It's encouraging to see you are gleaning information from credible sources!Someone on the internet said:
"It must be said that many experimental aircraft have had relatively inefficient radiator setups and consequent cooling problems"
"Most power losses are attributed to problems with the supporting systems, not the core engine. This is where careful design decisions pay benefits and poor practices often cause engine shutdowns."
"Shared information on various forums and learning from both good and bad experiences will result in better designs which should improve overall reliability."
I've done nothing but echo those exact some concerns.It's encouraging to see you are gleaning information from credible sources!
I posted an article from Contact! magazine that used the same airframe I have (BD-4B) and a Ford V6. He used a belly mount radiator and noted cooling problems on taxi.Hi, as has been mentioned, ground cooling problems are typically caused by low airflow through the heat exchanger not low coolant flow. My suggestion of an electric pump in series with an underdriven belt drive pump is for redundancy. An additional heat exchanger with an electrically driven fan can provide additional ground engine cooling and double as a cabin heater. The early Ford V-6 conversions had cooling (and other) problems. Fred Geshwender, an auto engine conversion pioneer, discovered that the stock water pump was crap at moving water and replaced it with a SVO racing water pump. No more cooling problems. That is the only coolant side problem that I have heard of. I had a cooling fan thermal switch fail while I was stuck in stop and go at LAX and the needle was headed to HOT. I opened the windows ahd set the heater on max and max fan and the needle stabilized while I got out of the airport and got some ram air flow through the radiator.