What are considered high compression ratio for motorcycles?

For example, motorcycle racing engines can use compression ratios as high as 14.7∶1, and it is common to find motorcycles with compression ratios above 12.0∶1 designed for 86 or 87 octane fuel. Ethanol and methanol can take significantly higher compression ratios than gasoline.

What is the highest compression ratio for 95 octane?

95 Octane. Gasoline with this octane number is known in Indonesia under the brands Pertamax Plus (produced by Pertamina), Super Extra (produced by Shell), and Primax (produced by Petronas). This type of gasoline is advisable for car engines with compression ratios of 11:1 to 12:1.

What is the highest compression you can run on 93 octane?

If the cylinders are sealing up well, I look for 190 psi as a lower limit with preferably 200 psi as a target when using 93-octane fuel. For every octane number less than 93, the compression pressure needs to be about 5 psi less to avoid detonation under normal circumstances.

Is high octane gas better for a motorcycle?

A higher octane gas will net more horsepower, get better mileage, or offer better thrall response. High octane gas alone does not yield more power unless it’s preventing detonation, which is also known as engine pinging or knock. The higher the octane, The more resistant the fuel is to detonation.

Is a higher compression ratio better?

A higher compression ratio (CR) is beneficial for engines. That’s because the higher ratio allows for an engine to extract more energy from the combustion process due to better thermal efficiency. Higher compression ratios allow the same combustion temperatures to be achieved with less fuel.

What is a good compression ratio for 91 octane?

The generally accepted conservative estimate is 8.0 to perhaps 8.5:1 dynamic compression ratio for 91 octane pump gas. This tends to be true for older, traditional engines with less effective combustion chambers. But for later model engines with better chambers, that could be improved to 9.0:1 dynamic.