Measuring radiator cooling efficiency

[SpenserAK]

If only full aluminum rads were more common and not so many dollars. I believe in engineered plastics, but would be all over that!

 

[Dave 2000]

I cannot read all of the thread however, if the AC radiator is clogged or the gap between the AC and engine cooling radiator that could be the issue, there is something else to note and has been proven. At speed when the engine is working, you would think that the air flow through the two radiators would be sufficient to cool the engine, this is NOT true. Your viscous fan should engage at higher speeds. I know this goes against conventional understanding and thinking but I have proved it, so somthing else to look at.

Regards

Dave

 

[nukegoat]

This isn't this hard as this forum makes it out to be. Optimum cooling is:

* remove thermostat entirely. No thermostat means MAXIMUM FLOW and no parts to break.
* Replace silicone in fan clutch with jbweld.
* Pack crank pulley with jbweld to increase OD, thus overdriving the water pump and alternator
* Drill large holes in hood

 

[gummycarbs]

Your viscous fan should engage at higher speeds. I know this goes against conventional understanding and thinking but I have proved it

How did you prove it and where can I read about it?

 

[NCFJ]

I use Ron Davis Racing radiators in the trucks I build. I use them simply because they work and are all welded. Also because I don't have to worry about anything going wrong with them. Its been my experience in both 60 and 80 series that an LS3 with twin Spal fans stop running past 35-40MPH. Temps stay right in the 190-195 range. Make sure you run a ground to the radiator.
Yes they are expensive, without a doubt a case of you get what you pay for.

 

[Dave 2000]

How did you prove it and where can I read about it?

I have been an advocate of electric cooling fans for more years than I can remember, certainly back to the 80's, despite opposition I have proved they work IF DONE PROPERLY and are more efficient than the mechanical offering.

My present 80 has a PWM fan from Mercedes, and I am VERY careful and particular with my testing. I have a light that comes on when the variable speed fan is running at slow speeds and when it is running at half speed to cover the AC when going slow or in traffic.

General driving around and at any speed up to about 70 MPH the fan is off, go over this speed for around five or six minutes and the fan comes on, the dashboard gauge reflects this (modified gauge so actually does move as temperature increases), so there is proof enough. To add to this I had a highly modified XJ 5.3 C, this too had twin electric fans and the same thing, run the car at around 80 MPH and the fans were off, sustained speeds high and the fans would come on.

You can find all the information in my long running thread: Builds - My LC 80 thread. - https://forum.ih8mud.com/threads/my-lc-80-thread.365673/

Here you will find where I used the 4.6 Lincoln two speed fan, it was a second hand unit used for testing, trying to get a new one from the states is harder than you think as they went to PWM versions, and there was also single speed versions adding to the confusion, throw in the manufacturing went to to Mexico.....nuff said.

Before fitting the Mercedes unit I did plenty of testing, this is all documented in my thread, being a little picky about accuracy.....(no make that really picky) with testing I even used two thermometers!

Feel free to read through, the PWM fan easily cooled the 80 in 40* C here in Spain even with AC on, and FWIW it has never had to go to full speed.

Regards

Dave

 

[Saito]

^^^^yup^^^^
@Dave 2000 , this is my experience with electric fans as well. Mine are set up to run from 60% to 100% across a 10° span and runs at 100% when the AC is on. It sits idle on the highway as air flow through is obviously sufficient at speed. It’s worked very well for me and I’m happy. Also super easy to remove and the SC belt is easily accessible as well.

 

[Dave 2000]

The good thing about the Mercedes fan is it is sealed, I am sure this was the reason for the demise of the Lincoln fan, being submerged when crossing 'Rambla's'. To be honest I have not had much luck with SPAL fans, and are certainly not up to snuff in the 40+ heat we get here. The Mercedes one is the same diameter, blade count and pitch as the OE fan, and using it's original mount is almost a perfect fit to the 80 rad. FWIW I do keep the old mechanical fan with me when going off road, the old mechanical fan has kept me company for years, yet to need it but you never know.

It's good to hear of someone who has 'seen the light', I love hearing from people who don't quite get how a DC fan works, they think it is like a light bulb, along come equations of them needing hundreds of horsepower to drive the alternator and such BS.

Regards

Dave

 

[Bambusiero]

any replacement radiator will likely be another copper/brass one because I just don't trust plastic;

Allow me to gently suggest...
Your apprehensions about plastic radiator tanks, having shared that feeling, and, as a result, having suffered through two years of un-nessesary frustration, limping by with an (almost) non-functional cooling system - here in the hellishly hot desert southwest US... are completely unfounded.
Look around you - every modern car, from every manufacturer... Plastic tank / aluminum core radiators - running literally all over the world - for how many decades now?
Let's be practical - if you get one of the statistically unusual leakers - well then - shrug - order up a new one. They just aren't very expensive, and the replacement procedure isn't difficult or high skill.

p.s. This subject has been absolutely - - so many time over - here on this forum. Search (for my name, for one) and read from now until next week...

 

[Dave 2000]

Allow me to gently suggest...
Your apprehensions about plastic radiator tanks, having shared that feeling, and, as a result, having suffered through two years of un-nessesary frustration, limping by with an (almost) non-functional cooling system - here in the hellishly hot desert southwest US... are completely unfounded.
Look around you - every modern car, from every manufacturer... Plastic tank / aluminum core radiators - running literally all over the world - for how many decades now?
Let's be practical - if you get one of the statistically unusual leakers - well then - shrug - order up a new one. They just aren't very expensive, and the replacement procedure isn't difficult or high skill.

p.s. This subject has been absolutely - - so many time over - here on this forum. Search (for my name, for one) and read from now until next week...

I have to go with this too, when I brought my 80 to Spain circa 11 years ago the fins were all but gone in the radiator from corrosion and age, I picked up a replacement from a 'Joe Blogs' spares shop on the way in case the old one 'let go' over the 2000 mile trip, I did not have time to fit before I went. The old rad held up OK, the OE was plastic and aluminium, the replacement the same. Up until a couple of weeks it had looked good although the vehicle has not been used properly for a couple of years (Covid followed by brain surgery), and I noticed the top of the header tank was wet with antifreeze. I think I have to take the blame for that, being weak now on my right side I had thrown a heavy blanket over the front of the vehicle, this allowed me to lay across the radiator and of course the slam panel so as to not get stabbed by the safety hook while fitting sound deadening pads to the underside of the bonnet. Putting my weight on the radiator may well have damaged it?

Radiators are pressure vessels so the leak may 'heal' when the car is used properly again? I will probably end up replacing it if it leaks again, but to allay any fears, the aluminium/plastic radiators are fine and 'fit for purpose'.

Regards

Dave

 

[Dave 2000]

This isn't this hard as this forum makes it out to be. Optimum cooling is:

* remove thermostat entirely. No thermostat means MAXIMUM FLOW and no parts to break.

Good job your not posting that on a Chevy forum in the V8 section.

Regards

Dave