Yeah, it can badly damage vane. But there is solution as well. I have seen 3A with rubber valve created on top of intake manifold, in case if there is backfire, it will let it escape, otherwise negative pressure will keep it closed. I have heared about funny solution for V6 with cheap LPG system as well - in intake manifold drilled large hole, which is plugged with plumbing plug, in case there is backfire, it's out
only engine stalls as well
Well, I know one guy, who is using 1986 A100 with KU engine and LPG without problems - but it's k-jet and not ke-jet
