DIY WB update

[Greg Hermann]

The extra load on the
>engine
>> from the taller gear allows the wider throttle opening and consequent
>> reduction in pumping losses.
>
>Also, that assumes that the engine is still operating in an efficent rpm
>range.   It's easy to lug and engine with too much gearing and then have
>even worse economy.

Yep. Another way of saying that cam is a _very_ important part of tuning! :-)
>
>> Part of the reason for higher power on the rich side of stoich is
>selective
>> burning of the hydrogen in the fuel before the carbon gets burned. The
>> hydrogen fraction has a higher heat of combustion than the carbon does,
>> hence more heat and power for a given amount of air with a somewhat rich
>af
>> ratio, but less mileage because not all of the fuel (some of the carbon
>> part) is being burned.
>
>Isn't that the reason for having to add timing, when going, leaner?.

Well--mixture lean of stoich tends to burn slower than at stoich, so yeah,
more timing needed if going lean.

Absolutely, it all has to be right to get the mileage benefit.

Greg

>Bruce


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