Ancient History

[tom cloud]

>At 02:44 PM 9/3/96 -0500, you wrote:
>>I think 12 mpg from a 455 is fantastic.  Can't see how you get this
>>good -- FI or carbed.  What's your rear end ratio?
>>
>>tom
>
>OK, I new I'd get some mail when I said that, so for the curious, my car is a:
>
>'78 Trans Am
>1970 455 2bolt main from a Bonneville
>stored heads from that motor (10.25:1 cr too high)
>
        [ snip ]

I haven't dug up my stuff about VE and CFM and displacement, but seems to
me that an xxx CID engine is a pump that always pumps xxx CI of air every
two revolutions (assuming a 4-stroke).  All that changes is the density
(i.e. throttle closed = lower density A/F charge).  And I thought that
running R-E-A-L lean meant burning things up (I KNOW it does!).  So, it
takes a certain amount of fuel to just coast, much less make any power.

Like I said, I haven't dug up the stuff, but I remember trying to mathematically
anticipate 'good' mileage for my 351-W with a 3.50:1 ratio diff and was able
to think 14 to 16 would be a reasonable goal with higher values theoretically
feasible.

So, how does one take a 400+ CID engine and get that kind of mileage
unless he's running a 1.7:1 rear end (i.e. L-O-W r's) -- even if he had
100% VE ?

Tom