedition rig in the next 2-4 years. N. and S. America for a while. Either using a 55 or troopy for the base.

I will be swapping in a diesel.

The 1HZ and the 1HD-T are the club house leaders as the engine I will be using.

I like aspects of both. I like the idea of adding the turbo to the 1HZ since if something goes wrong with it(the turbo) it will still run.

How does using it in this type of rig affect everyones thoughts on which engine?

Tim

I'll let you in on a little secret - I know first hand what it is like to drive a vehicle that has an engine that relies on a turbo - and have the turbo fail on the hwy - going from 65 mph to perhaps 20 mph ( with the throttle floored ) in about 30 seconds while in the center lane in traffic going through the middle of Portland OR at 4 in the afternoon.

I never want to do that again, and that is why I never bought another vehicle that had an engine that required a turbo.

How do think that influences my thoughts?

 

[roscoFJ73]

How do think that influences my thoughts?

Unrealistically because they are usually reliable.

Are you scared of pnuematic tyres also,they can blow out and you will not move at all. At least you kept going with the dead turbo

 

[rtarh2o]

I read a thread somewhere (can't remember) about a turbo with worn bearings, and somehow it started sucking oil and the engine was running on it, the owner couldn't turn the engine off because it wasn't running on the diesel any longer so his only choice was to let it run the engine out of oil. Apparently it ruined the engine. This seems pretty unlikely also (if it is even possible) but is one more reason I went with a 6.2 instead of the 6.5TD in my conversion. Alot to be said about simplicity, one less thing to go wrong no matter how much of a long shot it is.

 

[BillyGHusk]

the owner couldn't turn the engine off because it wasn't running on the diesel any longer

well he could have stalled it....I can't imagine it had that much power running on engine oil.....assuming this isn't an urban legend....

As far the the issue about running a turbo spec'ed engine. I realize they are normally very reliable. 10,000 to 100,000 of mile and work fine. As such I haven't ruled one out. I am simply thinking about simplicity. Being 1000 miles from a major city in S. America and having one less issue that could come up. Part of my asking the question was to find out if my concern is baseless.

Tim

 

[Greg H.]

Unrealistically because they are usually reliable.

Are you scared of pnuematic tyres also,they can blow out and you will not move at all. At least you kept going with the dead turbo

Tires don't bother me.

Had one blow and I was still able to get to a safe spot - shoot, I was beep bopping down the hwy a couple a years ago, and had all the lugs on the front passenger tire shear as I was doing 65 and rode my Cruiser to a safe stop on the brake rotor ( the wheel of course rolled to a stop about 200 yards further down the road ).

Exciting ?

Sure.

Scary?

Not even close.

What scares me is loosing power with a loaded logging semi behind me, and no way to get out of his way due to traffic, and seeing nothing but his grill in my rear view mirror as I was going slower and slower - That's what bothers me.

Sure, I kept going, just long enough to get out of the semi's way - I managed to find a gap in traffic and get to an off ramp where I lost what was left of the engine, perhaps less than 3/4 of a mile further down the road - couldn't even get the car off the off ramp.

 

[Ron R]

If I had to build an expedition rig I would go for simplicity, and simple simplicity.
Avoiding electric and electronic gadges as much as possible.
That would ask for a simple engine like the 1HZ and handshift, no auto.
Diskbrakes all around so you can easily check/replace the pads.
Simple in maintenance or virtually maintenance-free apart from regular oil changes.
Oh, wait, I am driving a 73. Why build one myself?