Semi-V bow lift yes or no?

[omcstratos]

I have watched numerous videos of fast jonboats. This one is one of my favorites, http://www.youtube.com/watch?v=SaLb0-y0Fvg.

The question I have though is do these boats run a high bow lifting prop or a transom lifting prop. I have run one of Ron Hill's thru hub cleavers and the boat porpoises so bad you can't drive through it even trimmed down. I always thought high rake and bowlift were for v-pad bottoms but does that work well on jonboats too?

[omcstratos]

Anyone want to throw their 2 cents in? Don't know if a cleaver style or chopper style prop would work best on a flat bottom boat.

[HankFrazier]

I have watched numerous videos of fast jonboats. This one is one of my favorites, http://www.youtube.com/watch?v=SaLb0-y0Fvg.

The question I have though is do these boats run a high bow lifting prop or a transom lifting prop. I have run one of Ron Hill's thru hub cleavers and the boat porpoises so bad you can't drive through it even trimmed down. I always thought high rake and bowlift were for v-pad bottoms but does that work well on jonboats too?

We SRG run flat bottom and semi v jon boats we run nothing but cleavers they work the best for us. they have plenty of bow lift. some jon boats are very hard to get to set and run with out porposeing their are some things u could try.

[HGipson]

Hank, What all can be done to stop the porpoising at high speed on a Semi V jon boat ? Got my motor on a jack plate cavitation set level with bottom. 60 Etec on 1546 Alumacraft. Been trying to find some answers to get it back down so I can get more trim an speed out of it

[HankFrazier]

Hank, What all can be done to stop the porpoising at high speed on a Semi V jon boat ? Got my motor on a jack plate cavitation set level with bottom. 60 Etec on 1546 Alumacraft. Been trying to find some answers to get it back down so I can get more trim an speed out of it

send me some pics of your setup and i'll try to help.

[BRzuki]

I wouldn't waste your time. I've told him countless times over the last 4 or so months how to fix his boat to sit back on its tail and run out and he has yet to try anything I have told him.

[HGipson]

Yeah he told me to take a hammer and block of wood and beat a hook into my hull. If that's what I gotta do Id rather just have a crappy running boat

[BRzuki]

Yep...I haven't slowed a boat down yet doing that either.

Also said to try a low rake prop instead of that 20+ degree raker, weld trim tabs on the back and adjust them accordingly, put a higher pitch prop on and see if the increased speed will settle the nose, or at the very least try to trim through the porpoise....

[Fastjeff57]

How about adjustable trim tabs? I use a Lenco electric cylinder to adjust the porpoising out of it (for comfortable cruising). THe tabs are pulled up for speed runs at a touch of a switch.

Jeff

[Smokin' Joe]

Yeah he told me to take a hammer and block of wood and beat a hook into my hull. If that's what I gotta do Id rather just have a crappy running boat

Get a straightedge. Does the running surface have a rocker? Take it out.
Square the trailing edges at the transom. I now have new props available
for the OMC 2 cyl and 3 cyl loopers, castings OMC made for EP/SE
earlier. These are the trick.