It's probably worth pointing out a few things about the record
holder, mostly that properly set up it only turns left unless you're
lusting after real excitement and that it runs that fast because it
runs almost entirely free of the water surface. It's a narrow
specialty item that's only good for one thing, but it does that
really well, and in APBA racing it could likely outrun it's piston
engined counterparts in nearly every contest.
Most outboard hydroplanes are tail-draggers to some extent due to
motor weight, but this one's based on progressive variations of the
layout the designer's grandfather Ted Jones and Boeing model maker
Hugh Entrop that began sometime in 1952. At that time Outboard hydros
featured narrower afterplanes..Sponsons easily pushed the front up
and trapped air flew the front of the boat. Ted and Hubert started by
putting the driver in the bow to balance motor weight, then began
reworking the trap and bottom profile. By 1958 Hugh had come to
dominate F-Hydro with a hull that featured a full width bottom from
trap to transom that distributed trapped air uniformly the length of
the hull. With about 6º of tuck this boat became a prop-rider and was
the first boat to break 100 mph with a market outboard. Before his
retirement Hubert's hulls carried the straightaway record above 130
mph. Ted's son Ron Sr. began designing and building outboards, and
when, in comparing lap speeds, he saw that some of his outboards were
turning laps comparable to or faster than his conventional inboards
he reworked his inboard designs to incorporate elements from his
outboards to revolutionize the category. Ron Jr revolutionized
inboards again with incorporation of carbon-fiber components and
design changes based on wind tunnel test data on the Miss Budweiser
Unlimited hydro.
In the case of this particular boat, it's the third of three built.
The first and second were the design-mule and the current D-Stock
hydroplane that testing and reconfiguration led to. Mike's Hydro was
the third. The standout difference between this design and all the
rest is that the design incorporates a lot of Ron Jr's inboard
elements. The hull's entirely carbon-fiber composite, and in place of
the sharp sponson tips and chine edges seen on nearly all outboards,
this one features blunt sponsons with rounded edges that make air
travel a greater distance to slow its passage and limit it's ability
to grip an edge or seam...It doesn't slow the boat, but it does make
the hull less reactive, so if the boat begins to lift or get out of
shape at speed the driver has time to catch and adjust to save it.
In operation, this boat distributes air better than most, allowing it
to prop-ride with only a couple degrees of shaft angle, allowing the
hull to fly on the prop-tips about an inch or two above the water
surface at speed...Nearly no drag and most of the prop power is
devoted to thrust. Nearly all D-Stock outboard hydros are designed
for a top speed of about 90 mph, but Mike was past that speed in
about the second week of testing. Bob Wartinger (who holds the record
for setting waterspeed records at something over 230 records) spent a
day making ride/balance adjustment's and sorting through props for
Mike to test. Bob picked a 4-blade that he felt offered stability. In
the kilo the boat was coming off the traps at about 104 mph just
starting to wiggle at about 15 mph over the D-Stock design speed,
thanks to Ron Jr's aerodynamic magic.
Their are a couple unique things outside of the design that brought
about the dramatic increase in speed. One is that Mike incorporated a
gearbox to increase prop rpm. In a direct application motor rpm and
gearing limit prop rpm to about 5,000, but the step-up box brings rpm
to the 9,000 to 11,000 rpm range where these surfacing props are most
efficient. In the past we relied on propellers with huge pitch
designed for the high torque cast-iron Johnson and Evinrude PR motors
of the '30s. The other big step forward was the move to lithium. Lead/
acid gave good power, but density was low and the weight of a 12
battery pack mostly ensured drag by sticking the boat to the mater.
Rather than use blocks packaged batteries Mike used single cells
singled up in 6 packages to produce 132 of the 144 volts allowed with
a weight penalty of only 80 pounds in place of the 500 of lead/acid
and distributed the weight equally for balance. The pack could power
the boat through 4 to 6 full kilo passes, plus it had the surplus to
allow the step-up gearbox.
Returning to the top, I noted the boat was good to go for left turns
only. That's because it carries a large turn-fin on the left side. In
a kilo It helps keep the boat stable, and anchors the left sponson
during the turn-around for the return pass. It's on the left side
because races are run on counterclockwise courses. When you turn left
at speed the boat hangs on the fin like a kid stabilizing a
downstairs circular staircase run by hooking the bannister. When
right at speed the boat rolls up on the fin to spit you out.
On Dec 31, 2012, at 5:37 AM, james4078 wrote:
> I was going through some of my contacts and wanted to pass along
> some information for you guys.
> Pure Water craft has made some alterations to their out drives and
> is getting ready to market it. Here is there FB page http://
> www.facebook.com/PureWC
> Here is the record breaking 98 mph electric boat.
> http://www.youtube.com/watch?v=-yNu2_LlO9s
>
> Also there is an electric outboard made in the Miami area that can
> hit 40-45 knots.
> There are quite a few people out there doing this stuff, they are
> just not getting their marketing out there as good as the ICE guys.
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