medium cam na small block has thru prop now. want a compromise between the 2.

I would be to concerned about reversion and moisture, as the motor cools you are going to pull moist air into your cylinders. I've seen what that can do $12,000 later, not for me. I use the Gibson clamp ons, they sound great quiet enough to keep from getting a ticket and yet when I get a slacker on the river ahead of me a little burp on the throttle really wakes them up.

I think this moisture thing is overblown. Obviously getting any boat out of the water when not in use is preferable. But for day to day use, I don't see how the turn downs would be any different than through the hub/prop in an IO, whether it was a blown monster or stock package. Small breather holes on the top side could be drilled to eliminate any "alleged" suction issues.

thought of a freebie way to try it out. clamp the riser hoses and elbows from thru prop on the back of straight tips. once again; under molded swim platform...

Seems like I have seen some of the guys on this forum talking about their "Home Depot" turn downs using PCV piping - mostly to get around running around in heavily patrolled areas for a short time. They actually used the rubber boots and clamped them onto the exhaust with a set of 4 inch PVC going into the water. Sounds crazy, and haven't tried it myself, but just know I read it on here years ago. Might be a good way to see how they perform before spending the coin on a "real" set of turndowns.

I agree with the previous poster that I can't see how reversion or moisture could be that much of a problem as long as the water is mixing in near the transom. I guess you could always pull a riser to check.

Ahh any motor with dry exhaust gets moisture in the cylinders weather you think it does or not. The valve seats also get rusty it's the nature of a boat motor. As soon as you fire it up the rings clean of the cylinders and the valves clean up the seats. That wouldn't bother me a bit the only thing that would bother me is the complete and total gayness factor. Behind platform or not of the boat is on the trailor and someone climbs underneath its still gay. Just the thought of my boat sitting in the driveway with turndowns on it... Gay

Have not used them yet, but here they are.

I always thought that those big of turn downs were to help airate the water when getting on plane???

As Jerry Seinfeld would say... "Not that there's anything wrong with that."

Great idea if you ask me.