Australian 4WD Action – August 2019

FAN SHROUD REMOVED

A fan shroud is designed to make the fan pull air

through the whole core of the radiator, which increases

the cooling of the engine at slow speeds. At higher

speed, however, they can restrict airflow through the core

slightly, so proper shroud design is a must.

We know engine temps

were 89°c during our control

run with the shroud on, so

we whipped the shroud off to

see what difference it made.

Sure enough, engine temps

rose to 92°c - a difference of

3°c. Not a whole lot on its

own, but it’ll definitely

contribute to an overheating

problem if you’ve also got

issues in another area.

MUDDY RADIATOR

How

much

mud does

it take to clog your

radiator and shoot

temps through the

roof? It’s sort of

like asking ‘when

will they put the

price of diesel

up?’ - We know

it’ll happen, it’s

just a matter of

when.

There was only

one way to know

for sure, so in true 4WD Action style, we hit a few mud holes

to see what it did. After five minutes we stopped to see how

things were looking. The radiator was definitely half

blocked, and truth be told, we were as curious as anyone to

see how much of an effect a half blocked radiator would

have on things.

Sure enough, temps shot straight up to 98°c within just

meters. With no signs of slowing down, we stopped the test

straight away to avoid damaging the engine. It just goes to

show how five minutes of fun could kill your engine.

2

3

SPOTTIES AND CONTROL

BOX RELOCATED

The engine relies on airflow through the radiator to

keep things cool, so how much difference does fitting a pair of

spotties and a winch control box make? Could it really be that

much? With normal operating temps of 89°c already recorded,

we unbolted everything and

set off.

We were expecting temps

to drop, but we weren’t sure

by how much. The best it did

with both spotties and

control box removed was

87°c, a difference of just 2°c.

It’s something, but having

them fitted certainly isn’t

going to cause our 80 Series

to overheat.

HIGH-RANGE 3RD VS

LOW-RANGE 5TH

5th gear?

Our control run was done in low-range 5th gear, so we knew

temps were set at 89°c. As soon as we took off in high-range

we could feel the engine labouring. By the time we got to 3rd,

temps had peaked at 94°c, 5°c higher than in low-range.

Between gear selection and tyre pressures, we had two very

big contributors to overheating.

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