cooling fan again!

[Pfreen]

Good choice.  That's what I use.  Also, the multi blade fans don't flow as well through a restriction, (like the radiator)

[Fotog]

More pressure = more flow for a given resistance (like the radiator).
...and more flow will require more current because it's doing more work (moving greater mass of air).  👍 It's all to be expected.

[jbcollier]

+1 on the fan with fewer but larger blades.  It's a 10" fan.  An 11" fan will fit as well.

[califkid_66]

the original fan pulls about 15 amps acording to my amp meter the spal 10 inch push 14 amps so it should be direct replacement using original relay and wiring

now a new question my temperature gage shows 95 i took the temperature in the swirl pot at idle it went up to 180 then the fan went on and temperature went down to 175 and pretty much stayed there
95 celcius is 203 fahrenheit 
one is the swirl pot temperature the real engine temperature im using a really good digital thermometer
second my temperature sender is close to the manifold could this affect the reading
three the fan went on exactly at 180 in the swirl pot witch leave me to believe the swirl pot temperature is the real temperature
please let me know what you guys think thanks again

[jbcollier]

Yours is a wedge head Renault engine IIRC.  The swirl pot is the output from the rad so it is the "coldest" water in the system.

[califkid_66]

that’s not what i wanted to hear !!
i went for a ride today and i thought
if the temperature in the swirl pot was
180 and gage is at 95 when i was in traffic it went up to 100
so i figured if 95 is equivalent to 180 then
100 celcius would be 189 witch would have been perfect
but if the swirl pot temperature is supposed to be cooler
then i was running at 95 celcius witch is 203 f and 100 celcius  in traffic witch is 212 f
witch is to hot

[jbcollier]

It's a pressurized system so 100C is not fatal by any means.  I've had mine up to 105C in traffic with the AC on (because I had a useless, slim rad fan).

So some questions:

What thermostat are you using?

You can get 71C/160F, 75C/168F, 80C/178F, 85C/180F, 88C/190F

71/160 works fine if you only drive in summer.  If you drive in cool weather (below 0C/32F) a better choice is a 75/168 or 80/178.

Are you using antifreeze?

Even in the sunshine belt, "antifreeze" is a good idea as it also raises the coolant's boiling point.

Rad has been cleaned or replaced?

Copper rads cool better at low air speeds.  Aluminium rads are much lighter and, surprisingly cheap now.  If you bought a new aluminium rad, make sure it isn't too thin and that it has a functioning baffle.

Rad fan?

We have discussed this ad naseum.  Whatever I said before, still goes.

[jbcollier]

Here's my readings for comparison.

Canada cold: coolant warms slowly and stays at thermostat setting

Cool: coolant runs at thermostat +5C

Normal: coolant runs between 80C and 90C with a 75C thermostat.  Fan comes on a slow speeds and quickly cools things back down.

Hot (35C+, AC on): coolant runs between 85C and 100C, Fan comes on a slow speeds and cools things back down slowly.  Turning off the AC makes a huge difference but the cabin heats up quickly!

[califkid_66]

thank for the quick reply
thermostat i put in a summer one not sure of the numbers
i am using red antifreeze the one for toyota
i did put a product to clean and flush the radiator last year
the temperature was always around 90 c
changes that happened i put in oil that was specifically manufactured for a garage that specializes in english cars as zinc in it after the oil change it was running around 85 c then going not passed 90 c
then i had my fan not working temperature went up but not over 100 c
i changed the bearings on the fan motor but could not get new brushes one side barely touching so i don’t know if it’s running at full power
one more question if in the swirl pot it’s the coldest what would be the difference in temperature before going in the rad
thank again ps im waiting on the spal fan and it’s the original radiator the cooling fins are hard so it’s in good condition

[jbcollier]

I think it would be a good idea to have the rad tested as iIt sounds like it is an original radiator.  The late 60s and early 70s were a long, long, long time ago.

[califkid_66]

sorry for the late response but i have been trying to join a lapping club and you have to follow a course and i was lucky enough to register on sunday but i told the instructor my car had overheating problems
he said try it do what you can so i went for it
we had to follow and instrutor and i was unbelievable how well it behaved acceleration braking after a couple laps we went out in the paddock only to return right away my temperature gage was staying at 90 but the second time went up to 100 engine ran great i left my original fan on the whole time it was 30 celcius and sunny
  afterwards when in the garage i got a laser thermometer and let the lotus idle for 15 minutes i took the temperature before the water pump 163 f and right after 185 f you can see in the pictures
and my gage was a bit over 90
   so i decided to do a radiator flush im almost done drained all the coolant filled with the cleaning product and water let it ran 20 minutes drained filled with water another 20 minutes now im waiting for cool down and gonna drain and put new antifreeze can’t wait to see if it made a difference  all the time i was doing the radiator flush the temperature stayed at 85 c at idle

[califkid_66]

went for a 24 miles ride after flushing the cooling system
and pushed it a bit the result in the picture stayed at that temperature the whole time

[jbcollier]

Glad the caustic solution helped.  I still would recommend taking it to a rad shop for a proper evaluation and rod-ing out.  Even rad shops use mechanical means first.  It's almost 60 years old after all.

[califkid_66]

i just watched a rod-ing video i had no idea that could be done thank for letting me know im gonna go get it done for sure thank again

[califkid_66]

Went back lapping went all out for 15 minutes the temperature never went over 90 after getting off the track I parked and the temperature was at 90 and the cooling fan did not even go on I’m still waiting on my electric fan but I think the rad is ok
 One question is the rad from a tc special  the same as the s2 Renault apart from the otter switch cause my friend gave me is parts car the rad is still in it I would send it for rebuild unless it would be better to get an aluminium rad since the prices are pretty low