Chine Walk

[aussiebasser]

Hey guys,

I've been doing a bit of tweaking with the old 285/Verado. I've got an 8" Bob's Hyd Jack and I'm running a 26" Trophy plus. The computer may or may not have been a bit tweaked (which is legal down here). I finally got to give it a good run on dead flat water with less that half a tank of gas and not much weight. At 6420rpm she was pulling 65.2 mph on the GPS. (19psi water pressure) The chine walk started gently as a slow rolling from side to side. I tried to steer gently into it, first to the left and then to the right, (I couldn't remember which way I supposed to do it) but nothing helped. It kept getting worse, to the point of it being undrivable. I trimmed in a little and it stopped. Could this be curable or should I just live with 62mph. I think the dead smooth water may have had something to do with it. I have a friend with a 175 Verado running a 27 Trophy plus on a newer 285 who is getting 70mph on salt water and I was hoping to match him.

[ditchdiggerjcfII]

If it is fast, it will chine.

[big_b16]

Easiest way I found was to trim it up until you're just starting to feel it fall off to the side, then put it into a gentle left turn. Once I start actually moving that way off the pad I let it out a little bit to the right. I think I'm just offsetting the engine torque but when I do this, I get very little to no chine anymore. The feel came to me after about 30hrs of seat time. At the beginning, I had no idea and just drove it under control until I got the feel of the boat running on the pad. Good luck.

[dezracer1466]

I chine my boat everytime I take it off the water.

[Jimboat]

aussibasser - Your situation sounds pretty typical for a performance vee hull.

Chine walking can arise with most high performance vee-hulls. As the hull accelerates, lift increases and the wetted running surfaces that are required to support the hull are reduced (more Speed = more Lift = less Surface). As the speed increases throughout the velocity range, the hull often gets to a point where the lifting surfaces become very much reduced and the hull is now “balancing” on a small area of the vee-portion or the “vee-pad” of the hull. When that surface becomes sufficiently small, it becomes very tricky to “balance” the hull on its vee or pad. If left unchecked, the boat will rock from side to side with increasing drama. This is because the boat is now “inherently unstable” – meaning that if left alone, the “imbalance” of the hull is more likely to get worse on it’s own, not better (the worse it gets, the worse it gets). If it gets out of hand, you can get into real trouble!

With some driver input, the condition can be stabilized. With changes to hull setup and/or changes to the driving technique the condition can be alleviated.

Some established steps toward minimizing chine walking are:

1. Check & adjust steering
2. Use solid mounts
3. Clean Hull Lines
4. Weight balance of hull
5. Motor height
6. Propeller selection
7. Seat time (experience)
8. Minimize Trim Angle

For more details, check out this thread on Chine walking

Also, see full article on "Chine Walk"
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[bigfin]

Aussiebasser I had Steve Morgo's old 285 with 150 etec. Nothing special but with new raker prop and 6" jack plate was seeing 105km's 65-66mh and no chine walk all day everyday.

[aussiebasser]

Thanks for th einput everyone. I'll keep playing with weight distribution and seat time.

[aussiebasser]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bigfin &raquo;</TD></TR><TR><TD CLASS="quote">Aussiebasser I had Steve Morgo's old 285 with 150 etec. Nothing special but with new raker prop and 6" jack plate was seeing 105km's 65-66mh and no chine walk all day everyday.</TD></TR></TABLE>

Well Tasmania isn't big enough to have enough fresh water so I'm thinking you're running in salt, and your boat will be faster on salt water.

[bigfin]

Was only 2 mh slower in fresh mate.

[dr. seuss]

religously