More about the Troopy; improved brakes, cruise control, interior build: land-cruiser-78
The 1HZ engine of the Land Cruiser Troopy is not known for power with it’s modest 130 hp. It is a natural aspirated 4.2 liter diesel. When powering a truck with an allowed total weight of nearly 3.500 kg it feels a little weak. On the other hand it is extremely reliable and will last a million kilometers if properly maintained.
The 1HD-T turbo engine used in Land Cruiser 80 is the same engine block with a turbo added, and it delivers 162 HP. I have been driving both, and there is a difference. So why not install a turbo on the 1HZ and get more power?
Of course it is not as easy as that. There are a few important differences. 1HZ is indirect injection, 1HD-T direct injection. Indirect injection causes higher temperature in the piston and that is not the best combination with a turbo as more power will increase temperature. In addition 1HD-T is fitted with ceramic coated pistons to better withstand the higher temperature in a turbo charged engine.
You can install a turbo in a 1HZ, but there are a few important things to consider.
Aluminum melts at 650 Celsius. It is quite possible to reach this temperature that will burn holes in your pistons. To avoid that you should:
- Install a pyro / EGT (exhaust gas temperature meter) Never allow temperature over 550 Celsius.
- Run the turbo with a moderate boost, 10 – 15 psi, 0.7 – 1 bar. Up to 20 psi/ 1.4 bar if boost compensated and intercooled.
- Install an intercooler.
- Adapt driving technique. Use a low gear.
When I bought my Troopy previous owner had already installed a turbo. There are several turbos on the marked that will fit the 1HZ. The one installed in my car was a standard 1HD-T Toyota turbo and boost compensator. The boost compensator does as the name indicates, adjust the fuel so it is proportional to the air quantity in the cylindric which again is proportional to the boost.
Install a pyro / EGT
There was no pyro so that was the first thing to install. A pyro is a thermo electric sensor that withstands high temperatures. The cables for a pyro must not be cut or elongated as they are made of a special material. The sensor is installed in exhaust manifold trough a drilled hole. It is advisable to install pyro before turbo to avoid getting metal shavings from drilling of hole into turbo. Position I and II in picture are fine positions. It will give the best average temperature. Since my turbo already was installed I choose to remove the lid in the manifold at position III and drill a hole here, avoiding debris into manifold. This will only give you temperature from one cylinder, but there is no reason this should differ a lot from the others. Some people suggest to keep engine running when drilling. The exhaust shall then blow the shavings out. I don’t know…
Install intercooler / IC
Air-to-air intercoolers can be installed two places. In front of radiator, or on top of engine with air intake trough bonnet. There are also water based intercoolers, but they are more complex.
A front mounted IC is more efficient, but I decided to go for a top-mount because:
– I have air condition / AC and the radiator of the 78 is rather small so I do not want to restrict air flow even more. The troopy is known to easily get overheated, and I will use the car in hot climate.
– For me power is not the important thing. I am more concerned about over-heating and gas mileage.
– Ease of installation. It is difficult to get hoses to a front mount, especially wit AC.
In Australia there are many vendors offering kits for the 1HZ. I took a chance and ordered a kit from China, and to my surprise it was the same as a kit offered from Australia, but to a much lower price.
The kit consist of intercooler, brackets, a pipe and hose, a scoop, and an electric fan. The fan is to be installed underneath the cooler to suck air trough it. I also got hold of a thermostat from China that starts the fan at higher temperature than 40 Celsius measured in the intake manifold.
The cooler had a perfect fit to the intake manifold, and hose and pipe had a nice fit to the turbo. Only thing I changed was to make an additional bracket to avoid vibrations (see photo), and an additional heat shield. This is a stainless steel plate between exhaust manifold and IC.
The cut-out in the bonnet is the most scary part of this project. It hurts to use the grinder on that precious steel. So it is important to get the hole where it should be.
I started with placing a marker pen in each corner of the IC and closing the bonnet carefully. Then remove the insulation and drill holes in all corners. Then cut from outside. You have to cut off the stiffening of the bonnet. I popped on a angle steel in front of the opening to stiffen it a bit. Also I got a low frequent noise from the bonnet because of vibrations. This was solved by putting magnets on it where it flexed the most. The magnets was of the type you use with a hook for tools. I removed the hooks and placed two magnets underneath the isolation. The weight of the magnets prevents vibrations.
There is a 2-3 cm opening between bonnet and IC that should be closed with a rubber moulding. This is to avoid hot air from the engine to be sucked in. I used an old door seal for this.
Driving with turbo
I really cant say what it is to drive the troopy without a turbo since it was fitted when I bought the car. But compared to my 80 I will say it is slower, but not that slow. On highways I can easily cruise in 110 km/h, and overtake in 120. In long slopes you could want more power, and this is when you can overheat the engine. So better keep an eye on the pyro, and select a lower gear when it passes 500 Centigrades. A higher rev will force more air trough the engine and cool the pistons. You will see that instantly when shifting gear.
When going offroad you have enough power for normal overlanding conditions. I haven’t tried it in loose sand, but there my 80 also struggles.
Diesel consumption 1s about 1.4 liter/10 km on highway at 80 km/h. More when going faster than 100.
