FUEL OCTANE?

[Jorge022770]

Guys, quick question.......I can't find where I read once about the proper octane gas for the 1600.......87? 89? 92? Thanks in advance for your input.

Jorge

[toolsnob]

I think that using 92 makes them run the best.

[Cochecita]

I hear you can get the really good gas (107 octane) if you take some gas cans down to a small airport and tell them you need gas for your "Sea Plane." I always run premium (92) in my 68, but i'm curious to see how it would like the good stuff. Not very convienent for a daily driver. You could probably get it by the barrel if you have a place to store it.

eddie

[Tycorcr1]

here in vegas you can buy 100 octane unleaded "race fuel" at the pump at some Rebel ( union 76 ) stations around town. $4.49 a gal. The car deffinately likes the higher octane and it smells really good too. I notice a slight change in idle and engine smoothness between 91 and 100. Oh and i always add a lead substitute when i fill up.

[nomadtrash]

You should use the lowest octane gas that does not cause knock. Octane is a rating given based on knock resistance. Lower octane ratings ignite easier and burn faster. Higher octane ratings are harder to ignite and burn slower. You can hurt performance and have higher emissions from too high octane. If your car runs on 87 without knocking then you don't need higher octane. The main reason that high performance motors need it is because of increased compression ratios and spark advance. I don't know if a recommendation was ever released from Datsun for the Roadster.

[Jorge022770]

Thanks for the input guys! I guess I'll have to wait until I have a muffler + all piping installed....need "silence" to determine if theres knocking or not!

Jorge

[steve68]

You should use the lowest octane gas that does not cause knock. Octane is a rating given based on knock resistance. Lower octane ratings ignite easier and burn faster. Higher octane ratings are harder to ignite and burn slower. You can hurt performance and have higher emissions from too high octane. If your car runs on 87 without knocking then you don't need higher octane. The main reason that high performance motors need it is because of increased compression ratios and spark advance. I don't know if a recommendation was ever released from Datsun for the Roadster.

finally someone else that knows this.

Well i have to run a mix of 92 and 110 leaded fuel for mine, about 2ga. of 110 just to make sure it doesn't knock and also no vaccum advance. as the head has been shaved twice so im running close to 11:1 if not more.

static compression is better to tell you what gas to run (psi from cyl.) mine is around 225 and i think stock is 180 anyone?

thanks
steve