I turbocharged the first RX7 back in 1980 and it screamed. I knew they had problems with the Apex seals, but have since fixed that. Old RX3 were nasty oil burners. I like the concept of the motor, whereby, fewer moving parts. Yes the Cat does take care of the byproducts from the cycling of the motor. I have seen some of the cats get red hot from use. Bit of a fire hazard to say the least. All in all, the motor does have the potential to someday do as was intended.

Saab engine had block split in two. Pistons moved in upper part and crank in lower. Block halfs were joint together on one side with large hinge and had adjustment which moved up and down on other side. Result was that compresion chamber size got smaller or bigger while stroke lenght remained same. Problem was heavy gage hinge and adjustment mechanism needed to make them stand compression cycle loads.

http://www.saab.com/main/GLOBAL/en/v...mage/img02.jpghttp://www.saab.com/main/GLOBAL/en/v...age/img_03.jpg

http://www.saab.com/main/GLOBAL/en/v...mage/img01.jpg