A well working rad system usually gets the water about 3C above the air temp going through it (under load). Since the bong air is only 2C cooler than normal, thats all you would gain. Submerging the rad should get the rad water about 1C (2C max) warmer than the bong water because water removes heat better than air. This brings the rad water to -2C (-1C max) as opposed to +1C (with rad on top of bong)
Personally, I would just design a bong using a large air filter (car air filter) to lessen dirt buildup, then run it to the block.
|