Thread: Thermo Fan vs Viscous Fan v6.023.455

I thought EL Falcon fans fitted early RRC radiators - the fans are too wide.

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Originally Posted by 101RRS

I thought EL Falcon fans fitted early RRC radiators - the fans are too wide.

IMG_20191122_130222.jpg

that's one small radiator ... time to upgrade it to a larger capacity unit!

The radiator works fine - it is a genuine early RRC radiator (out of a 101).

I'm looking at doing the electric fan conversion soon. Thinking about BA fans with either of these controllers Davies Craig Digital Thermatic(R) Fan Switch (12V & 24V) (0444) or Mishimoto MMFAN-CNTL-U Adjustable Fan Controller Kit

Originally Posted by Chivalry

I'm looking at doing the electric fan conversion soon. Thinking about BA fans with either of these controllers Davies Craig Digital Thermatic(R) Fan Switch (12V & 24V) (0444) or Mishimoto MMFAN-CNTL-U Adjustable Fan Controller Kit

Why complicate things... wire those suckers like 350RRC suggests.... You can wire high/low speed if you want slow speed ... just by using 3 relays. this is what I've done. its more wiring connections and complication to fail (but a huge number of manufacturers have the fans wired this way).



I just used a temp switch from a parts car in my backyard.

seeya
Shane L.

Just did this fan conversion on my 91 RRC a couple of weeks ago and have been testing temps etc. I have an older TM2 (from the old D1) which gives me fairly accurate metal readings, when compared to the readings from a laser temp gauge. Interesting that the coolant temps can be up to 10 degrees hotter than the surrounding metal - I checked this after the temp switch I bought was cutting in about 81º as indicated on the TM2, but I found on the laser gauge the metal at the rad inlet was dead on 90º. (FYI. The TM2 temp sender is on the hottest bit of engine I could easily find on the top of the engine, which is the front bolt of the inlet manifold, this was about 5º hotter than the top thermostat housing bolt).

After some research here on the forum, and now I've lost the link - but another member (thanks and apologies for not directly acknowledging) chose to run the Falcon fans from the original AC circuit, powering the new fans from the old AC fan wiring, and temp controlling from the override switch on the thermostat housing - seemed to make the most logical sense. I decided to go the same route, but as the old fans only seem to have a 20amp circuit total, used the AC fan power only as switches for 2 x 70amp relays - temp control was via a new 90º on and 85º off Tridon switch replacing the old one on the thermostat housing - nice thing about this is the fans also work when AC is turned on and you are not doubling the power draw by running 2 sets of fans.

i was driving in traffic today with AC on, 30º ish outside, and engine temps were very stable - 81 to 85 on the TM2 - meaning low 90's in coolant probably - didn't get out to check. AC blew cool with the Falcon fans only, they sure move a lot of air. I'm sure others would be more scientific about this but I'm working with what I have.

For power setup, as mentioned, the fans run through 2 x 70 amp relays (at Jaycar the choices were 30 or 70 so I went up), for fuses I used the engine bay fuse box from my old donor D1 - which has big screw down fusible links - with this I could run a big single primary wire to the fuse box, and short wires to the relays mounted on the support I made for the box in the engine bay. While I was at it I installed the ARB compressor I had and fused and relayed it the same way.

As mentioned I got a new 90 on / 85 off temp switch from Burson's which was a direct fit. Confirmed yes it does switch on a 90 coolant temp.

Fans: whatever can you find at a wrecker where the guy points to the old Falcon area and says go for it, fans and shroud with plug cost me $70. Not having a clue what I was looking for - from this forum I was looking for AU, all I could find were EA apparently, which after all turned out to be a reasonable fit. I cut of the long mounting arms, filled in some side gaps with alum angle, and clearanced for the bottom hose. Fortunately I had an old rad I could use for pre fitting (which as it turned out was 10mm shorter than mine but still worked out OK).

As I said at the start of this, setup seems to be quite stable, the power use is of some concern. The 91 currently has an old alternator from an earlier RR which I think is 65amp, (the original 80 amp one on mine after barn sitting for years, the nut terminals siezed and sheared off, so the the 65 was a stopgap from the 88 RRC donor). A new 100amp unit will be going in soon which should be enough. (Yes I kow there are Bosch conversion options but I can't be bothered right now, enough else to do).

Some photos are attached.

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Thanks Spel! Was there a part number for the Tridon switch? I've got 3 viscous fans here, I confirmed with Rovergauge that one of them is making the coolant hit 98 degrees on a short but fast drive, the other is slightly better but still has the AC fans kicking in after sitting stationary for too long, the other is rock solid and howls like a banshee who stepped on Lego but keeps temps at 88 degrees no matter what.

The noise from this fan is driving me crazy, it's even louder than the 500somethingwatt stereo I have in the car.

Originally Posted by Spel1

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As I said at the start of this, setup seems to be quite stable, the power use is of some concern. The 91 currently has an old alternator from an earlier RR which I think is 65amp, (the original 80 amp one on mine after barn sitting for years, the nut terminals siezed and sheared off, so the the 65 was a stopgap from the 88 RRC donor). A new 100amp unit will be going in soon which should be enough. (Yes I kow there are Bosch conversion options but I can't be bothered right now, enough else to do).

Some photos are attached.

IMG_2539.jpgIMG_2554.jpgIMG_2555.jpgIMG_2556.jpg

The alternator in my POS is only 55amp and I've never had a problem.

DL