Pay close attention this may save you a lot of money. This install is on my daily driver a Mazda 626. It has the FS 2.0 DOHC motor with 180,000m already, most of those on the existing closed loop LPG system. I've done the manifold work with the manifold still in place. Frowned upon because it puts swarf into the manifold but I have done many this way without any issues/damage. Not recommended for your expensive race engine but acceptable for your daily hack.
The best way of starting any install is to study your engine bay and decide where you are going to place the major components. The vapouriser should be below the highest point in the cooling system to avoid air locks. The ECU has to be fixed vertically with the multiplug(s) facing downwards to prevent water ingress. The map/vacuum sensor has to be above the manifolds to avoid accumulation of corrosive fluids. The injectors should be as close to the manifold as possible taking into account that the connecting pipes to the nozzles. Over the course of the thread I will try and cover the significant issues you may come up against. I will also be doing an install on my Civic so that I can provide specific info.
Fast, reliable, cheap. Pick any two - because you won't get all three!
now that I have another Honda in addition to the one I keep molesting all the time, I've almost decided to go balls out and make the test mule run fully on gas. here are some points that I was kicking around. please let me know whether or not they make sense.
1. the reason gas kits aren't popular here is because of the lack of proper control. they are mostly piggybacks which can alter injected quantity at best but not ignition timing. gas being more stable, needs to be ignited earlier like any other high octane fuel. lack of ignition advance from piggyback systems kills throttle response, increases exhaust gas temperatures [burning valves in the process] and wastes a lot of fuel.
2. I, on the other hand, have Honda goodness in the form of a NepTune powered ECU that gives me full control over mapping. I can play with both injection and ignition to my heart's content. so I am thinking of driving gas injectors with the OEM ECU.
3. in case I need to stick to a dual fuel approach, the ECU has *two* sets of maps that can be switched via a predefined input. so I can wire a toggle switch between petrol injector power, gas injector power and the ECU input for the same and use one set of maps for petrol and the other one for gas.
4. gas, by virtue of it being gaseous at atmospheric pressure will mix extremely well with intake air and this mixing will be aided further by the swirl inducing design of the Y8 head.
5. if one manages to spray gas from the injectors at high pressure in liquid form, if should evaporatively cool the intake charge quite well. the holy grail of intake technology.
6. if excessive ignition advance requirement becomes a problem, I could rig up a little HHO kit to introduce trace amounts of hydrogen in the manifold. said hydrogen should ignite quickly and help the hard to ignite gas catch fire with minimal ignition advance.
assuming that all what I've said above are correct, I personally feel it to be extremely stupid to NOT convert to gas.
To answer your questions in order: Yes I'm still alive & well but right now we are flat out in the gas biz. Too busy to eat regularly never mind post! Yes you are making perfect sense. The energy required to to turn liquid propane into a gas is absorbed from its surroundings, producing a significant cooling effect. There are liquid gas injection systems available, Ford pioneered one in the UK, but they have unique issues. Sophisticated car manufacturers ECU's set the ignition advance by utilising a knock sensor, the timing is advanced to take ad vantage of fuel/demand conditions. B series utilise it D series don't. You say you have aftermarket ignition/fuel control, trial & error should produce some interesting results. Hopefully I will finish my thread regarding installation for beginners very soon.
Fast, reliable, cheap. Pick any two - because you won't get all three!
glad to know all is well and that I'm making sense for once.
just a little clarification: I don't have aftermarket fuel / ignition control. both parameters are fully controllable using a modified stock ECU.
the Ds here didn't come with knock sensors though the block has a tapped hole for one. I've improvised my own knock sensor by bolting a GM flat response knock sensor there and running its wires into the cabin and connecting it to the Aux input on my head unit so I can hear exactly what is going on inside irrespective of how loud the exhaust gets. it is an invaluable tool in setting ignition timing along with my ears and brain.
BETEK wrote:Some powerful D-series had knock sensors for example D16Y8, D15B and others.
Also Honda used to have in US market Civic EK (that was called GX) with D-series block that was running only LPG.
BETEK wrote:Of course some D-series had Knock sensors, for example D16Y8
part number 30530-P2M-A01
