[Diy_efi] Re: LPG vapor injection with gasoline injectors: calculating fuel req.

[John Smith1882]

Expected fuel(vapor)) pressure will be ~40psi.

LPG comes out of portable cyclinder as vapor already unless you turn it 
upside down. No convertor necessary.

I expect the gas will get cold from the expansion, so I guess roughly 
30-40*F/0-10*C. Hopefully it won't go any lower than that.

I have no idea what the propane/butane percentages are for the average LPG 
here in the U.S. It's not critical anyway; I just need to figure out the 
numbers to "fool" the MegaSquirt into making a working basemap. For example, 
if I need 50% more propane than gasoline, I can tell the MS it's a gas 
engine that is 50% larger than what I have. However, before I can do that I 
have to know the reduction in mass flow from liquid gasoline to vapor 
propane through the same fuel injector....or something like that. I'm still 
learning about liquid/vapor/caloric values/etc.

In RE to the rest of your post that I excluded: I don't have a dyno and 
won't until I build one. I don't have an exhaust gas analyzer nor 
vepor-specific injectors and it is cost prohibitive for me to purchase 
either for this project.



>Date: Fri, 09 Jun 2006 20:40:14 +1000
>From: Phil Lamovie <phil at injec.com>
>Subject: Re: [Diy_efi] LPG vapor injection with gasoline injectors:
>	calculatingfuel requirements
>To: diy_efi at diy-efi.org
>Message-ID: <4489500E.7C70ED18 at injec.com>
>Content-Type: text/plain; charset=us-ascii
>
>
>Hi John,
>
>Without specifying the pressure and temperature of the activity
>it is impossible to calculate the equivalence in litres of flow per
>minute.
>
>You don't say how you intend to produce the vapour. If you are using
>a converter with an internal regulator or some other form of pressure
>control that will answer some of your question. The temperature of the
>vapour will be more difficult to determine.
>
>That said you also need to determine the propane/butane mix so that
>you can correct for energy per unit volume.