Outer Limits 4x4 Board

hi guys

my cruiser has a 350 and i took it on the beach for the first time today, average weather maybe 30 degrees i have the standard 4.2 deisel radiator in there but she overheated after about 5 min of going resonably hard in softish sand. of the offrading i have done so far which is a lot slower in the hills it has been fine in terms of temp. now i want to know how good is a stock cruiser radiator? and what radiators do other people use for similar motors? i reallywant something that will keep it very cool cos i cant stand overheating so i want to be able to thrash it good and not worry about the temp!

are the 75 radiators the same size as 80 radiators?

I have a LS1 in my cruiser and use the std 80 radiator and its never over heated, a mate has a 350 in his 80 and uses the std rad also and his never heats up either...

Are u using an engine driven fan? or thermos?

it has a thermo fan on it, i think thats pretty good it pushes a fair bit of air and its hooked up to a temp switch so goes on and off automatically

350HJ75 wrote:it has a thermo fan on it, i think thats pretty good it pushes a fair bit of air and its hooked up to a temp switch so goes on and off automatically

id be putting a real fan on it.. thermos are never as good as engine driven fans.

I have a skyline with a turbo rb25 in it.. could never keep in cool.. threw the thermo in the bin and put a proper fan on it, and now the gauge never moves!

crankycruiser wrote:

350HJ75 wrote:it has a thermo fan on it, i think thats pretty good it pushes a fair bit of air and its hooked up to a temp switch so goes on and off automatically

id be putting a real fan on it.. thermos are never as good as engine driven fans.

I have a skyline with a turbo rb25 in it.. could never keep in cool.. threw the thermo in the bin and put a proper fan on it, and now the gauge never moves!

Not completly true just have to use the right thermo. LS1s in the commodore are cooled by thermo fans with no dramas. The twin fans from an AU are awesome, they flow around 3000cfm

The commo ones don't like mud though! killed mine

When i had the 350 in my cruiser with the standard radiator it got hot on the beach, the viscous fan was stuffed so i locked it so it would spin at engine speed with fencing wire, after that it stayed cool as.
Point being that the std radiator has enough volume and surface area, you just need to get the air through it effectively.

Matt_85Lux wrote:

crankycruiser wrote:

350HJ75 wrote:it has a thermo fan on it, i think thats pretty good it pushes a fair bit of air and its hooked up to a temp switch so goes on and off automatically

id be putting a real fan on it.. thermos are never as good as engine driven fans.

I have a skyline with a turbo rb25 in it.. could never keep in cool.. threw the thermo in the bin and put a proper fan on it, and now the gauge never moves!

Not completly true just have to use the right thermo. LS1s in the commodore are cooled by thermo fans with no dramas. The twin fans from an AU are awesome, they flow around 3000cfm

for the price of a good thermo u can put a viscous fan on which will still work better than the thermo

also get a temp gauge - the standard ones only relate to the standard motor and overheating might not actually mean anything on the chev

i do have an aftermarket temp gauge, normally it sits around 80 degrees C and can get up to 100 if im working it but on the beach it was up to 120 in no time. so a good fan makes a big difference? im not sure how good mine is i guess.

Good fan makes a HUUUGE difference, especially when you're revving hard but moving slowly.

I would look at everything but the radiator to start with, the best (electric) fans are not aftermarket new fans but used OEM fans from good cars.

I agree with others if you have room for a viscous fan put one on, you will improve cooling out of site. Make sure you add a suitable shroud as well though.

http://cgi.ebay.com.au/Zirgo-16-3000-CF ... 3358e15598

Try one of these.

Cris

ok cheers guys, im thinking i will stick with thermo as i have a gilore belt and i like it the way it is. and i like being able to temp control the thermo and such. so i will try a good thermo and good shroud, currently its not the best and see how i go

If you mount the electric fan in front of the rad you don't need a shroud.

If you mount it behind you need a shroud. In theory, behind is a little better, in practice I would just put it in front, no shroud, unless you have plenty of room and can find a shroud that fits well straight off.

ok so i went to rad shop in town and the first thing he spotted was the inlet and outlet of the rad are on the same side. so im getting those switched today and rad flushed so i actually use my whole radiator, and my thermo is pretty lame apparently so he reccomended getting something with at least 3000l/min or 106cfm. and most good aftertmarkets are around 3000 plus cfm so i think that will be sufficient.

tried all sorts of fans with shrouds to keep the 350 cool in a 40series.
Fixed fan was best, hard to find a decent rebuildable viscous hub for the chevs. Eventually got alloy crossflow radiator which is bigger and conducts heat better than original radiators.
THis rule of thumb seems to work: you need 1sq inch radiator frontage per cubic inch of engine displacement + 30% extra.
you might be right with a stock radiator if you are not going to drive it when temps get above 35C

vraamm wrote:THis rule of thumb seems to work: you need 1sq inch radiator frontage per cubic inch of engine displacement + 30% extra.

I find 1.3 square inches of radiator frontage per cubic inch of engine displacement is MUCH more effective.

chimpboy wrote:

vraamm wrote:THis rule of thumb seems to work: you need 1sq inch radiator frontage per cubic inch of engine displacement + 30% extra.

I find 1.3 square inches of radiator frontage per cubic inch of engine displacement is MUCH more effective.

You are a NASTY chimp!! Back in your cage for unnecessary SARCASM!!


But seriously, fan shrouds can assist also if you go the engine driven option.

ok so my radiator is 540mm x 500mm which equals 418.5 inches squared and my engine plus 30% is 455 inches squared, so my radiator is 91% big enough which is not too bad according to that rule of thumb. plus its a 4 core. it looks like ill go a clutch fan as its A, what everyone says works best and B, the cheapest option. all i need to do is make my own fan shroud for it and if that dont work put a thermo in front of the rad.