by metalworker0 » Wed Jan 26, 2022 6:32 pm
I'd say the pinto engine is highly suitable, i ran LPG on a sierra for 14 years, but i did have the special valve seats put in and did a full engine rebuild before the conversion.
Because of the octane adjust plugs ( these are blue and red connectors found dangling at the side of the coil)i could set timing right for it ...and had switches connected to the plugs, to put it back for running on petrol. because i could adjust the timing, i made full use of the gas, taking advantage of its higher octane ...it was slow because it was on a Groot mixer system and low energy density of the fuel...but was prepared to put up with that as i was getting plus 35 mpg on LPG, at the time 35 pence per litre when petrol was 80 - 90 pence a litre
The only problems i had with it was the carb drying out (Pierburg 2E3) and buggering up accelerator pump diaphragms etc - also went through ignition leads every 18 months.
You do need to close the gaps on the plugs a bit, the ignition has to be spot on and well maintained - high quality plugs leads needed, other than that it was all good.
NOTE - valve seats have to be changed because the originals are cast in the head .....made of cast iron, so vulnerable to wear caused by the dryness and non lubricating properties of LPG. The old valve seats are machined out to provide a space for the new hardened seats. you cannot get away with not doing this ..its
far worse than running a car meant for leaded on unleaded...it will pocket the valves in no time ...this will be seen as valve gaps closing up after a short period of time ..then the valve seats will burn because the valves will be slightly open. results in low compression, back firing , popping in the exhaust at first.
So hardened valve seats are a must do - or don't convert!
All the best.mark