OEM radiator?

[Helirich]

I've read that the OEM radiators are not good quality. The problem is the plastic end caps. I've had no problems with my cooling system, but it sounds like a problem I don't want. I just went down to measure the fans and noticed the ends on my radiator are made of metal. (Not plastic) Does that mean the PO allready changed it out? (I hope) Were any stock radiators all metal? If some stock radiators were metal, are they still bad for some reason?

That would be great news, but the fan motors definitely look to be old. They are very long. The shroud looks to be in good condition. I was going to replace the whole works, but if you guys confirm I have a good rad, all the better.

As best as I could measure, the fans were 10" across. Can someone confirm this? (It's kind of hard to measure) I really want to go to brushless fans.

[Helirich]

I thought I would copy and paste this from another site. I know the guy that wrote this and he knows his stuff. It's a long read, but worth it.

Compiling all the cooling tech into one thread. Not limited to just fans.

Brushless:
Brushless fans are taking over the OEM and aftermarket and they are starting to show up on the newer ULTRA4 builds. The most common right now is the brushless Spal fans and they are easy to tell from the motor design. The ones shown below are the GEN 2 motors. The older Gen 1 motors and controllers are discontinued as they have a different electrical signal system and do not interchange with GEN 2. The motors also look different.
The brushless fans also have all the new tech in the shroud and blade design compared to the older brushed versions. Some of them might look backwards as they are going towards a recessed/flush drop in shroud/fan style versus the traditional surface mount that sits up high. The deeper shroud design allows better air flow through the core. The deeper blade designs are also because they are more powerful and pull more pressure and it also makes them a quieter as the rpms are lower so the frequency is lower and less annoying.
The brushless fans are always connected to power and a third and fourth signal wire is used to turn the fans on. No external relays or controllers, everything is inside the motor. The signal can can be a constant on full rpm or a PWM signal to variable the rpm. The Spal temp sensor is a smart sensor that outputs a PWM signal with a percentage based on the predetermined temp range by the part number. If you dont use a sensor, one signal wire is grounded (-) and one is powered (+) and it doesn't need anything else to run.
When the fans start up they wiggle to find home and then slowly ramp up to the signaled speed. If you physically block the fan blade the controller will fault out and reset and try to power up again until the obstruction is removed. The fan also has overload protection and overheat protection. For instance mud or water, stick, or a bent shroud dragging on the blade. It can derate its power output to stay cool if things get too hot but at those temps your engine should be on fire. The sensor has a ramp so it starts out low say 25% and ramps up if the sensor temps are not dropping, so it only uses what power it needs to cool. One sensor can power multiple fans so they can all power up together and not have to stagger start them or have one pull air through the shroud if the other one is off.
Lastly is the run life of 30,000 hours at which 95% will keep going and 5% might fail. The brushless motors dont have brushes to wear out and are more efficient so they will outlast most any other moving part on a buggy. The other big part to life is that they are IP68 and IP6K9K so they keep water and dust out of the motor and controller.

Noise:
Noise pertains to both brushed and brushless. The small diameter thin blade designs are the worse for noise as they need to turn faster to make the same airflow as the deep curve blades, so their frequency goes up.

Blade and Guard Design:
This pertains to both brushed and brushless. Thin blades can not pull the same CFM with high restriction radiator cores. Free air yes, but load them up and they can not move the air like a thick blade. The thin blade guard designs don't handle the bottoming out and G force as well as the heavier built thick blade shrouds which have more support. That is why you will see CBR and others build metal support straps for the thin fans. The new brushless housings are taking the share of the R&D so the strength and blade design are on a whole nother level.
One of Spals first brushless fans was based off of a brushed housing and blade design that had a brushless motor droped in. The setup as good as it was was not optimized and ranged between 24-33 % efficiency. When the same 300W brushless motor is dropped into an optimized blade and housing the efficiency raises to 32-40%. The performance under higher pressures also jumped. At 180Pa the old fan put out 1000CFM while the optimized blade put out 1357CFM.

Temp Sensor Location:
My understanding from talking with Spal is to put the sensor on the hot side loop which includes the driver front of head or passenger rear of head or water pump outlet or on the radiator before it does any cooling so you have a faster reacting system and so the reading temps are in a closer range. The factory ECM triggers the fans based off of what the heads read. I have the factory ECM sensor in the front driver head, Autometer sensor in the passenger rear head, and thinking of putting the Spal sensor in the hot 5/8 outlet heater port that is currently blocked. FYI, the 3/4" heater port is the low pressure side return which is connected to the surge tank.

[Bitsyncmaster]

This all may be good for a race car but with AC the fans need to be moving as much air as possible. I do like the idea of ramped up start current but that is only nice if your fans are switching on and off a lot.

An OEM fan blade is 10.7935" in diameter.

[steve]

This all may be good for a race car but with AC the fans need to be moving as much air as possible. I do like the idea of ramped up start current but that is only nice if your fans are switching on and off a lot.

Absolute Radiator Store may have what you want.

[David T]

All Deloreans came with plastic tanks, no exceptions unless you are talking about prototypes. Nothing wrong with the plastic tanks except they got old. If you already have a tank with metal tanks, the radiator was replaced at some point in the past. That said, you might want to replace the fans. Depending on where you get the fans, you might have to remove or modify the shroud. The other common failure point is the header tank. The OE plastic one bursts. Replace with a metal tank unless it has also already been replaced. Next is the hoses. If they are old or hard they should ALL be replaced. That includes the ones under the intake manifold.

[Ron]

An OEM fan blade is 10.7935" in diameter.

[Helirich]

This all may be good for a race car but with AC the fans need to be moving as much air as possible. I do like the idea of ramped up start current but that is only nice if your fans are switching on and off a lot.

An OEM fan blade is 10.7935" in diameter.

I guess I'll be making my own shroud.

On the brushless motors, why the reference to a race car? These are on stock cars. (Will be on all cars eventually) The brushless move more air than the older fans for the same or less power. What is it that you don't like?

[Bitsyncmaster]

I guess I'll be making my own shroud.

On the brushless motors, why the reference to a race car? These are on stock cars. (Will be on all cars eventually) The brushless move more air than the older fans for the same or less power. What is it that you don't like?

I like the idea of less power but have not seen any data to prove that. Race cars don't use AC, or do they?

[Helirich]

I like the idea of less power but have not seen any data to prove that. Race cars don't use AC, or do they?

I would suppose that depends on the kind of racing and seriousness of the driver. Lol. But a race car would definitely want the most proformance for the weight and amp draw.

So I just goggled it and I could only find references to cordless drills. They claim 25% increase in power and the life is only limited to bearing life. They also claim no sparks to ignite anything. This site was not selling anything.

[Bitsyncmaster]

I would suppose that depends on the kind of racing and seriousness of the driver. Lol. But a race car would definitely want the most proformance for the weight and amp draw.

So I just goggled it and I could only find references to cordless drills. They claim 25% increase in power and the life is only limited to bearing life. They also claim no sparks to ignite anything. This site was not selling anything.

Find a spec sheet showing less power for equal air flow and I will order one just to test it. You know I love to reduce current consumption and I have a hot wire anemometer.
.