yalan 0 Posted November 16, 2007 They rupture because of the plastic end cans. If VW made the matrix with aluminium end cans, the problem wouldn't occur. Don't you lot read? :roll: :lol: Its not really as simple as that. Aluminium is better than plastic? Lots of properties to balance out. Aluminium is a ductile material - to make an Al cap which will bear the crimp forces which hold it in place would take a very thick cross section. But if a thick gauge of Al is used then it'd be both expensive and tough to draw out using traditional equipment into shape without further heat treatment processes. Unless of course you're talking about using welded up box caps as per custom rad/cooler projects? very expensive and only now really becoming viable with modern manufacturing techniques. Not really something which VW would have considered 15 years ago. All aluminium exchangers are really only becoming popular now because of End of Life regulations forcing manufacturers to recycle. The manufacturers are concerned with life costs of their products & by having plastic tanks makes recycling their units more expensive to dismantle than bearing the initial extra costs of making the part all aluminium. 15 years ago no-one cared all that much about EOL. The metal end caps we used to find on radiator panels were normally copper which is nice and easy to form and deals well with heat cycling but with the rising costs of copper plastics have taken over as the norm. A well constituted plastic with reinforcement bindings should and does survive well in the harsh conditions a radiatr is subjected to. Is it really so surprising that a heat exchanger exentually fails after x million cycles? No doubt it is possible to design an exchanger which will survive into the vehicle's 200,000th mile, but who would want to bear the extra cost of producing that part? Quote Share this post Link to post Share on other sites