Now this is an aero head <iframe width="420" height="315" src="http://www.youtube.com/embed/TS5AxbQXdY4" frameborder="0" allowfullscreen></iframe>
Always fascinated that the power take-off (gearbox) is at the nose end of the engine that we all know so well..... but there are a lot of ultralights out there powered by R100 engines... makes sense, when you think about it!
The power take offs on the rear of the engine in the video (look at the oil filler) The heads are on back to front.
The one above appears to be at first glance due to the headers coming off the engine, but look closely. You can see the oil filler and timing plug on the same side of the cylinder as the headers !?!? They must've done some big time modification on that engine. That means they're using a left side head on the right side and vise versa. It also means they must've ground a custom cam to make that work. Yikes. Crazy shit.
Chris, what's your take on how they did this? They must be using a left head on the right side and vise versa, but they would've had to grind a custom cam to make this work, right?
I wanted to do the same thing to a motor for my chopper build so I found the company that makes a new 308 cam for the 79 motors and yes they flipped the pistons and heads left to right.
Theres an article here on Aero conversions. Nothing about reversing the heads though http://www.esatclear.ie/~xair/conversion.htm
As long as the cam profile is the same for intake and exhaust, you should be able to just put the cam timing 180 out.
MMM, no. You'd still have your intake openning for the exhaust stroke and your exhaust openning for the intake stroke. Putting it 180 degrees out won't change the sequence. That engine won't run.
Places like Mega Cycle will grind custom cams to the customers spec, to accomplish things like this. Years ago, I realized my GSXR1100 had to cylinders at TDC, at a time, and a wasted spark (like most every other inline 4) I thought it would be fun to have the cams ground so the bike would fire two cylinders at once. This way I could have "twin cylinder bike" just for fun, and the confused reaction to the sound of it. I decided it would be hard on the crank, etc. having two power pulses at a time, so abandoned the idea.
That's called a "big bang" engine. It was a semi-common thing to do with brit twins for dirt track racers. Some of ducati's desmosedici V4 factory racers had big bang engines that basically acted like a v twin. I'm sure somebody's done it with an inline 4. Someone needs to make a big bang airhead. All you'd need is a cam. Who's gonna do it? It'd be a 1000cc thumper. Talk about a tractor! I can't imagine it would last long, but oh what a ride.
Yamaha R1 had the Big Bang motor a few years back, which had 2 cylinders firing at the same time much like a twin. It might even be still current. Have a flatter sound of the engine. On the Airhead Aero motors, they cams are reground with the lobes reground to suits the reversed heads. You can buy them out of the UK.
