Head upgrade and now running hotter

[mk1rally]

Hello, just want to gauge what people are running on the higher power engine's to keep cool. Side mounted Rad, Mk1 mini housing.

Recently changed to a 7 port and it goes very well, however I am starting to get overheating issue after prolonged high power use. If I cruise around or on easy laps at track day's the temp stay fine and around 80 (Blanking sleeve fitted). I'm already runnnig a electric fan and a minispare's 2 core. It's the MED 7 port head, that is dry decked (there is no waterway's through the block to thehead, it routes via the core plug next to the standard stabilizer and u bends back into the head). In theory, it should run coolerbecause of this and the fact it's alloy.

Wind it up for a few miles and it starts to creap toward and into the 90's too easy. It seems to be holding the water fine. The head gasket is fine and the rad cap is not blowing off (14lb). The engine is just under 130 hp now and obviously that means extra heat. This would add up as when I 'm not asking the engine to create that power, the cooling is fine.

I was wondering, are the alloy rads that better at cooling than the copper 2 cores?

Should I also run a mechanical fan due to the possible restrictive early surround?

Or should I look at a bigger rad or a additional heater matrix?

The cooling was fine on the previous head set up (around 95hp) but I removed the mechanical fan as I always worked that after 30 mph, they just ate energy.

[wil_h]

If using a sidemount rad you really need to run the fan. I tried without a fan just on hillclimbes and found it just got hot.

Although you would think the fan does nothing above 30mph, there is no natural airflow through the rad without the fan. I now use a metal 4-blade type which is more efficient at higher speeds.

[Smiffy]

Had similar problems, a 4 core rad fixed it.

[greyghost]

mechanical fan and "Water Wetter", i've used this in mine for a while now with no issues. that includes driving rapidly up a steep hill in 48ºC day. temp stayed as normal

[mk1]

I too would suggest that a mechanical fan was an excellent place to start & then take it from there.