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mountainman
08-10-2009, 12:59 PM
My I get this forum's opinion on electric cooling fans for a tr3?
What size?
Mounted in front or back?
Do you still use the old fan also?
What is the best way to wire them up?
Thanks
Greg

martx-5
08-10-2009, 01:24 PM
A 12" fan will fit nicely. If you keep the original engine driven fan (which is up to you), you will have to mount the fan in front of the radiator. I personally don't see much of an advantage whether it's mounted in the front or the back. The fan kits usually come with all of the electrical goodies such as relays and thermo switches. It would be best to also add in an overide switch in the cockpit so you can turn the fan on whenever you want.

newmexTR3
08-10-2009, 01:25 PM
My set up, which I've been very happy with:

Puller mounted on back.

Remove old fan.

Use a good relay. Mine turns on automatically at a certain temp via a bung in the radiator.

I believe mine is an 11" or 12" SPAL: https://www.spalusa.com/store

You could call Scott at Wizard Cooling to see what fan they include with their aluminum radiators for the exact model: https://www.wizardcooling.com/

Cheers,
Gavin

tinman58
08-10-2009, 04:54 PM
I agree with Gavin
I am going to install a 12" puller fan and remove the stock fan. With a puller fan you are not blocking any of the radiator fins. Plus you might get a little more horse power without the stock fan!
I had a TR6 yellow fan that worked good, but in Brentwood it is 104 today and the more cooling the better.

TR3driver
08-10-2009, 08:42 PM
IMO, mounting a fan in front of the radiator will interfere with the airflow, and hence reduce cooling at higher speeds (when the fan should not be necessary).

I removed the original fan and it's extension, mounted the biggest fan that would fit as a puller. Mine did not come with any wiring and somehow I never did quite get around to making my custom fan controller work. But DeRale offers (in the US) a nice adjustable controller kit with a sensor that just pushes into the radiator fins; which is probably what I will use next time.
https://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=390077697908

Don't forget to consider where the power for that fan will come from. My stock generator has a hard time just keeping up with the headlights, and my fan drew more current than the headlights did. My 3A had a 60 amp alternator, so no worries, but I'm not sure I'd rely on the wimpy stock generator in hot weather and/or extended stop-n-go traffic.

newmexTR3
08-10-2009, 09:00 PM
Don't forget to consider where the power for that fan will come from. My stock generator has a hard time just keeping up with the headlights, and my fan drew more current than the headlights did. My 3A had a 60 amp alternator, so no worries, but I'm not sure I'd rely on the wimpy stock generator in hot weather and/or extended stop-n-go traffic.

Randall is correct- this has been an issue at times for me. After a good 4 hours of stop & go traffic on Long Island over the course of a day + headlights for 2 of those hours, and the electric fan on for a good amount of that time, the next day my battery was dead.

In lieu of installing an alternator, which I may do in the future, I bought one of those battery tenders (https://www.batterytender.com/) and just use that regularly, which seems to alleviate the issue, as well as keeping the battery in good shape!

Cheers,
Gavin

Don Elliott
08-10-2009, 09:05 PM
I installed a 12" Kenlowe fan with 10 shrouded blades I bought in 1991 in England while there on a business trip. I use it as a pusher fan. It is mounted in front of the rad, high enough to still permit me to use the hand crank. I wanted to keep the look of my early 1958 TR3A as "original" looking as possible for the judges so I still have and use the original fan which, I have heard, is essential at a dampener to prevent your crankshaft from breaking.

I had to trim a semi-circle in the cardboard air deflector above the centerline of the fan. This air deflector surrounds the rad to direct all the air flow through the fins. This semi-circle I cut is for clearance so the fan blades don't stick, drag or scuff on the cardboard air deflector.

I made the supports for the fan and these are secured to the side frame of the radiator.

I haven't noticed any overheating when I driving faster than 30 MPH but if I stop for five minutes, it starts to heat up quite quickly and so I flip on the fan manually with a switch just under the dash (almost out of sight) through a relay because the fan draws about 25 amps to get it started. Then the needle on the ammeter steadies out at about - 10 amps. The fan can drop the temperature on the Temp Gauge from 215 deg. F to 185 deg. F in about 3 minutes. Then when I get going again, I flip off the fan.

Don Elliott
08-10-2009, 09:06 PM
This is how I trimmed the cardboard air deflector.

PS - I run the standard generator with no problems.