The other problem, as anyone who has ever cranked the boost on an RX-7 knows, is that rotary apex seals really don't like the high pressure and violent combustion that pinging gas engines and perfectly healthy diesel engines see. This may be manageable in a tank engine with bigger, heavier seals and bunker oil pumped into the combustion chamber to lubricate them, but there aren't any emissions standards for tanks.
Q. Pick-A-Part University
I can't, for the life of me, visualize how a dual overhead cam engine with rocker arms works. I can see how an SOHC works with the cam in the middle, activating the rocker arms for both intake and exhaust. I've even seen how a dohc directly operates the valves by way of the bucket tappet. But I cannot get my head around how a dohc works with rocker arms, like in the 4G63. I can't find any movie clips on YouTube or anything. I've checked books and magazines, and can't find a visual layout for this. I guess the easiest thing to do is grab an engine and see for myself, right? Problem is, I'm broke, so I can't. And no shop will let me see. Please help me.
Lawrence Chaw
Grand Island, NE
A.Give a man a fish and you feed him for a day. Teach a man to fish and you feed him for a lifetime...
Turn off your computer, scrounge $2.00 for the entry fee, drive to your local self-service junkyard and educate yourself. You will learn more about how stuff works in one day at the junkyard than you will in a week of sitting on the toilet reading my answers.