2H vs. 3B engines (1 Viewer)

[overton]

I’m not a diesel guy so I’m going to post this question for those who are. Assuming both engines are rebuilt, given a choice between a BJ45 Troopy with a 3B and an HJ47 Troopy with a 2H which would you prefer and why?

Greg

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The 2H is a 4.0 L (3,980 cc) inline 6, 12 valve OHV indirect injection diesel engine. Bore is 91 mm and stroke is 102 mm, with a compression ratio of 20.7:1. Output is 105 PS (77 kW) at 3,500 rpm - later production years 107 hp (80 kW) with 177 lb·ft (240 N·m) of torque at 2,000 rpm.
Applications

• Toyota Land Cruiser HJ47, HJ60, HJ75
• Toyota Dyna HU20, 30, 40, 50
• Toyota Coaster HB20, 30

3B[edit]
3B
Overview
Manufacturer Toyota
Layout
Displacement 3,432 cc
Cylinder bore 102.0 mm
Piston stroke 105.0 mm
Cylinder block alloy cast-iron
Cylinder head alloy cast-iron
Valvetrain OHV
Combustion
Fuel type diesel
The 3B is a 3.4 L inline 4 eight valve OHV diesel engine. Compression ratio is 20:1. Output is 90 hp (67 kW) at 3500 rpm with 160 ft·lbf (217 N·m) of torque at 2000 rpm.
Applications

• Dyna 4th, 5th, 6th generation
• Toyoace 4th, 5th generation
• Landcruiser 40/60/70
• Coaster 2nd, 3rd generation

 

[whitey45]

Greg,

I have had both and currently have a bj45 Troopy. The 2 h has a little more low end and pulls a little more but also weighs more. The 3b is not fast but feels like it has more pep and revs quicker. The key to the 3b is adding a turbo. It wakes it up and would race an hj47 any day! Lol!! I do have a soft top so the Troopy is a bit lighter. I know you are after a lhd and a bj45 is a great rig, but very hard to find. I did the rhd hj47 Aussie rig for a while, not hard to drive but just wanted a lefty. If you find a clean bj45, I think you would be very pleased with the drivability.

Brian

 

[Tapage]

2H quieter and smother

 

[Varty Yo]

I vote 3B

I love mine and will love it even more when the turbo goes on this week.

 

[Vossie]

2H, but im biased towards the straight 6's. 3B's a great motor, but a fresh 2H just has so much low end grunt.

 

[cuteo100]

2H. It's what was powering these 29-seat Toyota Coaster buses.

 

[Tapage]

2H. It's what was powering these 29-seat Toyota Coaster buses.

Always wonder details on tranny and R&P coz 2H ain't a power plant ..

 

[hj 60]

2h, I like the 6 cylinder sound.
But that bus, 29 people with luggage, 3000 kg, bus 3000 kg, I am surprised it would get past a stoplight before it went red again.
But with the trailer and all holiday stuff we might get to 2200 kg hj + 1500 boat + a lot of stuff 500 kg = 4200kg and no problems climbing to 1400 meters in the alps.

 

[Tapage]

it's all gearing ..

 

[OGBeno]

2H.

This shouldn't even be a question.

 

[Gun Runner 5]

2H.

 

[SugarBear]

We've owned & driven both quite a bit (driven the HJ47 vastly more though). HJ47 is turbo'd & H55F, but the turbo only run 4psi in boost. I can't speak to the gearing in the axles, but for all three trucks we started out in 2nd most of the time (not sure if that indicates axles or transmission). We always assumed the turob'd 2H was the bee's knees for 40 series troopies. It was a huge shock to learn how minimal the difference was between the HJ47 & the BJ45's. Even at altitude, the difference in acceleration & highway cruising was something you could see on the speedo, but not really feel. They were practically the same. The one big difference is the 47 will roll along at 80mph if you want to go that fast. We usually don't go over 75 max though, and realistically usually just drive 65-70. The one caveat would be that it has been years since the 47 didn't have a ton of gear & dogs in it when we are going somewhere. The BJ45's were usually more or less empty.

But having put thousands of miles on both models, I can honestly say that you'll be happy with either one.

 

[joekatana]

3B ! I have owned so many 3B's already in everything from early BJ42's to BJ70/73/75 and so on and the little 4 cylinder has never disappointed me.In your case it will probably be easier to find a 4 cylinder pu that has been used more gentle then any 6 cylinder because people who payed extra for that expected more of it.Pretty sure 3B parts are easier to find and will be supported more then the 2H.With stock tires and wheels there will always be enough power to get them anywhere you want.

 

[roscoFJ73]

Always wonder details on tranny and R&P coz 2H ain't a power plant ..

Low geared. 1st is very low and the diff ratio is lower than a landcruiser. You might get 100-110 kph constant on a flat road.
We went 300klms one night in a 3B powered coaster with 15 people on board, too drunk to remember much about the speed though.
Gearboxes are H50, H51 and M50. I had one repaired on my old 83 Dyna, the mechanic reckoned a Landcruiser t/case would bolt onto it.
There is a free FSM manual online that has the these gearboxes and the H55F in one book.

I would also vote for the 2H, I think they have a slightly wider torque band and smoother. But the 3B is generally considered to be stronger, maybe.

 

[Mookies]

My vote is a 1HZ (just kidding....well sort of. Unless you are getting either 2H or 3B CHEAP I would save some more pennies and get a more modern Toyota powerplant for a long term project)

2H is going to be ready for duty even with some drivetrain mods, etc. but is not as responsive (or reliable) with a turbo.
A 3B is easier to get parts for here and I agree with those above that they are bulletproof but you really need a low pressure turbo to make them come alive. My lady is picking up a BJ60 with a turbo'd 3B and it is a rocket ship but I remember rolling my eyes at the acceleration of a stock BJ.

Given both engines are rebuilt sitting in front of me.....for my needs....I choose the 2H and leave it stock.

A Troopy will be cool with ANY motor but just be honest about what you want to do with it.

 

[Dieseler]

I'd vote 12HT you will never look back both 3B and 2H are both great engines

 

[Gimme a 60]

I vote 3B. In spite of its slow nature, it has key features that make it superior to the 2H, for example. Sleeved cylinders are featured on the 3B allowing you to rebuild many times as it was originally produced by Hino/Diahatsu as a industrial engine used for for forklifts and coaster busses. 2H isn’t sleeved and can only be bored once. 3B also features oil cooling jets, allowing it to take a small amount of turbo boost to build more power. However both engines will get similar fuel milage and the 2H creates more power/torque, don’t froget about the lovely diesel sound either! I know this post is probably irrelevant now, but I’m new to this “diesel thing” and would share my thoughts for fun. Not like many of you will see this anyways.

 

[OPUS1]

I think this should b a question! It's relevant.

Hey OGBeno -do you know the production #'s on the BJ40s and BJ60's? If not, who might? If your a moderator on this forum aren't you supposed to be unbiased?
(Just asking the question no disrespect intended)

Depends on what you want. The 3B is better for longevity. Toyota cheaped out on the 2H (relatively speaking). sorta like a cat 3208. Seems like the 2h's run 3-400k then out. 3B's can go a lot longer. In the mines they would run them hard for 10,000 to 12,000 hours before rebuilding and go again. A 2H wouldn't do that.

What is a real diesel anyways. Is it the fastest? A lotta things that run faster die younger. I think a real diesel is one that will run and run like in a John Deere tractor or 18 wheeler. There was a Mercedes taxi in Greece that went 4.6 million Kms on three engines (but I bet it was never the fastest car on the street). This is the real power of a diesel - delivering countless hours to the owner - saving huge capital turnover costs over extended periods of time. The 3B can do that - the 2H - not so much. I was recently talking to a utilities crew - all young guys. one says - how old is your truck. I say 40 years to which they say - we change our trucks every five years! They said 20k/ year then trade at 100k after 5 years then 8 trucks go 800,000Km over 40 years. My 3B hasn't gone the 800,000km after 40 years but it could have. So what's the capital cost on 8 trucks compared to my one BJ60? I know they can afford it - they're gouging us all anyways -lol. Put this way - no self respecting trucker or farmer would switch their diesels for gas - they would go broke in no time (especially today!) A 2H is more of a consumer friendly diesel ( you know for the malls).

Power levels:

if you turbo a 3B it will come close to the 2H.
if you turbo the 2H for more power then you will likely shorten the life of the 2H - it won't take the turboing as well. The 12HT made the required improvements and is a great engine but had a short production run and not relevant to this thread.

there is ancient lore of custom heads built in Australia for the 3B's that could handle large amounts of boast and create big HP from the 3B engines.

Where are the Australians? They know more than anyone about Toyota diesels! Do any of you remember those custom 3B heads and what they were capable of?

 

[duncanrm]

2H isn’t sleeved and can only be bored once.

On the contrary, early 2Hs are in fact sleeved.

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[OPUS1]

So if the early 2H's were sleeved then Toyota did cheap out on the later ones. Not saying it's wrong - just another corporate decision at the time to enhance profitability no doubt. But now we are looking back and have the luxury of deciding on the bet options from old engines with 20/20 vision.