Some Really Dumb Questios I'm Sure !

[milmat1]

Re: Some Really Dumb Questios I'm Sure !

How planing works:

You need a planing hull. You have one.

You need enough power. You appear to have it.

When you accelerate, you create a bow wave. You are pushing through the water. You might say 'plowing' the water. Ok. Non planing-hulled boats just keep pushing the bow wave. They just displace water and push through it. They can't build enough speed relevant their size to climb the bow wave and plane out.

As you build speed, you climb up and onto the very bow wave your hull just made, once on the bow wave, you need a little more time or oomph to get over it. You should 'feel' the boat get over it. Engine sends signals too, and you will be able to scale back the throttle and settle in as you are now at planing speed and can run from low-cruise speed to mid-cruise speed up to top speed as you like.

This whole series of events -- known as 'time to plane' -- can be done in as little as 4-5 seconds or up to 15 seconds depending on hull design, power-to-weight ratio, prop size/type, engine trim setting and other variables.

That was a great explanation ! Thank You..

And that describes exactly what I feel when taking off.

Another Question, My boat does not have a power trim, So If I move the motor stop pin towards the boat does that tend to make it plain soon or later? And by not having a power trim I assume there would be a trade off in top speed or stability etc..?


THANKS TO ALL FOR THE HELP !!!!

 

[Philster]

Re: Some Really Dumb Questios I'm Sure !

I had a boat for 15 years with an outboard and no trim.

Moving the lower part of the motor close to the boat limits top speed. It keeps a good chunk of the hull wet at higher speeds. This is resistance.

However, the set up you want gets you going with the bow mostly down, so that you are not riding around nose in the air unable to see. The focus isn't really on top speed.

So... lacking trim, you are probably sacrificing top end. You willl have a nice puttering ride, nice time to plane and even a decent cruise. But, since you can't trim out (up), you can't get the last amount of the hull out of the water.

If you get a trim setup, you might need a different prop, because the engine will be able to rev more (over rev) when you trim out (up). Depends on what she does right now with the throttle wide open. If she redlines now, with a the ability to trim, she'll over rev. This would say: BIGGER PROP... which adds a touch more top end and knocks the revs down a bit.

 

[milmat1]

Re: Some Really Dumb Questios I'm Sure !

AHHH!! OK !

So my next job is getting the TACH working Correctly !!....LOL

Thanks Again !!!