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On 17 May 2001, at 17:35, Simon Glen wrote: > From the beginning of last month leaded petrol (gasolene) is no > longer available in Australia. I do not trust the so-called "lead > replacement" petrol which is now sold in place of leaded petrol > here. My concern is mainly with valve seats. It is my understanding that all VW engines made since about 66 are fine with unleaded gas. Here's what's important: 1) Hardened valve seats: all the VW cylinder heads have them. 2) Chrome plated exhaust valve stems: all engines came with these since ~"66, but the old ones are still available. This is one of those "gotcha's" to watch out for. Do not let someone put these in your rebuild, even though they are cheaper. 3) Bronze valve guides: all VW cylinder heads came with these, but some shops like to install replacement cast iron guides. Stick with the bronze. If these things are in good order you will have no problems. While there certainly was concern about this at one time, we have a few decades of experience with this here now, and it has turned out NOT to be a problem. There IS some concern about the octane reduction that usually comes with the omission of lead. Running gas which has too low an octane rating for your engine's compression ratio can lead to detonation and internal engine damage to things like pistons, rods, and bearings. If your CR is high, you may want to study up on ways to reduce it. Berg has a good white paper on what can be done to do this without sacrificing performance. - Jim Adney jadney@vwtype3.org Madison, WI 53711-3054 USA ------------------------------------------------------------------- Too much? Digest! mailto:type3-d-request@vwtype3.org Subj=subscribe