Dean Campbell
I'm not an engine builder,per say. I understand it has to do with overlap in the cam, and how close the water mixes with the exhaust. The farther away the water mixes, the less chance of reversion. If I wanted a muffler system, I would go with the Shot-guns.

There are many things that have to do with water reversion, the first and foremost is how the exhaust system is routed. Some boats that have a deep v, have the motors sitting very low, with this in mind, the exhaust usually goes straghit back or even up in some applications, this is worse than having the exhaust go down to a lower point. If your tailpipes are your highest point in the system, reversion is going to be a problem. Another variance is cam overlap. Cam overlap will cause an engine to have a "vacuum," similar vacuum that is measured on the intake manifold. The cylinder creates a vertex in the combustion chamber and if you have a lot of overlap, when the valve opens, it sucks in what it can find. This will sometimes suck water back from the exhaust, especially on the boats I described. We don't like a lot of overlap because that's wasted with a SC. Air goes in one end and out another!

So yes, I could tell you cams that we've used, we've never done any research on reversion for these hi-perf cams so I can't say it's impossible, but I doubt it, should make great power as well.

Thanks,
Dustin

I'm not sure about this, but my understanding about an increased reversion risk with silent choice type systems is that you are forced to bring your cooling water in the system closer to the exhaust riser, or through it. On my Corsa system, that diversion wye, takes up alot of room between the manifold and transom. It is very close to the exhaust riser and water at that point does not have very far to go to enter the exhaust manifolds. Without the Corsa the water mix would be much closer to the exhaust exit.