HZJ78- 1HZ Intercooler (1 Viewer)

[Erwin]

Hi

I recently got me a HZJ78 2001 – 1HZ engine where previous owner had installed an aftermarket turbo. From what I can read it is a good idea to put in a intercooler to prevent too high exhaust temperature.

So I was wandering if anybody use this top mounted IC from HP Diesel, Australia:

https://hpdiesel.com.au/products/intercooler-kits/toyota-landcruiser-70-series-1hz-141.html

It is mentioned in this thread, but it is not said if anybody actually have it installed:

70 Series Intercooler Debate


I am aware that a front mounted IC is more efficient, but for me the reasons for wanting a top-mount are:

- I have AC and the radiator of the 78 is rather small so I do not want to restrict it even more. 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.

The car is using 1.4 liter/10 k on highway driving at 80-100 km/h, witch I think is rather high. Even with a pop-up roof. Could be the pump is not properly adjusted, though.

Any other top-mount IC that can be recommended? There are cheaper no-brand’s on eBay, but hard to tell the quality.

 

[Feistl]

Water to air top mount?

I know it's more cost/complexity but means you don't need to cut a vent hole in the bonnet and if you have a large reservoir then you'll protect the engine from heat spikes...

You can mount the heat exchanger either up front or even in the rear of the rig. It doesn't really matter if you damage the heat exchanger as it'll just mean no intercooling (but the engine will still run).

Cheers

 

[mudgudgeon]

14L/100km is not too bad at all for a 1HZ, particularly if you have rooftop tent on.

With turbo, if you drive carefully for economy, you might do slightly better, but won't be a lot.

I would seriously look at a front mount even in your case.

There's Aussie guys who have had issues with top mounts not providing enough cooling, and fans failing repeatedly who have changed to front mount with great results.

There's two ways to look at the effects of a front mount.
Yes, a front mount will mean your AC, and radiator will see warm air from the intercooler when you are working things hard.
Intercooler well potentially reduce the overall heat load your cooling system has to deal with by reducing intake air temp to ambient, and providing greater power and efficiency in the combustion process. A good intercooler could give you gains of 20-30%, so 20% more power without adding in additional fuel means you work the engine less hard.

If a FMIC is installed with a foam seal between intercooler and radiator, you prevent air passing around the IC, and give it maximum effectiveness.

With a topmount, the intercooler doesn't get direct air flow. And it gets air that has been heated passing through the radiator, plus radiant heat from the top of the engine and exhaust. Fans also have to deal with a very high heat load. Heat in cables causes resistance which causes a voltage drop, which in turn increases the amps drawn by the fan, which lowers voltage, and kicks off a viscous cycle that means the fan is unlikely to run at full capacity.
This all means a top mount is not going to be as efficient, which means you burn more fuel to mak same power as you would with FMIC. More fuel burnt equals hotter combustion which is 1HZs nemesis.



You don't say what turbo you have?

Turbo choice on a 1HZ is every bit as important as intercooling, and monitoring EGTs. An intercooler and EGT monitoring won't make up for mismatched turbo.

A turbo that is well matched will give you boost early, and throughout the rev range. But you also need one that is going to provide high volume of air flow without the turbo working outside its efficient range.
If the turbo boosts late, or needs a lot of fuel to get it working, you'll get a lot of combustion heat until the boost comes on.
If the turbo doesn't flow enough air and is working hard, you get excess heat from the compression of the air.

 

[mudgudgeon]

Have a look here, The official 1HDT Intercooler thread
@SeaJay had issues with TMIC, and changed to FMIC. Discussion probably started before the linked post.

 

[mudgudgeon]

I would also skip water to air intercooler.
You still have to shed the same amount of heat load. An aluminum A-A core does this far more efficiently than a water to air radiator. Plus the radiator needs to go somewhere it gets air flow through it, guess what, that's in front of your main radiator.

The added complication is not worth the hassle, and gains are highly debatable.

With a 600x300x50 air to air core, as heated intake air passes through it, the temperature in the core drops rapidly. Air may be 70° if the turbo is working hard as it enters, but will usually be down to ambient by the time is passes to the outlet.
This means not all of the air passing through the FMIC to the radiator is going to be heated significantly

 

[Erwin]

@mudgudgeon The turbo kit is ths from euro4x4parts, installed by PO:
http://www.euro4x4parts.com/parts/mtk1002_turbo_high_performance_turbo_kit.html
What brand the actual turbo is I dont know, but euro4x4parts usually sell good parts.

 

[mudgudgeon]

It's a Toyota turbo, looks like it's a 1HD-FTE turbo, or CT20b.
Looks like it's using a Toyota manifold and Toyota dump pipe too.

Good for you, it's well suited IMO. There is better aftermarket turbos available, but that combo is a good solid starting point.

 

[Erwin]

@mudgudgeon I have read trough quite a bit of The official 1HDT Intercooler thread. A lot of interesting stuff there. But one thing I was wondering, why do you install the fan under the IC, on a top mount. If heat is a problem, wouldn’t it be better to have it on top?

Then the fan could be inside the cut-out, allowing for a higher IC.

 

[FJRanger]

I'll 2nd mudgudgeon, go for the front mount.

On our 80 I initially went with the cross country 4x4 top mount for the same reasons you are using. It worked well & I'd only need to watch the EGTs when towing our Kimberly SportsRV, transmission temps were more of a pain to keep in check. However, I've had to replaced the fan 3 times. Also it started developing cracks where the tanks meet the core. Not sure why, my only guess is after being mounted directly to the cylinder head for 5+ years the vibrations finally got it. Cross Country did change the design a bit and hopefully they addressed the issue & maybe they're using brushless vans now but you'd have to ask them. So with replacing the fans @ $100ish a piece & now the cracks I figured it's time to move on.

A few days ago I order a PDI front mount and am urgently awaiting its arrival. They do make a kit for the 78 as well:
Landcruiser VDJ 76/78/79 Series Front Mount Intercooler Kits

 

[mudgudgeon]

@mudgudgeon I have read trough quite a bit of The official 1HDT Intercooler thread. A lot of interesting stuff there. But one thing I was wondering, why do you install the fan under the IC, on a top mount. If heat is a problem, wouldn’t it be better to have it on top?

Then the fan could be inside the cut-out, allowing for a higher IC.

Electric fans are generally better at pushing than pulling.
Don't really know why, and not sure it's still true.


PDI make a nice looking kit