Yes I converted Andy's Aircooled many years ago and he has never had any problems and as stated mine has done over 300,000 miles 2/3rds of that on lpg with out any problems, I have of course rebuilt the motor once in that period but you'd have to do that anyway and I know how to look after it too.
As for softer seats of the early 80's all of the vehicles had hardened valve seats from the early 70's onwards, bay, beetle etc and I've converted loads of these, if you are worried about the extra heat in the engine then have a flashlube system fitted, this lubricates the upper cylinders and takes the place of the liquid fuel. The flashlube system is fitted as standard onto anything japanese, american, ford or vauxhall because of inferior materials used in the engines compared to german and swedish engineered engines.
On the other hand and it is not just the Aircooled that burn out valves, if the vehicle is not in top condition, well serviced (and I don't mean plugs, air filter and oil changes every so often) I mean properly serviced by a decent garage that can foresee any problems and setup mixtures, balance carbs and have the correct diagnostic equipment then yes you will burn out any engine. LPG runs at a higher combustion temperature and if for instance the bottom tins have been removed from an Aircooled vehicle it cannot remove the heat efficiently and valve seat recession will occur, I can advise on that when I inspect your vehicle, similarly the water boxers, if they are not serviced correctly and have a tight valve or air leak at the manifold or tend to run weak because the mixtures have not been checked annually then yes it will burn out, but this applies to any engine.
Just a little more care and attention to the servicing needs of your vehicle will make it last many many years, mine is 30 years old this year and I cannot foresee it ever leaving me or scrapped, if you are in doubt please talk it through with your chosen installer first and of course I would be more than happy to answer any questions.
Sorry but some people talk a right load of crap about these conversions and it is pure ignorance more than anything, petrol or lpg if an air cooled does not have its tinware and is running weak then you will get valve seat recession, japanese motors do have hardened seat but the valves are crap so they stretch due to the extra heat, same with f.o.rds, vauxhalls are just crap material they just burn (and deservidely so
) so yes we are aware of the higher combustion temeperatures and now you are and you know now what to do about it, the flashlube system is the only system that puts the correct additive into the inlet tract, we also use the flashlube on non-unleaded engines so they can use unleaded fuel.
LPG is the only current modification you can do to your petrol engine to decrease its environmental impact dramatically, the only system that will pay for itself in an average years motoring and provide you with genuine fule saving thereafter, the only downside is tank location and the need to have the vehicle serviced correclty.
Edited for spelling
