Originally posted by desert_450r@Jul 21 2004, 11:02 PM
Lude, He said:
QUOTE
I am thinking for the next month of running distilled/deionized water and Redline additive.
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Clutch,
Actually, there's a curve to your thinking ... Running TO MUCH octane for your compression ration can actually INCREASE combustion temps ... Higher Octane Value = Higher BTU value as a result ...
The idea is if you have for example 11:1 compression and at a certain conditon and you have pre-ignition OR worse, detonation, that can create excess heat ... Pre-ignition can not always be audibly heard BTW ... So if you are pre-ignitiong, higher octane will bring the motor back into "time" whereas the explosion happens at the right time ...
If you run too much octane with the 11:1, it can actually be too resistant to ignition and the compression needed is not there to "pre-heat" the mix ... This can cause delayed combustion which will cause excess heat generation also ... (namely on the exhaust side if the head)
One of the by-products of combustion is heat and if the heat of the power stroke happens late, it is not happening within the intended timing of the motor, and the rate of cooling within the combustion chamber is altered ...
In addition, depending on the exotic fuel's additives, more energy per stroke can be part of the fuel's characteristic and this would compound the problem ... There are many different formulations of race gas and can be very different ...
Unfortunately more is not ALWAYS better with octane ... At least not in 4 Strokes ... I would run 92 pump octane, a lead-like additive for your valves, and keep a Gallon of Zylene or Toulene with you to bump the octane if you need to ... I run 10% of either with 91 octane in the hot months ... 10% of either of those should give you about 2-2.5 true octane points (not tenths like the sham store adds give you) ... Here's a simple formula added to simple 92 octane pump gas:
Toulene
10% = 94.2
20% = 96.4
30% = 98.6
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Xylene
10% = 94.5
20% = 97.0
30% = 99.5 [/b][/quote]
dez. I think you know too much.....you are full of info....I admire that.