Anti-Ventilation plate height

[marops]

Hi All,<br /><br />16' Zodiac (F-470), 55hp Evinrude WRL, Tiller.<br /><br />When lining up the anti-vent plate to the bottom of hull, is it best to err above or below hull?<br /><br />I mounted a laminated plwood transom behind the original transom to raise the engine up a bit. Now the anti-ventilation plate's forward edge is 5.5" behind original transom and lower unit forward edge is 6.5" behind.<br /><br />I'm still getting quite the rooster tail on either side of engine when underway at speed.<br /><br />Anti-Vent plate is now about 1/2" below hull. Should I raise it, or do I need to fill in that space between transom and leading edge of engine?<br /><br />Thanks

 

[LubeDude]

Re: Anti-Ventilation plate height

As a quick guess, I would say you need to raise the engine 2 1/2 ". 1 " above is a bood place to start, plus another inch for the setback.<br />---------------------<br />

 

[DJ]

Re: Anti-Ventilation plate height

Better to err on the high side, ESPECIALLY with a set back engine.<br /><br />Leave the set back and raise the engine. I would start 1" above.<br /><br />A roostertail is indicative of an engine set too far down.

 

[marops]

Re: Anti-Ventilation plate height

I didn't know that as the engine is mounted further aft, it needs to be raised.<br /><br />Dang, funny how you don't realize these important things until after you've finished your project (raising height of engine).<br /><br />Okay, I'll start with an inch and go from there.<br /><br />Thanks!

 

[Hooty]

Re: Anti-Ventilation plate height

A rule of thumb for rigid non-inflatable boats and setback is one half inch up for every inch of setback.<br /><br />c/6<br />Hooty