Now I am confused!!  Let me start again and where I am coming from is the everyday builder that may consider a rotary over a Lyc.

Price and time will dictate in most cases.  Lets start with a second hand Lyc  $30,000  That gives "wriggle room" on a rotary of say $15 - 20,000 ready to go.

$10,000 for an redrive and ECU does not leave much especially if it is a single rotor.

I really like Lynn's suggestion of fixed ignition together with a Rotec carby,  Carby $600 USD and fuel is mainly done together with the ability to control mixture via the carby.

THat leaves ignition   NO matter how I look at it with any sort of of ECU it takes little to get to say $2000 -- if you have some idea about computers -- I don't!

What is actually necessary  with a simple ignition?  MY choice in order is  Spark and timing. RPM,  A/F ratio,   Engine and oil temp and pressure , Battery voltage.  Then whatever turns you on as anything else is not critical to flight or engine health.  I realise that the sky is the limit here but all cost money to be balanced against the Rotary vs the Lyc.

Suggestions??  Remember I am computer illiterate. I prefer to say I was born too early rather than I am totally stupid!!  Price will sway people to a rotary rather than "lovely" gadgetry that cost a lot of money.

Neil Unger.