Diesel Motor LPG Misting... bit of a vapour project

[De Ranged]

Had a cool night, just me and my oil technician mate bouncing this idea around

solved the injector lube issue lol was simple as.... should have seen this one, given I have compressed air at the shed... a compressed air inline oiler, now before you go off about burning oil, in the oil industry they class a motor as an oil burner if it uses 200+mls per 1000km

If we setup the oiler to say 50mls per 1000kms we could probably get away with half that.... next to improve on that use trans fluid instead of airtool oil, it has the same viscosity but has seal conditioners in it... and its something I'll have since its in the power steering and the auto trans

After that we started throwing around MS vs a cheap car ECU, the fact the MS can take the input from a wideband O2 without modification of the signal.... given the cost of MS vs a ECU & frequency modulator that can be programed, we are on a par so why not go MS as I can program the knock sensor into it. To use the knock sensor on an ECU we were looking a seperate board to monitor dwell so as the ECU retards due knock we can use this to cut gas flow, coding is alot easier lol

This brought up the problem of coding.... I can create a routine but to use the sensor as a trigger I need to know what sort of signal to set as "on" we both know how the sensor works... the frequency of the vibration of pre-ignition is different to normal ignition so the sensor responds..... but does it send a constant signal and is frequency based, a timed pulse per ignition and knock is out of timing, sends a positive "live" feed when knock or the opposite a constant positive with knock cutting the circuit.... I kept saying "I want an on off signal to work with..."

We were getting to the state of pulling one out and hooking it up... to test, so we wander outside to see if we can pull one out of a wreck, looking at it is going to be a mission... thats when it dawned on me... all we need is a signal to turn something on or off, why does it need to go through the ECU I can achieve the same thing with the sensor direct to a gas cut off valve.... so we run the two systems, knock wins since it cuts gas flow

[xychix]

A diesel tends to burn with circa 40% excess air anyway. Even with thick black clouds of smoke out of the back you still have excess air.

The way I've seen this set up on an automotive engine before is by using a trigger on the throttle pedal. Once a certain throttle position is reached, LPG is injected.

I'd also be wary of introducing it at the turbo intake - that's a lot of potentially combustable air/fuel and if it ignited then you might have some excitement. I'd work out a way of introducing it into the inlet manifold.

So the hole for the EGR valve finally gets a meaning :) I knew it was where for a good reason.....

[dirtyninety]

I think your massively over complicating what can be a very simple system.

Some clever valving, and a solenoid can give you the desired results.