[Diy_efi] Propane FI

[Chris McKinnon]

>Looking to convert a 77 Olds 403 to propane for a motorhome application.
Could be either dual (gasoline or propane) or propane only.  Have both carb
and FI gasoline manifolds. Would liquid propane FI would be more efficient ?
Anyone have any advice, info or references on system and parts needed?
>
>Steve

Liquid LPG is indeed more efficient, but as far as I can tell it's
impossible for you or I to get our hands on the correct injectors for love
or money. The only time I've ever been able to get a quote on some it was in
the neighbourhood of $100 per injector, and even then they place I contacted
wasn't sure they could actually get them.

I suppose looking at some of the GDI injectors might be an idea, but I have
on idea if they will live long with propane, or even if they can take a 250
PSI rail pressure.

And indeed the vapour pressure is a problem. At 110?F it's 205 PSI. With
properly designed rails you can keep the temperature down, but 100?F isn't
uncommon in the shade on hot day, let alone in a tank under the bottom of a
vehicle.

Propane has a RON of about 110 and can run in a motor with alot higher
compression (or more boost) but on a dual fuel motor that isn't an advantage.

Chris