

| Subject: | Re: Air cooled to Water cooled |
| From: | Rico Sapolich |
| Date: | Fri, 25 Jun 1999 09:15:11 EDT |
In response to an inquiry regarding the installation of a water-cooled engine into an air-cooled van, Larry wrote: <<Next, get a couple lengths of 1.25" electrical thin-wall conduit (EMT), a tubing cutter, and a conduit bender. Use these for coolant lines from the engine compartment to the radiator. >> There are two shortcomings in using EMT for this application. Firstly, the bending radius of 1.25" EMT is quite large (about 9"). When the occasion arrived to replace these lines, I planned to use stainless and twist my own, I obviously NEVER wanted this whore's nightmare to occur again. But, none of the job shops I approached had the tooling required to replicate the tight radii of some of the factory bends. Before common sense set in, I toyed with the idea of buying tube fittings, doing the fit-up myself and then having the whole mess tigged together. Unless you have worked with this material before, do not fool yourself into thinking you will simply heave on the handle of a manual bender and this relatively soft metal will yield to your desires. Even guys who work with this stuff daily will use1/4 bends and couplings if they do not have access to a hydraulic bender. The 1.25" designation is a nominal size, the actual O.D. is about 1.5". Also, any bender made for field use will flatten the EMT thus changing its cross-sectional area. Secondly, I think there is the potential (no pun intended) for a galvanic reaction between the dissimilar metals brought into proximity with the use of EMT for this application. I know that the Zn-coated EMT will not contact the aluminum components directly; still, I think that the circulating coolant can be enough of an ion carrier to cause a corrosion problem. For example, it was my experience that when Volvo started using aluminum heads, their Cu radiators did not last as long. If you noticed, somewhere along the way VW started using aluminum radiators in the Vanagon. While this may have been mandated by some beancounter, I must not have been the only one whose Cu radiator suffered from incontinence at an early age. Anyway, the EMT will probably rust away in short order once the thin Zn coating is sandblasted by road grit. The best bet is to get the OEM parts. By the way, I have a pair of unrusted coolant lines should anybody want to make me a fair offer, FOB. They are from an '84 and I am near Pittsburgh, PA. Richard
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