That head was DGs early attempt at water cooling. It didn't have an official radiator, but it had water in it and a small reservoir of water as well. As the head heated up, the water "rose" or flowed through the head with the natural circulation of the water heating up and that water would cool off somewhat after leaving the head and the process would repeat itself with the natural flow of circulation- Cold to Hot to Cooler to Hot etc..
Nicholson 500x (Project)
Nicholson 185s
Nicholson 110 (That takes an atc70 tank)
Ascott 500 head/350x (Project)
Homebuilt Racer Chromoly Suspension 110 (Ragin Runt)
PK Racing Suspension 70
A+ Inc Suspension 70
AWS Aluminum 90 frame
Hi Performance ATC Suspension frame rd350
Hi Performance ATC Suspension frame 90