Originally Posted by waldig
This low flow is due to the fact that the pipes are not hollow and in fact have "turbulators" or twisted copper fins that break up the flow internally to avoid any laminar flow characteristics. These cause too much flow restriction and Ill drain the coolant probably the 50th time and re-pipe the cores.
Uh this is incorrect, the twisted fins are not turbulators, that reduce laminar flow. yet they do reduce the flow rate.
What they do is, create more surface area so that the heat from the fluid can be dispersed to the main fins more efficiently. infact low flow rate is desired because you want the fluid to be in contact with the cooling fins for as long as possible to remove the heat.