[Christ]

Frank - I'm not saying poppet valves are a bad thing, I'm saying exactly the opposite. There are obviously gains to be had from modifying the flow tract available with poppet style valves, but there are also other redesigns that would please the wallet and engineering minds much more.

theunchosen - The total exhaust package on my Caravan actually looks something like a teardrop when viewed on a single axis, even given that the engine sits relatively high in the engine bay, and the initial exhaust pulse happens perpendicular to the ground.

For lack of imagery, consider how an upright inline engine is normally oriented, then imagine that the normal exhaust manifold exhausts fumes at about -20* to the flange surface of the head, where exhaust continues to flow mostly in a straight line, until there is a 20* bend (-20 + 20 = straight) which continues almost the length of the van.