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Proj. Cosmo

Nate Bowen

Arturo Chia

Old Updates

This is regarding Pre-mix concerns with diluting gas.  It includes posts from Brian D. Cain and Ted Koseki from K2RD.

--- "Brian D. Cain" <brian.cain@flukenetworks.com> wrote:

> Quick reminder again -> Unrelated, but who cares.  :-p

Yep, off-topic alert.  :P

> I don't believe so, Eric.  One, it's such a small ratio and it burns easily
> in the combustion chamber.  Secondly,
> in reference to the Mazda Rx7's oil metering setup, you're shooting a ~220:1
> ratio of 4-stroke motor oil into the chambers.  I ask you rhetorically ->
> which one lowers octane rating more?  Somebody like Ted would know more about
> this in specific than I would.

Adding ANYTHING other than the cyclohexane family of aromatics or some of the
more exotic fuels (i.e. nitromethane) will lower octane.  Remember, octane is a
fuel's ability to supress pre-ignition - it really has nothing to do with power

With that said and done, adding motor oil or pre-mix will lower octane, period.
Pre-mix is designed to burn cleanly, so it won't affect octane as much as
motor oil does.

We usually recommend to run about 150:1 ratio for street, minimum.  Race ratios
are 100:1 - 75:1 ratios, minimum.


Ted Koseki                          K2RD Racing Development
f8ldzz@yahoo.com                         Founded since 1999
<http://rx7.foci.com/tkoseki>                "No excuses..."