Propane Motor Fuel Injection

[Matthew Beaubien]

On Fri, 1 Dec 1995, Johnny wrote:

> I think if you build a high compression engine designed exclusively for
> propane use, it could be a real killer. Just think about how much bang you
> can get out of 12:1 compared to the 9:1 we are forced to use for running
> that swamp water they dish out as gasoline.

This is a little off topic, but I have a question as to how much power 
would be increased by increasing the cr from 9:1 to 12:1.

I have a formula which states that the percentage increase would be:

(1-new_cr^-.4     )
(------------ - 1 ) * 100
(1-old_cr^-.4     )

Pluggin the numbers in shows a gain of 7.7%. This doesn't really seem like a
whole bunch. Why do people run 12:1 compression ratios, having to use avgas
and/or octane booster, when they can run ~10:1 on pump gas and lose only a
few hp. 


Matt.
2 '71 510's (street cars)
1 '77 Civic 1200 (1.3L racecar)