"Hahn, most of those fins are COLD ROLLED and bonded and the heatsink is NOT EXTRUDED... Once again you are still trying to convince us you are correct but just have the facts wrong."
-BeanAnimal
I didnt say that... if you look at what I said, it was that the end result was in effect the same. Copper is an oddball metal... it doesnt harden from cold working or have interstitial boundaries that effect the transfer of heat like steel or aluminum. So unlike extruded aluminum vs. rolled (as if), if copper is extruded or rolled, the end product is the same thing because there is no grain with copper like other metals...its like putty compared to other metals. The only way to change copper's structure is by heating it up again or making it into an alloy. It doesnt behave like steel or aluminum. Since copper is usually extruded at lower temps, the effect of extruding it and rolling it is almost the same compared to other metals.
But I really gotta call you out on this one, because in this case I think you took the science too far and applied it in the wrong way. No matter the heat transfer abilities of extruded/rolled or cast copper within the material, the rolled/extruded products are better simply because you can get thinner fins, and more of them in a smaller area. And, I must point out.. neither one is cast which is the whole point. Its worthless to argue rolled/extruded...they are in effect the same thing at this point and the point is that they are not cast.
FWIW, I really mentioned copper way back when and lumped it in with aluminum which is my mistake because technically I shouldnt have. I really was just trying to state that an extruded or sheet product might be better than trying to get a cast done. Im not 100% certain, but I know that one company I worked for that was big into heat transfer tech (modine.com, they are leaders in heatpipe technology right now), and the idea of cast copper/composite sinks was a costly one. Almost everything was done with extruded aluminum and copper that was extruded/rolled and then we stamped it unless we were looking into getting hundreds or thousands made. The key thing is that is wasnt cast.
I am sure, and so are many heatsink mfg's: more fins that are thinner are more effective than thicker fins that are fewer in number. Any method to maximize the surface area, and therefore the transfer capacity of the sinks is going to be the better performer. In areas where there is higher delta between the heat source and the surrounding air, or the heat buildup isnt such a bad thing (once again, the delta in effect), thicker cast fins are just fine... that being said... cast is all that is needed. But when more performance is needed... like lowering that car's engine temp on a blistering hot day in a small space... thinner walls, more fins, etc are put into play. Most CPU cooler makers have gone away from cast HSF combos to purely extruded/rolled copper pieces that are stamped. And while cast might be just as good in this case, or FWIW, all we need... using some sheet copper to make fins and bonding/welding it to the pump might be easier.
That link you provided does mention a very valid point about a heat sinks mass/volume. The idea that cast sinks and thicker fins are better could be because its easier to get more volume of sink material... thinner fins means you might have to use more fins or longer fins to make up for it. Its a balance of mass and surface area. The mass allows for absorbtion from the source, the surface area allows for dissipation. Sometimes with thinner finned sinks, you will see a larger base block that the thinner fins come off of to get the mass. Or, these days, heatpipes... but those need to be customized to the application.
Hey, maybe were getting back on track here after all...
Another option that has been overlooked, but might be a great option for those with extra pumps laying around... liquid cooling. A simple loop with a small powerhead and radiator might be a good idea... just have to find a radiator... but thats easy.. you can get one from a car at a junk yard or parts supplier for cheap.
BTW, what was the initial cause/concern again about the pumps getting hot anyways? Just wondering if its even an problem that has to be dealt with... we never determined that a heat sink was even needed... maybe just an idea, and an invalid one at that. I know that there are a bunch of people trying to do something like this in that 'swirler stein' thread... adding heat sinks to the timing motor shrouds... but its kinda odd because Paul from Oceansmotions even chimed in to say that thats very common and expected with timing motors that they just run hot... so why even bother?
and about 15 pounds of extruded almumin heatsinks purchased from a guy on ebay)
