gas vs diesel for 79 HJ47

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Jul 17, 2007
Newbie looking for suggestions on future driveline swap for troopy. It has an H in it now but fear its on last leg. Like to get best performance out of this amazing HJ both highway and off. Not sure H rebuild will suit for more power. Any trans and gearing suggestions would help too.
More modern H series diesel.

2H with turbo, 1HZ, 1HD-T, 12HT, etc....

Any of those should work with your existing motor mounts, and give you more power, while keeping pretty good economy.

FWIW, I wouldn't change those H engine motor mounts for the world.

I have an 84 Troopie HJ47 which I bought in 1996. I had it turbo-charged in Melbourne, and was reasonably happy with the 2H that way. It is still an indirect injected engine though, and it is OLD diesel technology, no matter how recent the re-build. I have had the truck in the US since 1997, and in 2000 I put a brand new Vortec 350 in. I LOVE my 350, and the fuel economy is essentially as good as my turbo 2H was on the freeway. Around town I only get 14 MPG, where my 2H got 16, but with the cost savings on petrol, it is by-far cheaper to run than diesel.

I use the Chevy compressors to run my factory air con and power steering, and I mounted the 350 to the front of my factory H55F 5 speed. I put 3.73 gearing in the diffs as well, and at 80 MPH she is turning over 2700 RPM. With the cruise set at 80, and the air con going, I average 21.5 MPG driving from Santa Fe to Boulder. The best I ever got with my 2H was 24 MPG, but that was at 65 MPH (which was about her max speed without over-temping the exhaust).

I can now get parts at any parts store, I have more power than I could ever use, and I get the beauty of a Vortec under the bonnet(c: I hope this helps.

Sweet rig! I just bought a '79 pop top HJ-45 like that, should ship from Sydney on 4/19. Can you post up more pics? What is the interior like? Mine is a fully outfitted camper. Mine isn't as beautiful, though, I think it is rattle-can black. I haven't driven the diesel yet, but hear it's pretty gutless here at 7000'. So, like Josh, I'll recommend a SBC Chevy. In fact, I expect after I get mine, I'll transfer the camper parts to my 1980 HJ-45 that someone in AU put a 350 in. I love that truck with the V8.
my thoughts...........hmmm stick with a more modern diesel; turboed of course, prices of gas and diesel flutuate but you can always go biodiesel if things get really 0.02 .......she is a sweet looking rig; RHD or LHD?; either way she is a beaut!

Find a guy with say a '67 FJ40 with an F engine and swap him. OK, I'll do it.

Stay with the diesel. Stock, or close to it seems to retain the best value. Just my .02.
Thanks guys. The small block does sound tempting on part availability and familiarity alone. But it seems almost wrong to change out the heart of this rare TLC. I'm still on the fence and will run it till it breaks. It really could use some love in other departments (wheels, tires and leveling out the ride). Think it needs some more ground clearance with the old emu package @man-a-fre.
I felt bad about selling my turbo 2H and putting in a 350-until I drove my 'new' truck. I LOVE driving it now; it is just as fast, quiet, comfortable and efficient as a modern car- but it looks SO sweet! If you are keeping your Troopie as an investment, I think you will find that government bonds will offer a better return. If you are driving it as a vehicle to be enjoyed and to be functional- an H diesel will work far better in a fork lift.

I am living in Australia right now, and there are quite a few troopies round the joint. Many of the older ones have had either a 2H put in, or a Holden (which is a Chevy) engine put in. Australians do not tend to treat their cars with much respect (oil costs a fortune here, so many do not change the oils very often), so that may not be the best example to follow- but I know that I don't miss my turbo 2H at all- especially when I'm driving up I-70 to Moab at 75 MPH. Hope that helps.
Keep it diesel. I find it hard to beleive that is all the mileage you were getting out of it. I can't remember the modle of engine but someone that we ride with is getting in the low 30's on the highway with an FJ40. Mayb that is why it needed to be replacled? Also yes on the Turbo.
I have owned several diesel Toyotas, here in Australia and in the US. I know many people who say that they get 'in the 30s' but I've never, ever been one of them. I keep meticulous records of fuel use, and I am certain that I averaged high-teens to low twneties with an 84 2H turbo in a troopie. It is possible that you could get a bit more in a 40, but an in-direct injected diesel is not nearly as efficient as a direct injected one. If your mate had a 12HT, then that is entirely possible.

My 2002 Hilux with a 3 litre turbo diesel averaged 26 MPG at 60 MPG (the speed limit here), and 24 MPG around town. Bear in mind that these numbers are still significantly better than a petrol engine in similar rigs: my FJ40 with a 5 speed and 3:73 averaged just over 18 MPG driving from Phoenix to Santa Fe.

Don't get me wrong: I LOVE diesel, I just don't think that the old ones are all they are cracked up to be. My 3 litre in the Hilux is an amazing engine- but it is a 2002.


Hi, You get good economy out of a 2H in a FJ40 sports tub, the 2H diesel motor in a Troopie is working a little to hard due to the weight.

I would either turbo a 2H or get a 12HT for a Troopie, niece clean swap to certain point.

On the beach I am driving at around 70kph on average and doing around 1800 revs and when in soft sand I am reving at 1400 in second or third gear. I am using half the amount of diesel to gas because the light weight of my FJ and the high torque of a diesel suits what I needed it for.

At 100kph (60mph) the diesel is reving at 2500, when I had the 2F motor I could not keep the gas up to it on the beach, it was not to bad on the highway but when you put your boot into it on the beach I swear you could see the fuel gauge moving.

Plus I don't like storing gas in jerry cans at the beach house. With 110 litre longrange tank under the seat I am getting better than 11 litre's per 100klm, so that's over 1000klm per tank so I only need to fill it up once every month or so.
G'day Watrob,

so your diesel is on gas? That improves your economy by nearly 30% if the Diesel On Gas boys are to be believed. How do you like the system? What would your fuel economy be like on straight diesel? I agree with you though, storing gas is a pain, but you can use it in the barbie. My FJ40 LX here is on gas, and I fill it up from a home gas tank. I get that for about $.40 cents/litre delivered because I don't have to pay the road taxes. I use it for the stove and water heater as well. I use alot more gas than petrol, though, and if I had to pay bowser prices, it would not be worth running gas- I'd go stright petrol on that rig. I do plan to put a 12HT in it soon.

Here in Oz, I would say stick with the diesel, because parts are easy to get. In the US, parts for Toyota diesels are not generally available, other than at specialty shops. The 12HT is a wonderful engine, but significantly more expensive in the US than a Chevy Vortec 350.



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