Cheers Tex, You will know the fans, they are the twin AU Falcon fans, car also has a new 950cca battery and a 140 amp alt, we will keep at it.

No thermostat, belt driven clutch fan, '65 radiator.

Oh ok Al . They are normally good .
No mechanical fan with an electric waterpump
Like I noted check air flow out of engine bay . Do you have a scoop ?
I have seen cars in the shop with aftermarket electric fan shrouds to have airflow reduction . That is why some euro cars have flaps on the shroud , lets plenty of airflow at speed .
If the car is idling bonnet shut from cold does it quickly or slowly build up heat ? ie does it take 5 mins or so to get to 200F or 15-20 mins ? or longer ?

Tex

Probably only 5 mins to get to 200 yesterday but as I said it was a hot/humid day at 35 !!

No scoop at the moment, just a hole thats too big for air cleaner

5 mins to 200F is way too quick . even on a 35deg day . mine takes a lot longer than that .
run a probe in top tank to confirm temp .
hole in bonnet will let hot air out , can you feel any air flow with fans operating ?
I know its a pain but can you fit a mechanical waterpump to try ?


Tex

sounds like you have a flow issue still.. either
the radiator is too small or is plugging up..
a good radiator will run fine on the street at
50mph without a fan(has enough air flow)

Sorry Tex the 5 min to get to 200 was driving not sitting idling,
Yes with the fans, if you put your hand in front of the radiator you can feel heaps of air pulling through.
I will double check the gauge.
Not an easy thing to change over to standard water pump but I do have an Ali one somewhere.

Even driving that is too fast . Feel air flow past air cleaner out from under bonnet .
You will have to make sure radiator is fully clear , testing with a hose wont show much even if half blocked . Water will flow where it can .
Are these items previously used and ok then ?
You may even have to check waterpump flow rate .
Also check actual voltage at pump and fan . Seems less likely fan is faulty if it keeps heating up at road speed above 50klm hour

Tex

I agree

Tex

UPDATE.......

Car has done around 400 mile now and we are still running totally open.
Big change was dumping the coolant, flushing and filling with water and one bottle of Redline Water Wetter, it dropped 20 !!!!!!
FIXED

nice result . I must say I use Water Wetter and race additive - no glycol but rust inhibiter . No anti freeze/anti boil

Tex

The minute the air temperature in my yard is 180° I'll take the thermostat out. Unless you live on a volcano that's not happening.
Until then, all running w/o a t-stat does is pollute the oil, increase sulfuric acid content, increase ring wear, and wash down the walls with rich mixture.

Polyspheric, Do you understand that we have been trying to get the temp DOWN to 180-190 ? Yes I know that a cold engine is not good and would never beat on it until the temp is up.
Now we will look at controlling the temp with the thermo fans.

If you had a overheating issue they say that Water Wetter works best with straight water, no other coolants .

Yes , but , i also want an inhibiter in the system . Its not coolant.
Glad its worked out .
PS , i have not run a tstat for years . As my cars are dailys plus strip . I can live with it taking a little longer to warm up , i am concerned about not getting up to temp and pulling high rpm with tstat not open at track
A long time ago a radiator repairer/builder told me here in Sydney , like Perth , its not so hot or so cold we really need anti freeze or anti boil additives

Tex

So a long warm up is a good thing?
The thermostat is not your problem.

Yep. A long warm is a killer.

As poly says, the thermostat is not your problem.

You didn't actually sort out your cooling issue. You just threw everything at the wall and hoped it fixed it.

Make it run with a thermostat and your engine will thank you.

Dont forget I have an electric water pump and electric fans so I can leave them OFF during warm up, probably warm it up quicker than a thermostat .

FWIW. Indy headed 540, Meziere remote pump, no thermostat, no restrictor, 26" alum. radiator, shrouded puller fan. Street driven.
On hot days it ran 210-215. After installing a remote fan type transmission cooler, it now runs 190-195. Removing that heat source from in front of the radiator made that much of a difference.

I had an electric pump and fan on the street and the car would run cool around town but would climb to about 220 as soon as I got on the highway.
Now being a tech for over 30 years told me it was a flow issue,air and or water through the rad. I took the electric pump and fan out and installed a belt drive pump and 1 to 1 pulleys with a 5 blade viscous drive and viola!!! 180 degrees on the highway. Now thats with a 180 stat and a simple factory type deal with no shroud even.

Gus