hotdat

Thanks, that has saved me a lot of trouble. Another thing is, there are 3 main types of unleaded fuel in Australia, we have our plain old unleaded (91ron), premium unleaded (95ron) and most of the big company's have there own name for there high end fuels,, like Shell have one called V-power and B.P has one called Ultimate, these are (98ron) and from what I know Shell has a fuel that has only been available for about 6 months and only in major city's called Optimax Extreme and it has 5% ethanol and an octane rating of (100ron). It's not available anywhere near where I live and I have heard its not good anyway so I will be running it on (98ron). Is the 98 higher than your premium seeing? As we have premium rated at (95ron).

I have done a bit of a search but still need a bit of help. I am purchasing a noss head, i live in Australia and our pump fuel highest octaine rating is 98, I live 96 meters above sea level.I am fitting a 64.5 piston and the engine is a stock port. I wish to advance the timing as well. What size domes can I use? And how much timing can I run while running on the 98? Assuming that the American and Australian fuel ratings are the same. Please correct me if I am wrong.