12-HT bj70?? (1 Viewer)

[landini BJ70]

hey guys I'm thinking about swapping my slow and tired 3b out of my 1987 bj70 for a 12-HT. Any one else done this, any help would be greatly appreciated
I have a 12HT gear box available as I know in the input shafts are different are the output shafts different? would I need the transfer case too??
my 3B is 24 volt and the 12-HT is 12 volt, how much of a pain is it to convert the nesercary components??
is there anyway of using the 3b radiator considering inlet/outlet are on different sides??
after market turbos? mamba, GTurbo, Munro, Highflow ct26??

wanting to know if its worth it before I bite the bullet.
Any help/ideas would be greatly appreciated

1987 24 volt bj70 cruiser
3B 5 speed manual

I did have a 3B+T motor in it but it overheated and I got it rebuilt and it never reliably stayed cool since so im not keen on the + T to the 3B

 

[Hulsty]

Pretty common and easy swap, just grab the equivalent HJ75 2H interfacing parts. With the gearbox you can swap on your existing transfer case.

 

[coldtaco]

14BT/15BT may be easier?

 

[Eurasiaoverland]

If you already have the 12H-T then go for it. If you're looking for a replacement engine then I would also suggest a 14B/15B as it will drop straight in, no need to change engine mounts or transmission cross member etc. And you can swap over your 24V accessories to the new engine. Either engine in turbo form will give more power and torque than the 12H-T, have better economy and much better parts availability.

 

[landini BJ70]

Cheers, yea I’m hearing you with that the 14BT motors are very hard to come across in New Zealand.

 

[Eurasiaoverland]

To answer your first questions:

You can use the BJ70s original H55F gearbox, apart from the input shaft, it's the same gearbox as is behind a 12H-T in a 60 Series (though not if your 12H-T came out of a Coaster).

What do you mean by converting the 'rest of the components'? If you mean finding 24V parts for the 12H-T, that's going to be pretty hard, you may find some in Europe. If you mean converting the rest of the vehicle from 24V to 12V, obviously that's a massive job.

You can use the 3B radiator, you'll need to modify the shroud.

Get a 24V 15B-F from a Dyna truck, turbo it and drop it in.

 

[landini BJ70]

To answer your first questions:

You can use the BJ70s original H55F gearbox, apart from the input shaft, it's the same gearbox as is behind a 12H-T in a 60 Series (though not if your 12H-T came out of a Coaster).

What do you mean by converting the 'rest of the components'? If you mean finding 24V parts for the 12H-T, that's going to be pretty hard, you may find some in Europe. If you mean converting the rest of the vehicle from 24V to 12V, obviously that's a massive job.

You can use the 3B radiator, you'll need to modify the shroud.

Get a 24V 15B-F from a Dyna truck, turbo it and drop it in.

Cheers for that. Planning to swap my Altanator off my 24v 3b and just changing wiring for starter motor, glow plugs, fuel cut off ect

 

[Jull]

I made a 12H-T swap on my Bj75, it is technically identical to the Bj70. These links may be useful to you (please use a translator Finnish => English )
Offipalsta.COM - Näytä yksittäinen viesti - BJ75 SA-1084 - https://forums.offipalsta.com/showpost.php?p=1435108&postcount=160
Offipalsta.COM - Näytä yksittäinen viesti - BJ75 SA-1084 - https://forums.offipalsta.com/showpost.php?p=1441257&postcount=214
Offipalsta.COM - Näytä yksittäinen viesti - BJ75 SA-1084 - https://forums.offipalsta.com/showpost.php?p=1445237&postcount=245

Whole story here:
BJ75 SA-1084 - Offipalsta.COM - https://forums.offipalsta.com/showthread.php?t=159385

Definitely if you already have a 12H-T, install it! With the same effort, you'll get those two missing cylinders...

 

[landini BJ70]

I made a 12H-T swap on my Bj75, it is technically identical to the Bj70. These links may be useful to you (please use a translator Finnish => English )
Offipalsta.COM - Näytä yksittäinen viesti - BJ75 SA-1084 - https://forums.offipalsta.com/showpost.php?p=1435108&postcount=160
Offipalsta.COM - Näytä yksittäinen viesti - BJ75 SA-1084 - https://forums.offipalsta.com/showpost.php?p=1441257&postcount=214
Offipalsta.COM - Näytä yksittäinen viesti - BJ75 SA-1084 - https://forums.offipalsta.com/showpost.php?p=1445237&postcount=245

Whole story here:
BJ75 SA-1084 - Offipalsta.COM - https://forums.offipalsta.com/showthread.php?t=159385

Definitely if you already have a 12H-T, install it! With the same effort, you'll get those two missing cylinders...

Cheers. Haha tempting to go for those extra two cylinders

 

[landini BJ70]

If you already have the 12H-T then go for it. If you're looking for a replacement engine then I would also suggest a 14B/15B as it will drop straight in, no need to change engine mounts or transmission cross member etc. And you can swap over your 24V accessories to the new engine. Either engine in turbo form will give more power and torque than the 12H-T, have better economy and much better parts availability.

found a 14b out of a dyan truck 350,000 kms

If you already have the 12H-T then go for it. If you're looking for a replacement engine then I would also suggest a 14B/15B as it will drop straight in, no need to change engine mounts or transmission cross member etc. And you can swap over your 24V accessories to the new engine. Either engine in turbo form will give more power and torque than the 12H-T, have better economy and much better parts availability.

found a 14b out of a dyna truck 350,000 kms, how long do they run good for? Keen to Drop it in a strap a turbo to it

 

[Eurasiaoverland]

With that many kilometres, it would depend on maintenance. If it has been very well maintained and not worked hard, it should have plenty of life left in it. But if it has been flogged by a string of owners with minimal maintenance, then it's anyone's guess. Can you test drive the vehicle? See the engine running?

 

[landini BJ70]

With that many kilometres, it would depend on maintenance. If it has been very well maintained and not worked hard, it should have plenty of life left in it. But if it has been flogged by a string of owners with minimal maintenance, then it's anyone's guess. Can you test drive the vehicle? See the engine running?

Yea the motor has been pulled and truck got deregisterd so I’d say it’s been flogged and not looked after

 

[sadam_husain]

is the work and cost of a 3b to 14b swap worthwhile with an 8hp gain before a turbo install

 

[Eurasiaoverland]

is the work and cost of a 3b to 14b swap worthwhile with an 8hp gain before a turbo install

I wouldn't put much faith in those Wikipedia numbers, that page is a mess. It states that the 3.2 litre 2B has more power than the 3.4 litre 3B, which doesn't really make sense. I think the 98 HP quoted for the 14B is either not a direct comparison (e.g. net vs gross etc), or just wrong. I have documentation (presumably from Toyota) rating the 14B-T at 140 HP, in which case 98 HP seems very low for the NA version. I would expect it to be around 115 HP, a bit less than a 1HZ. The 15B-F is rated by Toyota at 125 PS, the 15B-FT is at 155 PS and the -FTE at 170 PS, all of which are wrong on the page. See here for source: 15BF, 15BFT, 15BFTE Toyota OEM Power Specs - https://forum.ih8mud.com/threads/15bf-15bft-15bfte-toyota-oem-power-specs.1258570/

The other point is that while a turbocharged 3B has a good chance of failure, the direct injection 14B is much more robust with none of the IDI problems.

The snag with the 14B will be that you need to find a very rare turbo exhaust manifold, or fabricate one.