Flash/fire point and burning in the combustion chamber.

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Jul 15, 2002
Mississauga, Ontario
Are the flash/fire points directly related to how well/easy an oil will burn in the combustion chamber? This stems from the argument that rotary engines shouldn't use synthetic oil because they don't burn as well, and since rotaries actually rely on the oil in the chamber to lubricate the seals conventional oil is recommended. [I dont know]
Well Terry claimed that Mazda IMSA was running boutique oils in their three rotor engine. I had heard that they had a custom blended synthetic that they were useing on speed vision so buy all acounts at least two different sources have confirmed their use of syntrhetic. I think that if anything the choice of synthetic might be an important one. Redline has the least deposits of any commonly available synthetic oil. If you decide to add two cycle oil to your gas to enhance lube until the oil injection comes online you might consider synthetic two cyle oil.
Just to bring this up again.. The RX-8 is finally out on the streets and the inevitable 5w20 vs 10w30 along with the "no synthetic oil" arguments abound. I have my own opinion on the 5w20 idea, especially since European versions recommend 5w/10w30 of course. Regarding the synthetic issue though. I still don't know if the syntheic oil would resist burning or leave deposits that could harm the rotary engine? Many people are reporting Mazda techs/reps advising against synthetics.
I used to think that they did have a relation but I don't know anymore. Look at Mobil 1. Most of their viscosities have higher flash/fire points than conventional oil, yet you hear many people here stating that when they use Mobil 1 they have oil consumption problems but when they go back to dino oil, the problem goes away. That is why I don't understand why Mobil 1 seems to burn off, even though its on the thin side, when it has fairly high fire/flash points. Wayne Wayne
Regarding the Mobil1 vs dino consumption I think that's due to the fact that M1 has smaller and even molecules compared to dino ones, thus it's easier for them to get by the rings. The rotary engine actually uses oil on purpose..
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