With an external oil cooler the risk is higher not to realize an overheated cyinder head. The oil cooler is able to keep the hoter oil in correct temparature – but the head is overheated. The external oil cooler keeps the oil on correct temperature – but do not increase the higher oil flow which is needed. (Details)
The old system with ring sensor under the plug was bad from the handling. Ofter the sensor was crashed by changing the plug. Also the correct cover of the hole was bad. So cooling air went lost
(Detail). The systme is availible for motors typ 1 and Typ 4 – 12V + 6V
ZKT 1.0
ZKT 1.1