Ok, here is the deal. I was doing some reading online about liquid propane conversions on pistion engines. Now my thought process is a typical rotary nut perspective, if they can do it, we can! I looked into it, a 12a would be ideal for it, due to the fact it is stock carbed, and i have a spare sitting in my garage waiting for me to play with it.

Now, the specifics:

In order to do this, i would need to modify my stock carb, or modify some aftermarket (most likely i am going to stick with the stock, simple because i have it sitting here). The modification involves drilling holes, tapping them, and putting extra jets in to handle the propane gas. Running the necessary hoses, a liquid to gas converter, and obviously put the tank in. There are also some other simple steps like putting a switch in to "prime" the carb on startup, putting a fuel bypass valve in (so i can run gasoline when i can't get a refuel or lpg) and figuing out how to mount an easy access refilling setup so i don't have to take the tank out for filling.

From the research i have done, this would actually be an inexpensive process, the parts themselves are really not all the expensive, and the install seems pretty straight forward. Since the gas is pressurized no need for a fuel pump or anything like that. And i plan on putting a fuel pump kill switch so when im not using the gasoline i can turn off the fuel pump. I am thinking about the bin spaces for the tank (in an FB) i don't like having the tank directly behind the driver, but they are very strong tanks and rated for automotive use.

The benefits? Well obviously the price of propane. Its alot cheaper than gasoline, it would be cool to fill up for like 20 bucks instead of 45. I also think it would just be really cool to have something different. Propane runs really clean, really well, and actually, environmentally friendly.

I am still not completely sure if I want to do this or not. It should take some time, and obviously some money, its still in the idea steps so there wont be any pictures yet. I am just putting this out there to see if other people are interested, or if anyone has ever done it. Let me know what you guys think.

Thanks.

~Phill

 

I think its a really cool Idea. Im totally into the trying to find new fuels for my cars. Kepp us posted.

 

a few years back I messed around with it, I could get the 7 to idle fine, but as soon as I would give it the gas it would die. I didn't have anything more than what you mentioned. The timing of the engine does need advanced sincce propane or LPG does not burn as fast as gasoline. Getting the correct air/fuel ratio is going to be key for getting this thing to work.

They make kits for carbs that would make your life a whole lot easier, so I would suggest using one of those.

 

I was working at a rally in Morwell, Victoria, Australia, about 15 years ago and a LPG (Propane) powered 1st gen was competing, it was propane only and seemed to be doing very well.

It was cool as hell

 

I'm pretty sure Mazda powers the Furai with Ethanol.

[/kinda on topic]

 

Bill from B&B Racing claims he can get it running with rotary only draw back he said was, the injectors have a habit of freezing up (propane)

 

i think its a little easier to cut and paste an old post of mine from somewhere else

LPG, impco 225, 13bt
( LPG is aussie blend of propane with a little butane )

i have also helped out on a profire ( standalone vapour ECU ) install
for a vapour injection system on a aussie 85 FB

basically, just your average 225 install with model E simple converter
and a switched air bypass for idle mixes and fast idle when cold
it has closed loop lambda feedback for the converter delivery pressure
and the converter is boost referenced
( trialled various reference techniques including pill and bypass , but works fine with single converter reference line from mixer at boost to 1 BAR )
and the re-graphed 12aT dizzy is modded to GM HEI DLIDFIS, no trailing spark at all

drives AOK, has outperformed petrol FC's at same boost
and returns $25 AUS for 200 km
( tank space limited as my FC tank is in same location as the OEM petrol tank )

- same money would purchase 14L of 98 RON fuel
who here gets 7 L per 100 km from an rx7 turbo???? ( 33 MPG )
( city cycle, hard driven , 10-12 psi )

- aussie LPG being typically 105- 111 RON of various blends


works A1, drives smoother with less unpleasantness than any micro-wreck lobotomy
- at similar power, and much reduced operating costs


pics of LPG FC
legal stuff

this used to be an S5 manifold


A close up
[img=http://img83.imageshack.us/img83/7570/systemcloseup4ne.th.jpg]

DLIDFIS
[img=http://img76.imageshack.us/img76/2537/dlidfis8ni.th.jpg]

the manifold
[img=http://img76.imageshack.us/img76/8796/gasmanifold0dp.th.jpg]

Impco power
[img=http://img83.imageshack.us/img83/914/impco2257jn.th.jpg]



vids of rebuilt extend port motor , with FMIC




the radiator is moved back to get short FMIC piping




http://img507.imageshack.us/img507/67/photo0122hd0.jpg
http://img504.imageshack.us/img504/781/photo0118yl9.jpg




new shoes, and lost the wing
a couple of mm in it, inside and out
245/40 ZR17 sumitomo HTRZ on 7.5 x 17 Advantek escudo

 

FYI ALOT of propane conversions end up making less power then the engine on regular petrol.

 

FYI
only when the foolish person thinks that LPG will run set up as dual fuel with the same ignition curve as petrol


if you expect to hang a restrictive gas carb in front of a petrol TB in a dual fuel vehicle
and not move the timing to suit the LPG
( cause to do so will destroy the motor whilst on petrol )
then you will have a power drop, it will be gutless in either system
( all that weight of two systems , and neither with optimised ignition curve )

- dedicated LPG, dedicated ignition timing to suit
even on same boost and porting, other petrol FC's do not better me

98 RON for the best petrol money can buy in many corners of the world
103 RON for the shittiest 50 % propane 50 % butane mix as delivered in some places worldwide

- for me, usually 112 RON

i would be stupid to think that litre per litre, that LPG has the same calorific value as petrol
you would be stupid if you think you can run 91 or 98 RON petrol to the same level off engine efficiency as 103 or 112 octane LPG

more octane = more boost or compression before knock-point
less calorific value = less power litre per litre of fuel consumed
( even accounting for LPGs leaner stoic )

dedicated LPG systems will show minimal losses boost for boost to petrol
( in power )
but will allow that same engine to be run at higher boosts than with petrol
- even before we take into account the new liquid LPG systems that bring massive latent vaporization boons
LPG has a potential to make more power than petrol , motor for motor
provided you time it right and set the new boost/ compression ceiling limit to suit


- if you don't take advantage of that, your problem

compare LPG with E85 for octane, calorific value , and cost
winner, winner, winner

 

the manifold setup in my old link above moved into a ute on a similar engine with a lesser S trim turbo made 286 rwhp ( DD dyno )
[ i built the engines and the turbos ]