Thread: Replacing viscous fan with Thermo??

Originally Posted by twitchy

Has anyone changed the viscous fan on a V8 for a Thermo only??
If so what brand & size did you use????
I was thinking of about 16" fan should be o.k.

IDEAS??????????????

Short answer, don't! When needed the viscous shifts heaps of air, when not it freewheels. Replace a viscous with a new viscous if the old one's worn, its there to provide massive airflow when you are doing it tough. Electrics will save very little fuel over a working viscous and are rarely enough for a 4WD.

I did that.
For a short time.
For a very short time.

If you do, I look forward to reading about your experiences. Your many experiences.

A word of advice, If you do change the viscous fan for a thermo only, don't take it anywhere near traffic, the bush, red lights, crossings or anywhere in summer, spring or autumn.

Winter in the driveway should be ok provided you don't let it run for long.

regards
Mick

I know of a few people who have put au falcon fans in and that worked ok. If you're going to do it use a 2 fan setup. Also add a switch that lets you turn them off when traversing deep water. The best setup, assuming this is the 3.9/4.0l v8 is to use thermos out of a range rover, properly done they will work just as well as a viscous. I still have a viscous in my disco and i hate it. Nearly every 4wd trip it either siezes or gets loose, simply because i can't turn it off! Anyway, double fans preferably from a rangie and make sure its done properly.

What other sorts can be used because I don't have a spare $400+ at the moment......... Know of a lot of people in Pootrols & landbruisers that have the AU twin fan set ups running fine......

The reason IMHO as to why thermo's have a bad rap is because people fit the fans you buy in auto part shops,they are A/C condensor fans not rad fans.Fit AU falcon fans,they will work just as good as the original fan and they do make a difference,I remember Larry Perkins saying it's worth 12hp in a holden V8. Pat

Originally Posted by PAT303

The reason IMHO as to why thermo's have a bad rap is because people fit the fans you buy in auto part shops,they are A/C condensor fans not rad fans.Fit AU falcon fans,they will work just as good as the original fan and they do make a difference,I remember Larry Perkins saying it's worth 12hp in a holden V8. Pat

Pat's right. There are plenty of threads on this topic, do a search.

Genuine fake EL thermos are in my POS and have no trouble keeping a 350 cool with a standard RRC radiator.

Come in a shroud and were about $200 new all up from Corio Auto Parts. One of the best things I did with this car.

With thermos you have the advantage of maximum cooling capability without road or engine speed, i.e. when slogging around in traffic or the scrub.

cheers, DL

Originally Posted by 350RRC

Genuine fake EL thermos are in my POS and have no trouble keeping a 350 cool with a standard RRC radiator.

Come in a shroud and were about $200 new all up from Corio Auto Parts. One of the best things I did with this car.

I agree .... BUT .... Just make sure your Alternator is upgraded to 110 AMPs .. or your find yourself stuck in a parking lot with a drained battery ...


BUT .... The Viscous fan is fool proof tho ...
..... as the thermos part is easy, but the temp switch method can be tricky

Mike

Originally Posted by mike 90 RR

I agree .... BUT .... Just make sure your Alternator is upgraded to 110 AMPs .. or your find yourself stuck in a parking lot with a drained battery ...

Mike

Doubt it, I've set plenty up in 60-70A alternator equipped vehicles

Falcon fans are great, nice fit, work well, excellent shrouding

Anyone who has had huge trouble with fans have either used crap fans, crap shrouding or crap controls