12ht into hzj75

[1998hzj75]

Hey everyone, just chasing up some information, thinking about a complete conversion from my good old 1hz, which handled the turbo nicely until the turbo blew, into a factory 12ht. Would like to hear from anyone who has done the process before on what's needed and problems they encountered. Thought about it and came up with some questions, like, does the engine just slide straight into the 75 series mounts? Does the gearbox bolt onto the 12ht correctly? Do I need to run a different wiring harness? And what turbo was run stock standard with the 12ht?
(may add, if I am doing this I would be buying a reconditioned engine, not a donor car)

All helpful comments are greatly appreciated. Thank you.

 

[NZCruisers]

Done this conversion before on one of my 70's now in the process of doing it again to my other 70

Same deal as you , replacing my non-turbo 1HZ . Shes tired at 400K's.
Fairly straight forward conversion , the first 70 I did was to replace a 3B. I took a donor 60 and removed the entire engine/gearbox/transcase and put it all into the 70 as one. H55F gearbox bolted up and from there made new engine mounts to suit . With the 1HZ you'll need to fab up new engine mounts too as the HZ ones are a little out.

Are you running H55F gearbox? in which case you'll need the 12HT bellhousing to suit as the starters on the other side .
Assuming your Cruiser is 24V? Theres not much wiring wise to do but there is a little bit , alternator is on the opposite side to the HZ , you'll also need to run a vaccum line around the firewall for the alternator . First Cruiser I did was 24V so everything was fairly straight forward . The Cruiser I'm doing the conversion to now is 12 V so I'm converting everything to 24V makes things abit more fun
I used the 60 series clutch master clyinder as it was vaccum assisted and the fluid line was easy to bolt up ( slave clyinder on the 12HT bellhousing is opposite side to HZ , same side as starter)
Power steering was easy to hook up , on the first 70 I used the factory resorvoir on the firewall and went from there , took a line from the 60 to the power steer box. The 1HZ engine bay is a little different as the HZ as you know has the power steer resorvoir on the engine , I got a resorvoir that attaches to the firewall like my other 70 and mounted that. Also changed the clutch master to that of a 60 ( or earlier 70s)

Radiator wise I again used the 60 series one as the pipes were easier to attach. Had to modify the shroud extensively to fit. Ended up with a 2 piece shroud because the 70 bay appeared to be slightly shortly than that of the 60

Originally I was only going to replace the 3B 70 with a 12HT but then having driven the 12HT Cruiser and then driving the 1HZ Cruiser , saying it was gutless would be a mild comparison

Any other questions please ask , Hope that helps

 

[herbs]

Why not use a 1HDT or a 1HD-FT? Will bolt up with no need to fab up engine mounts.

 

[1998hzj75]

With the 1hdt, what are the main differences? The later model engine made me think there would be more electrics and wouldn't be possible without the harness, and is it the injector pump that's the different pump or is it another one?

 

[roscoFJ73]

With the 1hdt, what are the main differences? The later model engine made me think there would be more electrics and wouldn't be possible without the harness, and is it the injector pump that's the different pump or is it another one?

There is only one wire to the fuel pump on a 1HD T. The starting and running requirements are much simpler than 2h/12ht.
The pump on a 1HD T is a rotary pump ,the 12HT is an inline pump.The engines are totally different,the only thing they have in common is that they are both 6 cyl of approximate cc
The 1HD T should be much simpler install as the engine mounts are the same and the tacho and oil pressure will also work off the 1HD T senders.
This is becuase the 1HD T and 1HZ are basically the same engine.
The other thing I would be wary of is the fact you are putting a pre 1990 model engine into 1998 model vehicle.
In many countries this would be a no no.

 

[1998hzj75]

Sorry I meant differences between the 1hdt and 1hz, not 12ht

 

[Hulsty]

If you had a 2H 75 series it would be easy to put in a 12HT. A 1HZ 75 series has many differences. The engine mounts will need to be cut and welded, new gearbox input shaft and bell housing and then the electrical and shut down stuff. Where as a 1HDT would pretty much just bolt in and drive away.

 

[1998hzj75]

Thanks for the info, anyone know the exact differences between the 1hz and 1hdt?

 

[herbs]

Thanks for the info, anyone know the exact differences between the 1hz and 1hdt?

1hdt has direct injection, 1hz is the traditional indirect injection. Plus the factory turbo on the 1hdt. They mount up the same.

 

[1998hzj75]

So basically get the block, injector pump, injectors, and factory turbo. I can get the pump and block, any ideas/prices on the injectors and turbo?

 

[jb BJ73]

So basically get the block, injector pump, injectors, and factory turbo. I can get the pump and block, any ideas/prices on the injectors and turbo?

You're better off getting a whole motor. The pistons, rods, head and exh manifold are different. I think there are a couple of threads that talk about this.
Where are you located?

Edit: just read you're other thread, what's the availability of HDTs in NZ?

 

[1998hzj75]

I'm in Queensland, Australia, I was getting a whole new motor.

 

[jb BJ73]

I'm in Queensland, Australia, I was getting a whole new motor.

Whoops sorry wrong thread, yeah you should be able to find something over there, plenty of 4wd wreckers over that way

 

[1998hzj75]

Wouldn't be going through the wreckers, everything new/reco

 

[jb BJ73]

Wouldn't be going through the wreckers, everything new/reco

You're going to buy a brand new motor?

 

[1998hzj75]

Reconditioned engine, yes. Can't beat quality

 

[jb BJ73]

Reconditioned engine, yes. Can't beat quality

Ahh ok, was gonna say, brand new from Toyota would cost you upwards of $10000.

 

[1998hzj75]

Reco 1hdt is 6,600, reco 1hdft is 7,700, whats the difference between the two?

 

[Clint79]

Reco 1hdt is 6,600, reco 1hdft is 7,700, whats the difference between the two?

Is that exchange for a clapped out 1hdt.

The ft is a multivalve motor and different turbo ,

 

[1998hzj75]

That's not exchange, that's jut straight off the shelf, 1hd ft is a better motor then I take it?