Thermal fan, engine fan or both? What's best?

[pfillery]

On a holden 186 conversion.

I'm thinking of swapping out the radiator for a narrower newer one fitted a little better (the thermal fitted currently uses pins through the core so has caused some damage) and it should allow room for an engine fan, if this is indeed the way to go. It seems that almost all vehicles from the 70's and before use an engine fan but I've heard 2 different schools of thought.

Any thoughts?

Also should the fan push air into the radiator from the front of the vehicle or suck it through? And for a thermal fan should it be touching the core or can it sit further back? May seem like silly questions however I've never wanted to stick my hands too close to find out.

[korg20000bc]

I've never used one but that doesn't stop me having an opinion:)
I believe that you can free up some horse power by removing the steel fan from the engine. Someone once told me that it acts like an engine govener.
I see thermal fans on stock vehicles positioned in front of the radiator and pushing air through so this should not be a problem. It just looks messier than behind.

The fan shroud should be as close to the radiator as possible to ensure that the fan is sucking or blowing the air through rather than any escaping around the sides.

[Homestar]

When I put a 202 in my series IIA many moons ago, I mounted a thermo fan in front of the rad mainly for clearance reasons - using an engine driven fan was a bit on the tight side, and it wouldn't have needed much for the rad to get chopped up. It worked a treat, and I never had overheating issues.

[debruiser]

PF,

Did you end up putting that fan in? could i get some details/price that it cost you? Save me thought on converting mine. :)

[Kime]

Hi Debruiser,

I put a thermal fan in my 202 powered series 3.

Haven't as yet removed the engine fan, as to scared just in case the thermal fan packs it in at some stage... Most likely won't, but never know...

Cost of fan was about 70 i think and then i had a go at installing, an something didn't go right...

So took it to my local auto leckie cost 100 to install.

Car never goes over 90 in normal driving conditions, the only time it goes over is when its either a REALLY hot day, when i got the ol girl loaded up, towing something, or doing more then 100 on the highway.

I do believe that once i change the diff ratios from 4.7's to 3.54's this will change my overall RPM at higher speeds so therefore bring the engine down to Normal range RPMs. Either do this or install a bigger radiator to handle higher RPM... Not keen on sucking through MORE fuel... :(

[debruiser]

Thanks Kime,

I've found that on the highway my series 3 goes fine (as far as temps go) it's when I slow down a little and make it work a bit in 2nd and 3rd that she gets hot.

After a more serious look at my radiator though I think that just purchasing a new one would work wonders as well.... i've got a 3 core i think, might even see if i can get a 4 core (i have room, it's a 6cyl originally)

[Kime]

yeah, see, i think i need to get mine checked out...

At low down revs, hard working, she is fine, around town, bumber to bumber traffic all perfect temps...

Its only when at high rpm she gets hot.. And heaven forbid if i put a load on or tow something on the highway, geez, she doesn't like that...

something else to look into :confused:

[jakeslouw]

"Its only when at high rpm she gets hot.. And heaven forbid if i put a load on or tow something on the highway, geez, she doesn't like that..."

Maybe have a look at the water pump impeller?

[debruiser]

"Its only when at high rpm she gets hot.. And heaven forbid if i put a load on or tow something on the highway, geez, she doesn't like that..."

Maybe have a look at the water pump impeller?

HAHA yea my old one had holes right through it..... made an interesting screaming noise cause the bearings where shot too. :)

Off the top of my head a new one is like $30.

[Kime]

Has me concerned now, was only about 4 months ago had a new water pump put on...

It made a MASSIVE difference with the new one, like i said, never gets hot around town, but yeah, just the high revs :(

[Chris72]

from memory the Ford twin fans are a common swap over for the holden motors not sure how they will fit in the Landie engine bay, with 1 fan hooked up to the temp sensor and the other wired to a switch on the dash for when things start to really warm up, I had a UC torana with this set up and it never got hot.

[mick88]

Biggest diameter electric fan you can fit in and fitted over the "hot spot"
Don't mount it with bolts going through the fins, make up some brackets..20 x 3 flat steel or 25 x 3 aluminium flat work well and are easy to bend into the required shape. Mount the fan as close as you can to the radiator so that it will force the air through the fins. My vehicle is a swb so my fan is on the outside.
I fitted a thermo switch (tridon brand) that cuts in at 88C and out at 83C into the thermostat housing, as well as fitting a manual override switch. A Holden motor usually would run a 180 (82C) thermostat but i run a 170 (77C) and it all seems to work well together. Make sure you run the thermo fan through a relay so that you are not overloading your ignition.
If you have a lwb that was a six cylinder I would be running an engine fan as well. Fit one with a viscous coupling and a fan shroud to drag the air through the radiator and you should not have any overheating issues.
You can't have too good a cooling system.

Cheers, Mick

[Series3 GT]

This is an interesting thread, cause I was wondering what setup to use when I end up putting in the 202 into my IIA. I've got a thermo fan and I don't think that I'd be able to fit the engine fan cause it's a 4cyl. I'd like to fit a thermatic switch as well so would this be a good option?

[Homestar]

This is an interesting thread, cause I was wondering what setup to use when I end up putting in the 202 into my IIA. I've got a thermo fan and I don't think that I'd be able to fit the engine fan cause it's a 4cyl. I'd like to fit a thermatic switch as well so would this be a good option?

Yep, that's the ticket. Did that on my IIA and never had issues. I just used one of those switches that you shove he sensor in the top rad hose - worked well.

[Series3 GT]

How big was your thermo fan? I've got a little 10 inch or something around that size fan that came off a Mazda used for the aircon radiator but seems to move a lot of air.

[Homestar]

Can't remember the size off the top of my head, but it was the biggest I could get in front of the radiator. It was an aftermarket version, as there weren't too many cars with thermo fans around when I did the conversion that would have had parts sitting at a wreckers.

I wasn't too much older than what you are now when I did up my first Landy.

That makes me feel a little old now I've said that....:D, but it was only 20 odd years ago...