It's almost done. All i need now is to put everything under the hood. For now total cost is ~80 PLN and I doubt that it will be increased further. I used salvage parts mostly that I had in my junk.
It'll be 750W 230V heater with electric pump for circulating the coolant. Build from a heat exchanger coolant-engine oil from BMW (old Berta's engine), old electric heater and electric (12V) coolant pump from Mercedes. Pump will be used to run coolant during hot weather and EOCing.
So parts that I've used so far are:
1. Oil cooler from BMW
2. Electric heater 750W 230V
3. Electric pump 12V from MB
Pictures aren't mine - sorry.
I needed to cut out the oil cooler core and close with epoxy the oil-in and oil-out ports. Then I cut all the plastic from the electric heater, so it could fit the biggest coolant port of the coolant-oil heat exchanger. I used epoxy to glue it in again. Now i need to put it under the hood and connect electric cables and it should work. Hopefully
I'll do my best to take some pics during the installation process.