Outer Limits 4x4 Board

Hi, I have just put a 350 Chev into an 84 4Runner. Goes great but I am having troubles keeping it cool. I have a three core radiator, twin thermos and the viscous fan running. At 100 - 110kph on the highway after an hour or so it seems to heat up to 210 degrees farenheit. Any suggestions as to what may help? I dont have shroud at present but I am trying to find one that will fit. Thanks

Harold.

had a 350 in my old 4runner

not probs with heat

run a shroud , and a decent fan.....no coupled fan
try an find the plastic type with 6-7 blades i think it is
they have some resistance up around the 6000rpm or so , but other than that , theyre the best to keep somethin cool

i had thermo's as back up

but an engine fan is the best at keeping somethin cool

Silly questions, but very important things to check:

Is the gauge a good brand, or a cheapy?

How much crap is in front of the radiator?
Sometimes electric fans in the front can actually restrict airflow at speed.
Maybe take everything off and go for a run to see what happens.

Has the carby (I assume) been correctly set up and jetted for this engine?

Have you put in a new thermostat?

Has the radiator been cleaned out?

Is the timing adjusted correctly?

Did you put a new exhaust on?
Connecting up the original can effectivly prevent the engine from breathing properly.

All of these can make the engine overheat.
I've never been a fan of the fixed non-clutch type fans, as they don't 'cut off' at revs and allow the flow from the speed of the car to cool the engine.

If these don't fix it then you can go back to the more expensive option of a larger radiator.

try the above .
but what u can try is putting bonnet scoop that faces backwards .
to let air out .
if u want more air to flow threw the radiator , this will help .
but before u cut a hole out of the bonnet .
remove the bonnet and go for a drive .
in winter you windscreen won't fog up as much , because of the warm air from the motor ........
and another thing i have done is lift the rear of the bonnet up 10mm to let air out .....(5mm might work)
i made a custom fibreglass bonnet for my cruiser . with air ducting.....
let me know if u require any more info ....

I hade a 383 SBC in my gen 1 hilux years ago with a 4 core HJ75 radiator fitted engine, fixed eng driven fan, and a cowling (most important) i have since used on my 80Ute and some other 4B's with cooling issues the Bennet Ecotherm Cooling system equipment which works real well. This is the link to the Members section on the working principles of the system. http://www.outerlimits4x4.com/PHP_Modul ... hp?t=13466
Wally

Another obvious check would be to make sure the power has been applied to the electric fans the right way. If you have used the bog standard wiring harness it may be set up for suck through, meaning that it is blowing air out the front of the vehicle if you mount the fan in front of the radiator. At speed the airflow going out vs. the natural airflow going in would cancel each other, resulting in a net zero airlflow through the radiator and your overheating problems......

The viscous fan will cut out at speed.

the viscus fan willnot cut out at speed
the fan was designed to let the engine rev more freely by alowing the fan to slip when engine reved the fan than would catch up to the engine revs down the trac
that is why its called a viscus because it allows slip

rock hopper wrote:try the above .
but what u can try is putting bonnet scoop that faces backwards .
to let air out .
if u want more air to flow threw the radiator , this will help .
but before u cut a hole out of the bonnet .
remove the bonnet and go for a drive .
in winter you windscreen won't fog up as much , because of the warm air from the motor ........
and another thing i have done is lift the rear of the bonnet up 10mm to let air out .....(5mm might work)
i made a custom fibreglass bonnet for my cruiser . with air ducting.....
let me know if u require any more info ....

Check with rego authorities first about these mods. Rearward facing scoops open into the engine bay are generally illegal due to the possibility of coolant/oil getting onto the windscreen.

Spacing the rear of the bonnett up is effective but makes for a head removal device in an accident, also illegal in most states as far as I know.

Cheers
Daryl

derangedrover wrote:

rock hopper wrote:try the above .
but what u can try is putting bonnet scoop that faces backwards .
to let air out .
if u want more air to flow threw the radiator , this will help .
but before u cut a hole out of the bonnet .
remove the bonnet and go for a drive .
in winter you windscreen won't fog up as much , because of the warm air from the motor ........
and another thing i have done is lift the rear of the bonnet up 10mm to let air out .....(5mm might work)
i made a custom fibreglass bonnet for my cruiser . with air ducting.....
let me know if u require any more info ....

Check with rego authorities first about these mods. Rearward facing scoops open into the engine bay are generally illegal due to the possibility of coolant/oil getting onto the windscreen.

Spacing the rear of the bonnett up is effective but makes for a head removal device in an accident, also illegal in most states as far as I know.

Cheers
Daryl

i doubt 10 mm will change the decapitation ratio by anything. if you hit something hard enough for the bonnet to cut the A pillars and cut your head off, i think you would of died from other causes anyway.

383FJ45 wrote:

derangedrover wrote:

rock hopper wrote:try the above .
but what u can try is putting bonnet scoop that faces backwards .
to let air out .
if u want more air to flow threw the radiator , this will help .
but before u cut a hole out of the bonnet .
remove the bonnet and go for a drive .
in winter you windscreen won't fog up as much , because of the warm air from the motor ........
and another thing i have done is lift the rear of the bonnet up 10mm to let air out .....(5mm might work)
i made a custom fibreglass bonnet for my cruiser . with air ducting.....
let me know if u require any more info ....

Check with rego authorities first about these mods. Rearward facing scoops open into the engine bay are generally illegal due to the possibility of coolant/oil getting onto the windscreen.

Spacing the rear of the bonnett up is effective but makes for a head removal device in an accident, also illegal in most states as far as I know.

Cheers
Daryl

i doubt 10 mm will change the decapitation ratio by anything. if you hit something hard enough for the bonnet to cut the A pillars and cut your head off, i think you would of died from other causes anyway.

Maybe, but Mr Plod is still gunna give you a rocket if he notices.

derangedrover wrote:

383FJ45 wrote:

derangedrover wrote:

rock hopper wrote:try the above .
but what u can try is putting bonnet scoop that faces backwards .
to let air out .
if u want more air to flow threw the radiator , this will help .
but before u cut a hole out of the bonnet .
remove the bonnet and go for a drive .
in winter you windscreen won't fog up as much , because of the warm air from the motor ........
and another thing i have done is lift the rear of the bonnet up 10mm to let air out .....(5mm might work)
i made a custom fibreglass bonnet for my cruiser . with air ducting.....
let me know if u require any more info ....

Check with rego authorities first about these mods. Rearward facing scoops open into the engine bay are generally illegal due to the possibility of coolant/oil getting onto the windscreen.

Spacing the rear of the bonnett up is effective but makes for a head removal device in an accident, also illegal in most states as far as I know.

Cheers
Daryl

i doubt 10 mm will change the decapitation ratio by anything. if you hit something hard enough for the bonnet to cut the A pillars and cut your head off, i think you would of died from other causes anyway.

Maybe, but Mr Plod is still gunna give you a rocket if he notices.

yeah, wasnt saying it isnt illegal. just that its extremely unlikely to cause injury.