I finished the new double pass radiator setup with a D&G electric water pump directly fitted to the outlet.



All done in Aluminium.

The overall size is 26" x 16" including tanks with 10" Pancake fans.

That looks stunning

Agreed!

Have you done any testing on it? It looks like you'd struggle with air through flow with the fan mounting plate.

Fan mounting plate is on the back so should be ok no? Also it will stop/reduce head from the engine getting to the rad?

Thanks for the comments, this setup with the electric water pump and the pull fans will give excellent cooling and the back plate improves air flow at speed.

With the fans off that will definitely restrict your airflow through the rad - manufacturers don't do this for a reason! Great bit of fabrication but the thermal efficiency of that rad is massively restricted I'd say!

OK, if you say so...

Were you able to test that? It would appear that the air would have no where to go with the fans off so you couldn't create the relative low pressure needed to achieve airflow over the fins.

Really intrigued as it looks like a well made piece of kit.

I guess what I'm asking is, how've you done it?

I was under the impression hot air at the rear of a radiator/intercooler expands by 3 times the area of the cool air at the front of the radiator so you will need 3 times the airflow at the rear to shift the air.
I hope those are efficient fans

Please, don't take offence - educate us! It's a discussion forum after all!

I just would have thought that you'd want to remove restrictions behind the rad to reduce pressure and promote air flow, much in the same way you usually find vents in undertrays to help draw air out from behind the rad/in front of the engine - but like I say, if I'm wrong here I'd prefer to be educated than ignored!

Fast Air flow through the rad is not always a good thing and it's the same with inter coolers aswell what you do need is to slow it down a little to allow for heat soak otherwise the what transfer won't happen and the rad won't do its job enough.

The backing plate seems good because the air can get out around the sides but on a down side the fans arnt flush to the rad so when there running they will pull more air from the gap than through the fins

As we're subsonic I don't think speed of the air is relevant. Even if one molecule doesn't 'take' its full capacity of heat energy there's plenty more. The OE intercooler duct is a venturi.

I think you might be misappropriating turbulance/laminar flow with speed

This was covered a lot on the gtr website many years ago where they where buying cheap alloy rads and the fins between the bars where to wide etc which caused over heating issue on hard boost but if they went back to standard then heat wasn't an issue. On top of that there's many a thread about cheap inter coolers with the same issue

This is a common view on forums but it is infact incorrect. Time is not a factor in any heat exchanger
.

The reasons for this have been misunderstood. Decreasing the area of fins per row (which is what *has* to happen when you increase the space between them) causes the radiator to be less efficient. I'd also hazard that the alloy used in the radiator's construction was less thermally efficient than standard. Perhaps less copper in it?

If we wanted to add airflow into the equation, then the wider spacing of fins would actually provide a relative slowing of the airflow.

Sorry to tell you this, but regarding fluid mechanics this solution is not good at all, let's say you make it worse.
Please remove the fan mounting plate.
Allmost complete cooling efficiency comes from the air stream through complete cooler if driving the car.
Both radiators have just enough power to cool your car at idle or low power, for example in traffic. Now you force almost complete air to pass these small vents.
Go another way - cut additional holes into front bumper like me or buy a front bumper with better airflow like this (ok it is not my style, but it would be definitely better than original)
http://www.fiatcoupeclub.org/forum/ubbthreads.php?ubb=showflat&Number=1404776&page=1
I even additionally cut holes into traverse beyond cooler to improve air flow.
Juergen

Hi there,

Thanks for all the feedback, I am going to add extra slots or flaps to the fan mounting plate once I have test driven the car and I am fitting a Carbonara front bumper.

There is no space between the mounting plate edges and the radiator itself. All the air entering the radiator is forced to exit via the holes where the two fans are mounted. It creates an air box of approx. 12mm deep over the area of the radiator.

The reason for mounting the shroud was to improve low speed cooling, for example in traffic, but I agree the shroud is more restrictive at higher speeds and I will look at a couple of options to address that.

Thanks again.

Matt

Double pass is good however, those fans look like ebay specials, I would be concerned that they won't have enough grunt be able to provide sufficient air flow at idle especially if an intercooler/oil cooler is in front.

Not eBay, but better than the Fiat units and there is no FMIC to worry about. Laminova charge cooler will take care of air charge cooling.

I guess anything that does not come out of Milton Keynes is not good enough.

There are plenty of cost effective non Milton Keynes alternatives like Kenlowe or Spal.

I have seen a few instances of ebay fans that look exactly like the ones you have; the problems encountered were:

Does not flow enough air to cool the engine at idle despite big CFM claims.
Moulded from cheap plastic which warped under heat and blades broke off.
Wires became stiff and discoloured due to constant current draw.
Claims of being reversible (suction/blower) but blade design does not allow it.
Not water sealed to at least IP67 which allowed water ingress into motor.
No data sheet provided and manufacture is unknown.

I hope your ones are not these but it's worth a mention.

I've tried multiple fan setups and despite there claims for airflow the data doesn't lie.

Its ok fitting things and reporting based on seat of the pants experience but always nice to compare based on live data before and after to confirm spending time and money is effective.

I've spent more money on failed attempts than successful however conquering issues is very rewarding for all involved.
Unfortunately I don't spend as much time these days fabricating as I would like but always take interest in others that push the norm.

The stock fans are far superior for cooling than any other I've used.
Even the Kenlowe fans simply don't cool as efficient on this platform.

Kenlowe were good enough to supply me with multiple setups to try any unfortunately lack of space always played a part despite increasing the swept area.

The only thing that made a noticable difference to mine was waterless coolant approx 4 degrees +-2.
And a variable controlled electric water pump which will allow the system to run as low as 70degrees constant even in traffic.
This can be used in conjunction with the stock pump or remove the stock pump completely.

I've spent thousands on different fans and radiators to no avail.


I now run a stock rad and fans and increased circulation was the answer.

Regardless of the bullshit on forums,I preffer to test things literally than in theory.


I suffered a 10 degree increase using the 2.5 platform over the 2.0 hence the need to address the cooling before pushing the car further.

An added bonus was a 4-5 degree reduction in intake temperatures due to cooler underbonnet temps and the oil temp is a good 10 degrees cooler on track.

As for the opening poster,a nice piece of engineering and I hope you notice a difference.
Don't know until you try.

Word.

I have a spal fan set as a push not a pull and I can sit in London traffic all day long because and that's with a standard rad aswell just a nice clean new one.
I've even unplugged the fan after a long hard drive (heat the oil right up) and then left it running until just below red to check oil pressure at extreme temps then plugged the fans back in to cool off and I must say the temp shot down.

I'd go for uprated fan and new standard rad or alloy one because unless your doing long track (which most of us I'm sure arnt) I wouldn't see the need.

I agree that the proof of how well this radiator will work is testing it in real life.

The mechanical water pump has been removed and I have to take a final decision on the removal of the thermostat. In my experience the electrical water pump makes a big difference in terms of cooling performance. The water pump will also be thermostatically controlled.

Locally we rarely see any temperatures below freezing and the car would always be parked inside.

I wouldn't remove the thermostat - it will run too cool at speed, as the fans won't be controlling the temps, the airflow will easily pull the temps down to 50-70 degrees - enough to start affecting the fuelling

Between 80-86 degrees constant seems to be the sweet spot.
Stat must be removed for the electric pumps to function properly.
It regulates temps within a few degrees either way regardless of in traffic or flat out.