Jackplate History and Development

[NoLimits]

So I understand the runabout/hydro guys in the 50s would use "speed sticks" under the transom clamps to raise the outboard up a bit, but when did the first adjustable jackplates come out on the market? When did the first power lift jackplates come out on the market? Just curious how we wound up where we are today.

[doug7488]

The first I ever saw one was in 1976/77 (?)
I was only 15/16 then
But an older friend was a machinist at Grumman
He made it there
It was hydraulic
I imagine it was copied off something existing
Had it in a 20’ Vulture with a 235 Evinrude
Boat ran real nice for back then
Teddy at Muscle Boats told him he’d never break the ‘Stream
and if he did he’d replace it
We’ll, he broke it
Ted tried to welch on the guarantee until he was threatened with bodily harm
My buddy did get a new boat
Good Times!

[powerabout]

OMC pioneered it in the late 60's with hydraulic swivel tubes on race engines, poor mans version is the jack plate.

[KIRCHNER]

YES the good ole days, early sixties, we all had a 1x2 furring strip under the clamp. standard equipment,wow..

[Tom Smyth]

here is a pic showing a manual jack plate made from 1/4 aluminum angle. I restored this boat, and it still had the original jack plate pieces with it. This boat was the Illinois state FJ champ in 1972. I copied the original pieces and made a new powder coated jack plate to its exact original design. Allows up / down adjustment in 1-inch increments.

[99fxst99]

Not sure if it's clear in these pictures, but we built stationary plates out of 1/4" 6061T6 which straddled the transom, with gussets welded at the ends. Used clamp screws with threaded aluminum bungs pressing on top of the transom to adjust the height. Roddie Walsh and I built a bunch of these for race, river, and bass boats before the hydraulic plates came out.

[skipe]

YES the good ole days, early sixties, we all had a 1x2 furring strip under the clamp. standard equipment,wow..

I did that on my Beismeyer with a 150 Merc back in '75. I could get it up to 75MPH.

[Pulsare2400]

The first I ever saw one was in 1976/77 (?)
I was only 15/16 then
But an older friend was a machinist at Grumman
He made it there
It was hydraulic
I imagine it was copied off something existing
Had it in a 20’ Vulture with a 235 Evinrude
Boat ran real nice for back then
Teddy at Muscle Boats told him he’d never break the ‘Stream
and if he did he’d replace it
We’ll, he broke it
Ted tried to welch on the guarantee until he was threatened with bodily harm
My buddy did get a new boat
Good Times!

Around 1979 I made a hydraulic jack plate for my 16 ft Sidewinder / 140 TOP. I used T6061 aluminum 2 x 2's and machined a 5/8" groove in each one to accept a 5/8" plate that rode in the groove. Bolted the 2x2" pieces to the transom with the plate between them. I used an OMC Prestolite trim pump and fastened one end to plate and the other to a piece of angle iron bolted to the transom. You could jack that TOP while it was accelerating under WOT!! I could raise it almost 6.5" higher than the transom height and it eliminated all the chine walking. That boat ran around 66 mph with a 23P Chopper.

[J.P.]

99fxst99 is that a Hydrastream Vandel.

[JBS]

I became interested in performance boats in the late '70s. That's probably about when I saw the first Jack plate. A jack plate and a big prop would make a fishing motor go from mild to wild! I also learned the hard way how high to jack a motor before you run out of water.

[99fxst99]

99fxst99 is that a Hydrastream Vandel.

No sir, not a Vandal but a Ventura II. Attached is the paperwork from when I bought it. Ran it one year with a 1500 Jblock then when the 175 came out we upgraded to one of those.

[NoLimits]

How did sanctioned race events handle adjustable jackplates? I don't even mean hydraulic, like.... when people started showing up with the aluminum ones with multiple positions, was this allowed vs furring strips? And when hydraulic systems came to be, how did racing bodies react to it?

[takuma]

It's interesting to trace the evolution of the jackplate in outboard motor technology. While the "speed sticks" you mention were a makeshift solution for raising the outboard motor, adjustable jackplates became available on the market in the 1960s, allowing for greater fine-tuning of motor height and performance. Power lift jackplates, which are now commonplace, were developed in the 1980s, making it even easier to adjust motor height on the fly. The continued innovation and refinement of outboard motor technology over the decades have greatly improved the efficiency and performance of boats, leading to the advanced designs we have today. I used to writing residency personal statement for myself about that topic.

[J.P.]

99Fxst99 My cousin ran a 14 ft vandel center steer with a 140 OMC with a speedmaster and his buddy had the 16Ft Ventura II with a 235 OMC in the mid 80's.

Thanks for posting the details.