hello CDS70
please dont get me wrong, both the C12 and the V12 engines are very good engines and will continue to be for many people, but as a manufacturer we need to offer our line thats competitive with our competitions engines.
the sales of the side exhaust C12 engines is almost zero, i can tell you that this year here in the USA we have sold very very few of these, but then again there really isnt a big class for use of these engines.
for the v12, it has been the workhorse .12 in our line up for a number of years now, but as with any engine, it was time for a facelift and so came the birth of the R3.
the numbers of C12's and V12's left in the inventory is still a good number but i think people should know that eventually the engines will be discontinued and phased out.
we have always tried to do our best to support any engine of ours that we have produced,so the replacement parts should be available for quite a while but the reality is that eventually you should pick up another motor if you are looking for motors to replace your older ones.
if you are in need of parts or the engines themselves,
www.amainhobbies.com has always done a great job of stocking these and many of their replacement parts
hope that helps
regards
kevin @ RB USA