Oil recommedation for a rebuilt Vanagon 1.9 watercooled engine

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Jul 23, 2003
Nova Scotia
I have a 1984 Volkswagen Westfalia Camper with a 1.9 watercooled flat four that is in the process of being rebuilt. I was using synthetic before the engine rebuild and the engine did not leak more than a few drops here and there. It ended up with severe blow-by due to rings/cylinder wear. I have only had the van for a couple of years, so the internal engine condition was an unknown. Some of the Volkswagen group that I have talked to say that synthetic oil should not be used with an older engine design as it will leak and have blow-by. They recommend Castrol 20-50. Most are air-cooled VW owners and my guess is that their recommendation is based on the fact that the air cooled engines may be set-up with looser piston to cylinder tolerances to allow for higher operating temperatures. I have used synthetic in all my other vehicles and don't want to go back to the dino oils. I reason that 15-50 Mobil 1 is going to be a superior to a 20-50 dino oil. I understand that I should use a dino oil for the first 2,000 km or so to allow for proper break-in. Do you think the 20-50 is too heavy for break-in? The weather is between 20-30C and the little 1.9 works pretty hard in a 5200lb GVW vehicle.
You might want to look at breaking it in on a good 15W40. Then if synthetic is what you want, the Mobil 1 15W50 would be a good choice. [ July 24, 2003, 10:07 PM: Message edited by: Johnny ]
You don't need such a thick oil (15w-50, 20w-50) in a VW water-boxer. Especially if your summers are only 30C (86F). I'd use a 15w-40, or 10w-40. Maybe a 10w-30 or 5w-30 at the thinnest.
a wasserboxer is basically a type 1 and type 4 hybrid with waterjackets. given that info, id look at that the type 1 and 4 big name guys are running (the ones who build engines to last 100,000 miles and such) i dont know man. i do know that almost everyone runs 20w50 in their type 1 and 4's unless its real cold out. all the big name guys use 20w50 in their engines for street. id probably agree with texastdi's recomendation. your engine most likely runs cooler than the aircooled versions, so a 10w40 or 15w40 would probably be good. also, according to the big shots of the flat 4 world, synthetic is a-ok.
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