Cooling enhancement

Driving the car in the Alps has been quite demanding on the engine and the gearbox. Better cooling was on my wish list for quite some time.

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I kind of like the look of the front mounted fans. The yellow ASTI fan is weak and cheap (was used in Renault low cost vans). So this is this the one that had to go.

A 12'' fan is the biggest we could cram in the engine bay. I did not want a SPAL fan with "modern" (curved) blades: straight blades are a bit nosier but do provide more airflow. Straight blades do look much more period correct.1850cfm.

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The gearbox radiator was replaced by a larger Hayden (plus bigger oil pan). The bypass had to go as there is a Stewart Component inline cooling pump on the bottom. More on that later.

 

Mishimoto 12'' Heavy Duty (https://www.mishimoto.eu/race-line-high-flow-fan-12.html#features).
Prop diameter : 12''
Outside diameter : 13'' , depth : 3.9''
Nominal Current : 12.8A (still acceptable for the Bosh relay that takes care of it together with the front RH fan).

The Heavy Duty does fit with a bit of persuasion: had to move the oil radiator 1cm further on the right. They have an extra-slim variant that would be an easier fit, but it is almost 50% less powerful (1150cfm). As said, I also prefer the old-school look (the slim fan does not look good to me).

 

I've already refurbished the Lucas Fans... See my old post on the subject ( https://www.ferrarichat.com/forum/threads/lucas-cooling-fan.586356/ ) : these fans are easy to source or fix or replace by more powerful units (pick whichever solution you prefer...).

If you are only relying on these two fans, I would suggest at least to put new brushes and adjust timing (slightly unscrew the motor endbell and tilt as much as you can the endbell on the opposite direction of the rotation). I would even consider a DeTomaso Pantera fan shroud (see Pantera diagram here : http://www.pim.net/11.1pim.html). These are cheap and easy upgrade on a stock setup.

On his 400GT, my brother is probably going to retrofit the yellow fan from a 400i. This upgrades cooling to three fans instead of two, based on "stock" Ferrari parts.

 

Worse... No controller at all. My pump is a Stewart Component, that's quite a different design than EWP when the pump does not operate, the coolant can freely flow around the propeller. So unlike the EWP it does not restrict the flow when switched off.

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At the end of the day whether it is ON or OFF the mechanical pump will still operate and (over)cool the engine. We will see how the engine temp rises without thermostat and if it is way out of spec I will have to find another solution. Will send an update once I've started the engine...

For now I am missing the spring and tap of the oil pressure relief valve so stuck for another 2 weeks.

 

That's quite a big pump actually. So it requires a bit of space and given the heavy weight (2kg) it has to be secured on the frame. I really like the specifications of the pump though: its is much more powerful than the DaviesCraig (220l/minute) and the inline design makes integration a bit cleaner.

We have removed the 3way pipe (ref 30, yellow highlight) and replaced it by the pump which is basically the same length. Also added a bracket which has been bolted on the frame parallel to the anti-sway bar.

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The best solution would be a 3 way hose placed between the pump and the radiator. It is not as easy as it seems since there is a slight bent, the radiator outlet is 44mm, the pump inlet is 48mm and the bypass is approx 30mm. So it will have to be custom made. The design of the hose between the pump and engine also has to be revised as there is probably not enough flex. Black hose and period correct electrical connectors would be a plus.

For now as you said it will take quite some time to warm up the engine.

 

I had a closer look at the setup on the other thread. The shroud is only on the bottom of the radiator. I presume that when his car was converted from 365 to 400, they also imported the radiator that protrude below the spoiler. On the 400 no issue as the new spoiler has a protrusion, but if he still has the stock spoiler the radiator could be exposed to road debris, so this shroud is basically protecting the radiator instead of the 400 spoiler. Got to agree though that this is restricting the airflow hence my recommendation to use flaps.

As far as consumption is concerned, the efficiency of these fans is higher than the lucas, so although instantaneous consumption is higher, in the long run they do provide the same amount of cooling while absorbing less electrons (in other words I would expect these to not operate continuously unlike the Lucas).

I would however check that the fans relays are connected on the alternator positive post (the one that is bolted on the left fender, next to the steering pump), and not directly to the battery as this would bypass the ammeter. On the contrary Choptop would not realize his fans are depleting the battery. Given the "Mercedes setup", an accurate ammeter reading is mandatory!

 

Here are the latest findings and updates to my setup:

First : we should follow the 365 owner manual coolant recommendation as despite all my modifications I could not lower the temperature below 110°C with Motul 50/50 premix (my Alpine road is extremely hard on the engine). The 365 OM does recommend 20% Glycol (3.5liters). In order to stop spreading toxic coolant everywhere, I've switched to 100% distilled water and Mocool (Motul's equivalent to Redline's water wetter). The temperature drops to 90°C! (same road, same coolant brand, just removed all the glycol).

Second : I've modified my overflow tank so as to limit spillover. The factory setup is troublesome as coolant that gets into the expansion tank is trapped and cannot get back into the system. This is extremely annoying as my road is so steep that when going down-hill in a right turn, coolant flows in the expansion tank! I consequently made a coolant pickup out of an 25cm long 8mm diameter aluminium tube. The diameter was reduced down to 7.5mm on a lathe in order to be slipped inside the expansion tank inlet and reach the bottom of the tank. This pickup allows to suck back the coolant to the radiator when the coolant is not expanding anymore (i.e cooling down).

Third : I've bought a new radiator cap. CALORSTAT/Vernet reference RC0153 is the European equivalent to the Stant product people use in the US. I've tried the version rated for 1.1bar without spring on the valve. The 1.1 bar allows to reach 110°C without spilling coolant everywhere. The free floating valve allows to suck back coolant from the expansion tank to the radiator.