Sign in to follow this  
Followers 0
AUSmoker

What fuel to stop detonation with high compression help please

5 posts in this topic

I am putting together a wr400, 444cc big bore with 13.5:1 hc piston.

I was hoping to run 98RON fuel.

How do i find out what fuel to run. I know if it pings to run higher octane, but how do i determine the correct fuel.

I can get higher octane but its expensive and not available at the pump.

Can i run 50/50 pump and race fuel? Can i use an octane booster? Is there any fuel i cannot run Eg. Methanol, ethanol etc.

There is a 10% ethanol mix available at some pumps thats called 100 octane.

I live in Australia so im talking RON ratings.

I want to know how to test my new engine safely to find the right fuel, and know what additives work.

Hopefully 98ron will be ok but if its not i can get up to 106ron for $$$.

Does any changes require jetting/fuel system changes.

Thanks for the help and only answer if you have credible knowledge.

Share this post


Link to post
Share on other sites

Race fuel mix is the most common solution

You mix to the minimum amount of race fuel to eliminate detonation

13:5 is a substantial increase, so 50/50 should be expected

Ocatne boosters are typically just Toluene: not a very good fuel source on it's own.

For more detailed info, you should contact the Piston company

Share this post


Link to post
Share on other sites

and I woundnt experiment with fuel/ combustion ratio's etc..

98 should/ could work fine,

but if not, use a booster, make sure "other" fuels dont "eat" rubber/ plastics...

Share this post


Link to post
Share on other sites

98 RON should be more than enough.  In fact, the originally required 95 RON should be adequate.  Here in the states, gas pumps are all labeled with "AKI" ( anti-knock index), which is an average of RON and MON, and most pump premium is labeled 91-92.  This is roughly equivalent to 95-96 RON, and generally works out as being enough for most people running 13.5:1 with no other additives.  I wouldn't worry about it too much.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0