Engine Family Comparison: 1HZ, 1HZ-T, 1HD-T, 1HD-FT (4 Viewers)

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So you are planning to run a 55 in that build with an FT? If so, what are some factors that led you to make that decision, as I am sure you had all transmissions available as an option.

Yes H55.

We want to run the split case, can’t run that behind the H151. In addition the H151 is long which will push the shifter to far back. Trying to retain a bench seat.

Cheers
 
So guys this helps a lot when planning a build, doing upgrades or swaps. I like this one,


Run all your numbers through there. FT redlines at 4k, no worries at all cruising it at 2850rpms all day long. For us and the 67 pickup build, that is 85mph in 5th with an H55.

Cheers

Thanks so much for that gearing calculator. It was very helpful!

I currently have the 2F engine with H55F trans. I'm running 33" tires, 4.56 diff gears, and a 4:1 (low)/1.1:1 (high) split t-case. So I'm losing 10% overdrive with the low gearing in the split case. I was concerned this would be geared WAY too low. But it looks like I'll be cruising at about 60mph at 2,500 rpm in 5th gear. Not bad. It's even better if I swap to a 1HD-FT because it makes maximum torque at 2,500 rpm. Perfect!

If I really want better overdrive gearing for highway cruising, I can always swap my 4.11 diffs back in. Or go to 60 series 3.73 diff gears.
 
I think you'll find in reality most FT's produce their max torque much much earlier than that. I'm also running the 3.73 gears in my FT and it's a perfect match

Roger that. What transmission are you running?
 
I think you'll find in reality most FT's produce their max torque much much earlier than that. I'm also running the 3.73 gears in my FT and it's a perfect match
My 1HDT made max torque at 1800 with the red wheel - with 4.11 and 285/75/16 was IMHO still a little short geared, would have been perfect with 35s with the H151 trans
 
Roger that. I was going off Engine-Specs.net. But it looks like most dynographs are producing max torque earlier than that. 1,800 to 2,400 RPMs seems to be the fat spot.
 
So after a lot of consideration, I'm vacillating on my decision to run the 1HZ/1HD-T/1HD-FT series of engine.

I was initially interested in this engine-family because several knowledgeable enthusiasts had advised me that engines and parts were relatively common and affordable. Heck, there is a 1HZ for sale in the classifieds for $2,750 at the time of this post. And the 1HZ is still currently manufactured by Toyota.

But I also know that I want a turbocharged diesel with direct injection and a mechanical fuel pump. Sure, I could always turbocharge a 1HZ and it would more than likely meet my needs. But I think I would always wish I had saved my pennies for a factory turbocharged engine. I could do a 1HD-T, but I think I would ultimately want the FT over the regular 1HD-T. So now we're into expensive engine territory and 1HD-FTs are not that common. The whole reason for considering this engine family (availability/price) is gone because I'm interested in the 1HD-FT.

So I'm reevaluating my options and considering the 12HT. I like the 12HT engine because:
  • Factory Turbocharged
  • Direct Injected
  • Timing Gears rather than Timing Belt
  • Exhaust on "correct" side of vehicle for routing around frame/t-case
  • Direct Bolt-In to 40 series frame w/ HJ45/47 Bellhousing and Engine Mounts
  • Correct Input Shaft for H55F (2F and H/2H/12HT use same shaft)
  • Legendary reliability

Obviously they are not as common and they are older, which means parts are getting hard to find.

Either way, I'm going to keep researching and evaluating my options. I really appreciate all of the input from all of the members in this thread.

Thanks again!
 
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I believe this forum and every forum acts as an echochamber and amplifies "problems". Like BMW forums talking about vanos and rod bearings, CTSV forums talking about superchargers and AMG forums talking about headstuds.

Im sure theres a ton of aussies driving the piss out of 1hdts and not giving a care in the world about BEBs
 
I believe this forum and every forum acts as an echochamber and amplifies "problems". Like BMW forums talking about vanos and rod bearings, CTSV forums talking about superchargers and AMG forums talking about headstuds.

Im sure theres a ton of aussies driving the piss out of 1hdts and not giving a care in the world about BEBs

I agree 100%. It used to happen on Nissan 300ZX Twin Turbo forums all the time back when I was into sports-cars. Someone would come out with a new intercooler and the first question was, "Have you flow tested it???!!!" A straight aluminum tube flows great. But it doesn't cool an intake charge for sh*t. That was just the default reaction to new intercoolers.


I'll remove my comment about BEBs because I don't want that skewing the logic. I would ultimately want the 1HD-FT regardless.

Also, the same argument could be made for the 12HT - "It's too old. They only made them for 5 years. You'll never be able to find parts for it!" Is this an echo-chamber amplification for a "problem"?
 
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I had a turbo 1HZ then converted to a FT which I love and has great power but there's things the FT just can't do which the 1HZ can. Indirect injection engines by their design are so much smoother, have a broader range of torque, continue to make power right up till redline and have so much more idle/off boost torque with their much higher compression ratio which is awesome for off road use. IDI does have its draw backs though and the fuel economy, emissions and cooling issues ended up being prioritised which lead to DI taking over. If and when I ever have any troubles with my FT I've already decided I'm putting the HZ back in.
 
I had a turbo 1HZ then converted to a FT which I love and has great power but there's things the FT just can't do which the 1HZ can. Indirect injection engines by their design are so much smoother, have a broader range of torque, continue to make power right up till redline and have so much more idle/off boost torque with their much higher compression ratio which is awesome for off road use. IDI does have its draw backs though and the fuel economy, emissions and cooling issues ended up being prioritised which lead to DI taking over. If and when I ever have any troubles with my FT I've already decided I'm putting the HZ back in.

Great intel. Thank you. I still may go the 1HZ route.
 
I believe this forum and every forum acts as an echochamber and amplifies "problems". Like BMW forums talking about vanos and rod bearings, CTSV forums talking about superchargers and AMG forums talking about headstuds.

Im sure theres a ton of aussies driving the piss out of 1hdts and not giving a care in the world about BEBs

Australia is where the BEB problems surfaced. Because they spend more time than anyone else driving in hot conditions at steady load for hours at a time. In comparison New Zealand didn't have the same failure rate. Because our driving is more varied, our climate cooler and we don't load vehicles up with a whole ton of coolers, water and beer.

It's not a problem until your engine seizes and destroys the whole bottom end. One Aussie story I read had a guy accept $700 for the remains of his built up HDJ80 after it lunched itself in the middle of Australia. Tow/recovery fees were worth more than the vehicle.
 
As you know I have a 13BT I rebuilt last summer. A 13BT is a 12HT minus 2 cylinders basically. The 13BT was made for fewer years than the 12HT.
I will say there are still a surprising amount of parts I was able to get. Engines Australia has a full rebuild kit for the 13BT and 12HT, plus sleeves, Alfin pistons and basically everything you need.

there are also achunk of parts you won’t Be able to find new. Head, block Probabaly the camshaft and all sorts of bits of pipes, hoses little things you may never need to replace. You would have to make/modify search some of those parts.

that was a long winded way to say if you want a 12HT, you can find one and spare or used parts. Australia is a great place to look. It will be harder to find than 1HZ or other parts,but the majority you should be able to get. It also matches up to your H55f already.
another option if you go 12HT is to stock pile parts like the 70 series folks do. Get a spare head, all sorts of parts just to have them and not have to worry about finding later. A lot of 2H parts cross over, I’ve heard valves, can, lifters, valve train etc.

Performance wise, you will be quite impressed with a 12HT in a 40. People always look at specs on paper and say it only has 134hp 230tq, but that’s deceiving. True it’s no modern engine or built Cummins but it will scoot a 40 along quite well.
My 13bt carries my BJ74 which is heavier than a 40 nicely stock. I have power available in upgraded turbo, inter cooler, fueling.

gturbo, Munro racingturbos and wink 4x4 build custom turbos for a 12HT. All sorts of options. The exchange rate is pretty good Now.

wink 4x4 turbo and12ht in a troopy. Looks to move pretty good and sounds awesome
 
As you know I have a 13BT I rebuilt last summer. A 13BT is a 12HT minus 2 cylinders basically. The 13BT was made for fewer years than the 12HT.
I will say there are still a surprising amount of parts I was able to get. Engines Australia has a full rebuild kit for the 13BT and 12HT, plus sleeves, Alfin pistons and basically everything you need.

there are also achunk of parts you won’t Be able to find new. Head, block Probabaly the camshaft and all sorts of bits of pipes, hoses little things you may never need to replace. You would have to make/modify search some of those parts.

that was a long winded way to say if you want a 12HT, you can find one and spare or used parts. Australia is a great place to look. It will be harder to find than 1HZ or other parts,but the majority you should be able to get. It also matches up to your H55f already.
another option if you go 12HT is to stock pile parts like the 70 series folks do. Get a spare head, all sorts of parts just to have them and not have to worry about finding later. A lot of 2H parts cross over, I’ve heard valves, can, lifters, valve train etc.

Performance wise, you will be quite impressed with a 12HT in a 40. People always look at specs on paper and say it only has 134hp 230tq, but that’s deceiving. True it’s no modern engine or built Cummins but it will scoot a 40 along quite well.
My 13bt carries my BJ74 which is heavier than a 40 nicely stock. I have power available in upgraded turbo, inter cooler, fueling.

gturbo, Munro racingturbos and wink 4x4 build custom turbos for a 12HT. All sorts of options. The exchange rate is pretty good Now.

wink 4x4 turbo and12ht in a troopy. Looks to move pretty good and sounds awesome


Your timing is fortuitous - I just found an HJ47 bellhousing and clutch fork on eBay Australia. Just looking for front engine mounts now (and an engine!).

The fact that the 12HT just bolts right in, I can use my current H55F setup, and the exhaust is on the correct side all swayed me to 12HT.

I can still get a 1HZ series if I want...it's just a great excuse for another Land Cruiser!
 
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I’m sure some of the V8s make at least 300hp and 300lb-ft at the flywheel.

Any engine in this family will put out higher torque numbers than that with a turbo upgrade and decent tune

I am actually getting ready to swap in an H151 which was paired with the FT and FTE by Toyota and comes with a large flywheel and finer spline input shaft

H151 has a thick input shaft with 14 spline input shaft mated to 300mm clutch. H150 had thinner input and 21 spline input mates to 275mm clutch.
Fly wheel is also different with different clutch locating dowel size and location

Honestly, the R151 drives and shifts best but it is not a hd trans.

R151 is a light weight box with a poor reputation behind a turbo diesel in Landcruisers in Australia, they also suffer a lot of fifth gear failures. If choosing a trans, I'd avoid them like the plague.
They do shift nice though.
 

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