New Fans for Mrs Jones

[escondidoron]

I did a little home project on the Seven's cooling system this weekend.

As purchased it had a replacement fan and motor that was pretty much a joke.

It's doubtful that this rig did anything to move air through the radiator even when doubled up with the engine mounted fan.

Last weekend I scored a pair of low profile Spal fans with their writing harness off of bay. Each of them can push about 400 cfm of cooling air through the radiator. While they are rated at about 550 cfm free air, the resistance of the radiator reduces their throughput down to about 400 - 450 cfm. Even though they're low profile, they still won't fit between the anti-roll bar and the radiator. So in order to install them and be effective I needed to fab an air box so as not to repeat the previous owner's mistake. Yet the new airbox couldn't block off the radiator so that natural forced airflow would still be effective allowing the fans to shut off under normal driving conditions.

So Saturday morning I made a tool (mould) from MDF and lined it with flash breaker tape so that the finished part would come out of the tool:


This is what the raw part looked like after removal from the tool and trimming this morning:


After trimming I painted the airbox matte black, attached the fans and installed them on the car:


I tried them out this afternoon and they have made a huge difference. You can now feel the air moving through the radiator when you put your hand behind the radiator. Hopefully this will make the cooling system functional in the heat of the coming summer.

[slomove]

Nice piece of work with the bracket and the old fan really looked pitiful.

I guess the new fans will be more than up to the job. I have only a single fan in front of the radiator but when it goes off you can feel the hot air streaming from the bonnet louvers and over the wind screen. It is set to kick in at 97C and it cools the system back down to 85C within 15-20 seconds in idle. I don't think it ever goes off when driving, even in August.

[escondidoron]

Your fan is one serious piece. And so is the aluminum radiator. Very cool (pun intended).

I wanted to use a similar set up but didn't want to move the OEM radiator forward of the chassis tubes. Maybe sometime down the line if I go to an aluminum radiator.

[slomove]

Yes, it does the job. But that is stock setup and I don't know where the parts come from. I believe the radiator is a custom built piece for Birkin.

Actually the newer models have a much slimmer fan behind the radiator. Admittedly this looks cleaner and apparently works as well but without a complete shroud I suspect blowing is more effective than sucking :rolleyes: