Another Perspective on the 'best 'diesel (1 Viewer)

[Dougal]

Dougal, you specs are for max operation. how many people actually see max operation of any engine? drop back to 2400 rpm (not 4200 rpm)and what is the comparrison?

Those figures are at max torque. Which on a diesel is pretty close to max efficiency and where they often run.

2200rpm for the 1HZ.
2500rpm for the 1HD-T.
1800rpm for the 1HD-FTE.

 

[arnott1t]

It could e pretty cheap it get a turbo on your existing 2h. The difference they make are fantastic. For seat of the pants buck I'd just turbo what you have. It is so so cool

 

[DanS HJ-45]

Does the 1HD-T also have the gear-driven power steering and injection pump?

After reading a few comments from posters in regards to the belt driven camshaft

The 1HZ and 1HD-T family share the same bottom end basically, so not only do they have a gear driven PS, vacuum and injection pump, but they use the exact same pumps.

They even share a maintenance manual.

The timing belt isn't something that concerns me at all, I'll just replace mine on an hourly interval or something. It's a half day job on my 2LT-E, and I do that at roughly 50,000 mile intervals just to be safe (that's an interference engine).

Fascinating info there Dougal, the engineer in me understands the DI vs. IDI efficiency argument, but I need a real world anecdote to convince me. There's a 60 here that had a 1HZ/turbo and replaced it with a 1HD-T, right? Did we get a good mileage measure pre and post swap?

Dan

 

[rideglobally]

4BD2TC to a H55

do i understand correctly that you mated a isuzu 4BD2TC to a H55 transmission? i have been researching this and i though it could not be done and an adapter do not yet exist. i will send you a pm. thanks

You mentioned Isuzu...Well I installed a 4BD2Tc last summer and have been quite happy. Great performance, good fuel economy, very quiet, and a fairly easy install.

I kept the 3:70 gears and already had a H55 5 speed trans, so a 70 mph cruise is no issue. For people in SoCal or those who know Interstate 5 North of LA, I can drive the whole section to the central valley at 70+ mph in 5th the whole way no issue! Not to bad.

The engine has a great layout for a 60 swap...It just fits nice. For parts, any GM truck dealer can get parts, and most will service the engine. Isuzu has quite a few dealers and parts are not to bad price wise.

The 4BD1/2 engines were in many trucks in the US and can be found for very low prices. Overhaul kits are around $1,300.00 US and have press in liners and coated cranks. Stout engines with long lives. Some debate on which model is better/long lived, but both are good IMHO.

Check out 2BTswaps.com and go to the Isuzu section for great help and advice on these engines.

Check out the link under my signature for my swap with pictures. I think it looks almost factory and works factory, only better.

Just another option.

Good luck on your swap.

Doug

 

[Dougal]

Fascinating info there Dougal, the engineer in me understands the DI vs. IDI efficiency argument, but I need a real world anecdote to convince me. There's a 60 here that had a 1HZ/turbo and replaced it with a 1HD-T, right? Did we get a good mileage measure pre and post swap?

Dan

There are guys in aussie who've swapped 1HZ's for HD-FT's, but I can't find the info right now. Enough googling should pull it up.

Or just compare HZ and HZ-T cruiser fuel consumption figures with HD-T/HD-FT and the FTE in the 100 series.
The 1HZ is about 2 litres/100km worse off. The FTE's are in the much fatter 100 series but fuel consumption is no worse than the HD-T 80 series.

 

[Radd Cruisers]

Fascinating info there Dougal, the engineer in me understands the DI vs. IDI efficiency argument, but I need a real world anecdote to convince me. There's a 60 here that had a 1HZ/turbo and replaced it with a 1HD-T, right? Did we get a good mileage measure pre and post swap?

Dan

The difference will be in the 10% arena.

The fellow who owned the HDT60 passed away a few weeks ago in a crash.

~John

 

[Henry James the 47th]

It could e pretty cheap it get a turbo on your existing 2h. The difference they make are fantastic. For seat of the pants buck I'd just turbo what you have. It is so so cool

Well, I realize that and have thought about flipping the manifold and putting on a turbo, or similar. Thanks to the many excellent write-ups here on 'mud about turbo'ing 2H's, I am pretty clear on the process.

However, the engine has around 350,000km on it right now, and while I would net a boost in power, I would also hasten the demise of the engine. If I gained a significant jump in fuel economy, it might be worth it, but I'm not so sure I would get much improvement.

My next diesel is very likely to have a turbo however, and maybe an intercooler if that can be shoe-horned in.

Anyone have a good idea about the dimensions of the 1H family of engines in comparison to the 2H/12HT?

 

[Henry James the 47th]

The difference will be in the 10% arena.

The fellow who owned the HDT60 passed away a few weeks ago in a crash.

~John

Sorry to hear that.

A question, if I might be a little rude: was the 10% gain in fuel economy over the 1HZ, or over the original 2H he had in the truck? Why did he change the 1HZ for the 1HD-T?

What sort of fuel economy would you speculate that my 47 would return with a 1HD-T considering that my truck is considerably lighter than an HJ60 (though hardly what you might call aerodynamic)?

 

[crushers]

a turbo DOES NOT shorten the life of an engine ...
the drivers right foot does.

 

[doug720]

do i understand correctly that you mated a isuzu 4BD2TC to a H55 transmission? i have been researching this and i though it could not be done and an adapter do not yet exist. i will send you a pm. thanks

I used a Isuzu swappers adapter ring to make the 4BD engine a Chevy bolt pattern. Then a Downey Off-Road Chevy v8 to Toyota trans bellhousing was used with a Chevota clutch. No issue.

If you check my build thread, there are pictures of the set up. Also check "flcruiser" here on Mud. He has the same set up.

Doug

 

[romey]

a turbo DOES NOT shorten the life of an engine ...
the drivers right foot does.

wonder what happend to eric's turbo on his bj60. remember, you guys did a compression test on it and i think the figures were okay, and his rig had over 600K kms!

nobody's mentioned a PZ motor yet? then turboed?

 

[DanS HJ-45]

Anyone have a good idea about the dimensions of the 1H family of engines in comparison to the 2H/12HT?

I'll try to take some "side by side" measurements of the 1H and 1HZ for you this afternoon....

Dan

 

[crushers]

almost identical in length, width and weight.

 

[DanS HJ-45]

almost identical in length, width and weight.

Well, the camera battery is dead, so I won't post pics, but pretty much this. Looks to me like the 1HZ is about an inch longer than the H, but no other real dimensional difference.

Slightly longer, but not enough to cause real problems.

Dan

 

[Radd Cruisers]

Sorry to hear that.

A question, if I might be a little rude: was the 10% gain in fuel economy over the 1HZ, or over the original 2H he had in the truck? Why did he change the 1HZ for the 1HD-T?

What sort of fuel economy would you speculate that my 47 would return with a 1HD-T considering that my truck is considerably lighter than an HJ60 (though hardly what you might call aerodynamic)?

You're confusing two subjects here. Direct vs Indirect injection - when you compare the 2H to the 12HT or the 1HZ to the 1HDT then you are going to gain a LOT of power for going direct injected and around 10% in fuel economy (using my real world numbers). The other note is that with the extra power one also tends to drive faster - and yet there is still that ~10% advantage in fuel economy.

The 1HZ was swapped out due to bent rods from water ingestion. The comments about the 1HDT from the same fellow was that it was much more powerful than the 1HZ.

The RPM range that these engines operate at has a very significant effect on fuel economy. You want to be close to the torque peak at your typical (fast-ish) highway cruise, but not past it for fuel economy.

With the 12HT there is a very large gain in fuel economy if you can keep it under about 2150 RPM, over that and you're into using a lot of fuel, under that and gentle on the throttle and you can get mid 30s in an HJ61 (I have gotten as good as high 30s, but going moderately slowly on non-hilly highways at about 2000ft elevation). Typical mixed town/highway driving where I live (and you know the area well enough) I get about 28 mpg imperial all the time; it is very consistently the same at about 10L/100km. Cruising from Alberta to BC with 4 people, mountain bikes on the back and camping gear for 4 people... just less than 9L / 100km over 850km (1 tank from Alberta to Chilliwack).


~John

 

[crushers]

john, you will always get better fuel economy heading down hill.
Alberta is roughly 3500 ft, chilliwak is what? 300 ft? that is a steady down hill ride of 3000 ft. that is similar to the bloke that got 33 mpg driving his 81 back from Calgary AB to London Ontario, steady down hill drive from 3500 ft to 350 ft WITH the steady jet stream tail wind. i have yet to meet a HDJ81 that has returned a steady +25 mpg and yet i have met a number of 30 MPG 1HZ engines.

as you say, it is HOW the engine is driven that will relate to fuel economy. vehicles driven in back water Ontario will always return better fuel economy than vehicle driven in Alberta, 80 k/h speed limit vrs 110 k/h speed limit, coupled with the fact that MOST drivers speed, that extra 30 k/h makes a HUGE difference on fuel economy.

 

[Henry James the 47th]

Some good points there to be sure.

In my HJ47 I find that to roll down the highway at 65 mph I am doing 2850 rpm or so in 4th gear, that's with 4:11's and 32" Toyo tires. To make that speed at around 2150 rpm, as John mentions with the 12HT, I would need different gearing, likely a 5th gear in the transmission and 3.7 in the diff. And for another thing, the 2H just doesn't have enough oomph that with those gears I could move along at 65 mph. Maybe on the flat, but as soon as a slight hill comes along I am down to 60..even 55mph. On a longish steep hill, i may have to drop into 3rd gear...

So, normal highway driving does not return excellent fuel economy for me - more than 20 mpg, but not much more. I dream of 30 mpg!

 

[crushers]

30 mpg US will not happen at that speed, sorry, with any diesel engine.

the 3.7 will help, the 5th will help but there comes a time when the engine has to work harder to move the mass with improper gearing.

if you did a chop to the roof, slammed it down and ran smaller tires adn turbo'd the 2H you MIGHT score you mileage.

mid 20s Can is average for most Toyota diesels IDI or DI, turbo'd or not at 100 k/h ...

here is the funny part (for me) we talk about an extra 4-6 mpg as if it was the holy grail but in reality you are still almost doubling a gassers mileage.
unless you are putting 40K or 50K a year on the mileage increase is negligable on the pocket book ...

 

[Henry James the 47th]

Yes, you're quite right about the fuel economy. It's important to me - one of the reasons I chose to go diesel in the first place - but it's not the most important thing.

The 2H is hardly a powerhouse, and it is on those slight hills where I slow to 60 mph and traffic mounts up behind me and I can't pass the semi on the right to get over to the slow lane where I wish I had a few extra ponies at work.

If I could get an engine with 140 hp or so, and still return the same fuel economy that I get now, then that would be something, and that seems quite attainable - for a price.

 

[AustinCruiser]

Are 3:70 gears available for a locked 1993 LC80?

Thanks, Ed