The Stovebolt Site Forums The Shop Area Engine Shop engine temp

now back to the matter at hand, 20-50 would be most likely to heavy. There are at least 2 very good articles on oils, with emphasis on zddp levels. One is by Bob Olree, a GM, or at least retired GM engineer, who by several accounts is virtually without peer in this field, and one I just found the other day on VCCA a fella named Vidman. Who is, or was an engineer in this sort of stuff for several of the major oil comapanies. They both say pretty much the same thing, but given the probable oil temp achieved in these engines 20-50 would be way out of its acceptable range. (this is one of the reasons I want to get one of those little laser gun thermometers.) I won't try to summarize their articles, because, well, they already did it. The one interesting thing I found out is, the zinc (the "Z" in zddp is there for anti-corrosion) While it is actually the phosphate, (maybe phosphorus, thats why I let them tell the story) the "P" in zddp is the actual anti scuffing ingredient we are looking for. The article by vidman is very recent and includes the little code numbers and what not to look for on the side of oil containers, mostly it seems the diesel oils are the ones with the appropriate amount of zddp, but here again, you read the stories and make your own decision. As far as your overheating, technically if it is below boiling and it stops rising, it isn't overheated. Did you use a new/different thermostat upon reassembly? As I said I ran my truck at 195 (why is there no symbol for degrees on these computters?) for 28 years, as well as every car I owned up until recently when I started buying new cars, and I have a feeling the new cars run even hotter, but I don't know that for sure. I have never had a fresh engine get hot, I have only built 2 auto engines, as I have never really had one fail. But diesels we would rebuild at least one a year for the about 20 years I spent up in alaska and in the merchant marines. So as long as it stops by 200 degrees, you are fine. Nonetheless, you should double check the accuracy of your gauge, which since you never mentioned water blowing out the top of the radiator like a geyser, seems to be accurate enough. The most important part being is the water stays in the engine, once it starts blowing then you are screwed.