Friday Night’s Jobs

After one night, I’m still on schedule! Yeah!

First item to attack was to finish off the last bits of the cooling system.

I modified the header tank to also incorporate the overflow tank, painted it and fitted it.

Another view:

The top part of this tank will collect all of the air bubble that are produced in the coolant.  Hopefully these will be drastically reduced with the electric water pump – the normal mechanical pumps can cause cavitation the pump at high RPM, putting air bubbles into the system (bad for cooling) and also robbing horsepower.

The system catches small amounts of flow from all of the highest points in the water system and directs them towards the header tank.  At the bottom of the header tank, a pipe at the very bottom of the header tank connects to the inlet of the water pump, causing a continual flow from from these high points into the header tank.  This will drag the bubbles into the header tank, where they will stay.

These air bubbles will stay at the top of the header tank, where they will be forced down into the lower catch tank as the water expands when it heats up (there is a hose connecting these two tanks together).  As the motor cools down again, the water shrinks again and only water will be sucked back in – the hose connects to the lower catch tank at the very bottom.

I then got onto doing the fan.  I got a 16″ fan from SuperCheap during their 20% off everything sale – hopefully it’s capable of doing the job.  I welded spuds into the radiator to mount the fan.  I am not a fan of mounting them straight to the radiator fins as some people do (See what I did there….).

If this was my road car I would have made up a fan shroud for it, as it increases their efficiency when you are stationary.  When you are going at speed, the fan is not actually needed, so I want to keep the airflow at speed as good as I can make it, and hopefully just have it be enough to keep the car cool enough while stationary.

I then routed all of the coolant pipes and tied them up nicely, same with the vacuum hoses under the throttle body.  Added the MAP sensor and the boost controller, ready for the wiring tasks in a few days time.


I filled large portion of the system will coolant, then hooked up a battery to the water pump and turned it on.  It was very pleasing to see all of the flows, complete with stacks of bubbles/air, going into the header tank as the system was bleeding itself.  I kept topping up the header tank until the system was full, and the water pump was running silently.  Very pleased with how it works!

I have a wedding to go to today (Sat), so no progress will be made – see you Sunday.




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