LPG

[Dodo Bizar]

Hmmmm.... taxes on the car will increase with 60 euro each month. Not doing so much km (aming under 15k per year) I need around 190 euro of petrol now per month, assuming I can get 1:12 l:km (not sure that IS the case). My guess would be gas will cost me around 125 euro assuming 1:8 or 1:9. So... without install I'd be brake even. Then there will be a lack of time since I want to work on the EJ9, not other cars. Always work on others cars make me neglect the EJ9 .

[hondamake]

Hi guys sorry for the long silence, just when the quiet life was getting comfortable all hell broke loose! As well as my day job I've also been selling autogas rigs on eBay and supervising LPG installs/remedial work on a big variety of vehicles. In the last 6wks I've been under the bonnet of:- Merc CL500, Toyota Landcruiser, BMW E28, Transit and Transit Connect, LDV truck. I'm about to convert a Chevy day van. Not to mention my own cars! Speaking of which I've just killed my D16Y7 engine (again) this time I'm taking the opportunity to install the D14A4 along with some nice trick parts I've collected together. Mr Pardizzle provided me with an inlet manifold and re-profiled cam, bargain - thanks Tom. Hi Dodo, do you have to pay more taxes for the use of LPG, can you not find a propane supply off the books? The propane in your domestic tank is identical to the propane in your car tank.

[007]

@hondamake, I had a question:

can LPG injectors be used to inject water without packing up in the long run?

[sktaroins]

i need to put a post here so i can manage to see my posts and follow up.
ill need to know how to do it too
Thanks
sam

[jangz]

hahaha lol I'm posting this comment here also as I too need to keep a track of this and really wanted to learn the exact steps to fit an LPG to our D14 Civics.

Could you (hondamake) do a proper walk-through with pictures as this would kinda be exclusive to dodo-upgrades because i cant seem to find a good tutorial anywhere regarding this and your knowledge would be cemented here, it would be nice to learn or see how each component is connected even if it were a 1, 2,3 pictures of each part leading to what part to then mimic the same setup and also the kit that is recommended.

[hondamake]

Hi Guys, I'm in the middle of replacing my old D16Y7 motor with a much lower mileage D14A4. I'm going for a better inlet manifold but incorporating my original throttle body so that I can retain the kick-down cable quadrant for my auto box. I'm installing a closed loop LPG system from my parts box as a temporary fix so that I can get the car back in use. I've described this system in an earlier post but basically it uses a mixer ring to introduce the gas into the throttle body. The flow of gas is modulated by a simple ECU that monitors RPM, TPS and lambda signal. I've started taking photos to post to give you some ideas to consider. Eventually I will install a full sequential gas injection system so that I can compare results.

[hondamake]

I can see no reason why gas injectors could not inject water, they're just a solenoid operated valve. The nozzles are installed in the manifold by drilling and tapping 6M x 1.5 threaded holes. You would have to supply water under pressure and a means of triggering the injectors. Water injection is not something I have any knowledge of, I know why it is done but not the srategy employed. Does the water have to be injected in sequence? Is it only introduced under certain parameters, RPM, TPS, temp etc?

[007]

I want to inject water exactly like fuel. one injector per runner and the signal piggybacking off the fuel injector pulse so that I have a constant fuel:water ratio by playing with water rail pressure and injector nozzle sizing. a friend here had used fuel injectors for a DIY water injection project long ago but he reported that the injector jammed pretty quickly, possibly because water is more corrosive / less lubricating than fuel. hence the question. LPG is also not a good lubricant from what I hear, so maybe the injectors will work reliably with water too.

here are some schematics I drew up:
http://blackworks.in./cars/resources/wiring/wiring.png
http://blackworks.in./cars/resources/wi ... verbox.png

[hondamake]

With a petrol injector the liquid passes through the centre and the volume injected is controlled by the duration of the opening time of a needle valve. LPG injectors are handling saturated vapour, not liquid, and volume control is again by duration of opening time but the valve does not need to be so precise. LPG injectors normally have a very simple rubber faced valve which covers/uncovers the outlet down to the inlet manifold. To put it in perspective I can see why a petrol injector would corrode internally and fail, but the control mechanism of an LPG injector has no exposure to the liquid it is passing. The best comparison is an old fashioned kitchen tap with a rubber washer. The problem would come with the strategy that the LPG ECU uses to control the injection. When you switch from petrol to gas the LPG ECU shuts down the petrol injectors but uses their pulse signal from the car's ECU to control the gas injection. You would switch your water system on and the engine would stop. I will try and find an injection system that uses stand-alone emulation so that you can trick the ECU into thinking that it's running on gas not petrol.

[007]

if the gas injector keeps the fluid separate from the moving mechanism, it will be perfect for water too.

regarding control strategy, I will not be running the water and petrol injectors in an "either / or" mode. think about it like an inductive clamp around a spark plug lead. the timing light signal piggybacks off the spark plug pulse for duration but the actual power is drawn through a dedicated battery connection. same here. I will tap into the injector lines and use very little additional power to drive a transistor which will amplify that pulse and power the water injectors. so the ECU drives the fuel injectors and provides a reference to the water injector drivers, thus operating both of them in parallel. with the open times being identical between fuel and water injectors, the flow ratio comes purely down to the ratio between rail pressures and nozzle sizes.