stabilizing hydrofoil and trim tabs

I have recently rebuilt a 1969 Reinell, Model 22007 (seventh fiberglass hull of the 22 footer built). She seems to ride low in the stern and won't plane until after about 3,000 rpm.

She weighs around 3,500 lbs and is powered by a mercruiser 165 (chevy in-line 6 cyl 250 cu in.).

Even though it already has bennett trim tabs, will the addition of a stabilizing hydrofoil on the outdrive help her get to, and stay at, plane at lower rpm's and will it help or hurt fuel consumption and top speed?

Also, I've read that it is tough on the cavitation plate and may break it.

I'd appreciate any comments on previous experience on using both the hydrofoil and the trim tabs.

Number 7

Re: stabilizing hydrofoil and trim tabs

Re: stabilizing hydrofoil and trim tabs

I agree , friends don't let friends use hydrofoils . . . Are you putting your tabs all the way down to start off? If not, you should try it. 3000 RPM to plane a large boat with a smaller I/O is probably normal.

Bennett Op Manual

Re: stabilizing hydrofoil and trim tabs

i agree alotta boat a little power. tab all the way down. i have 2 or 3 set of foils in the shed i've taken off. don't know why i keep them, maybe to give to someone i don't like.

Re: stabilizing hydrofoil and trim tabs

Hello - I have a 225 VMAX HPDI and considering to install a hydrofoil to keep the bow down for take off and to keep the boat more stable in rough water. From reading your threads, I should not?

Re: stabilizing hydrofoil and trim tabs

Re: stabilizing hydrofoil and trim tabs

kevini said:

Hello - I have a 225 VMAX HPDI and considering to install a hydrofoil

Click to expand...

Kevini,

If you do I will hunt you down and . . . oh, never mind . . . just take a look into trim tabs, helm adjustable or SmartTabs, before you bolt anything to your perfectly good OB

Re: stabilizing hydrofoil and trim tabs

Number7,

Since the boat alraedy has Trim Tabs installed adding the foil would be counter productive. When Trim Tabs are installed they can be used to adjust the boat's attitude and the power trim on the outdrive can be used to trim the prop for maximum RPM. Properly sized Trim Tabs should produce all the lift you require to trim the boat through a broad range of speed, loading and sea conditions. The foil will only contribute additional drag.

If you feel you need more lift (i.e. be able to plane a lower speeds or with more weight aboard) take a look a the size of your Trim Tabs. You should be using at least 18" x 9" or 12" x 12" Tabs. Going to a larger size Trim Plane will often make a world of difference in the way the boat runs. The larger Trim Tabs will allow you to hold the bow down at lower speeds. This allows the sharp forward sections of the hull to cleave on comming chop, reducing pounding. Also the larger Trim Tabs will give more lift for less drag since they will have to be deflected less then the smaller Tab to produce the same amount amount of lift.

I hope this helps,