Built myself a jack plate today

[Kartracer]

Hardest part was getting the hardware correct. Saw Lowes a couple of times tonight. I am pretty happy with how it turned out. I could have done a lot better with the correct tools (at work) but I try to stay away from that place as much as I can. Setback is 5" and I have it set 1/2" above where it was on the transom to start with (anit-cav plate about 1/2" above pad). I think it is time to lose that huge fin. Don't plan on going up much until I get a water pressure gauge. Is there a rule on how far up per how much set back to keep the same amount of the lower in the water? Also, anyone have any input, does it look okay?

Boat specs: 10' GW Invader, 35hp merc.

Total cost: ~$80

Roughed in







The way it is designed, I can add power trim to it very easy with a standard hydraulic cylinder and a couple more pieces of aluminum angle. I also have provisions for adjuster screws if I want to add them.

[Scream And Fly]

That's pretty cool. I like the boat too!

[Fish]

That's pretty cool. I like the boat too!

nice work, it looks good and GW's rock!

I believe the rule of thumb is 1" up for every 4" back, but I am not positive, hopefully someone else will chime in.

[Kartracer]

Thanks.

I forgot to give credit for the design. I found the plans here: http://www.dillon-racing.com/jackplate/index.htm

[fastlane35]

hey it look goo dand it works

[Instigator]

I too like the old Invaders.

I think your #'s are correct Fish.

Gary

[Kartracer]

It worked great on my first trip out. Nothing moved or slipped. I moved the engine up another inch before I went out to start with it about the same as before. I didn't see much difference in speed, but I did notice that it planed out a little better and was a bit smoother when I had more trim. I took the fin off and didn't exactly like the results. The boat wouldn't plane at the highest trim setting at all and at other trim settings it didn't get out of the water very quickly. I think it is going back on. Would I bet better off with an aluminum one for less drag?

I did get 2 more MPH out of it to put me up to 38 MPH top speed, but I think that was thanks to a 2 MPH current. I'll take what I can get though.

[Instigator]

small boats and motors. Spent 9 yrs crawling on the front deck of race boats to get them on plane and on buddies 12' speed boats similar to yours.

Due to the short length (epecially relative to width) it will always have a "rear" weight bias making it hard to plane.
W/a motor w/no trim you have to pick a "setting" aiding getting on "plane" or top end but you can't have both.
Also with the speeds your running, don't expect to see much with increased motor height until you start running some "perf" props and then it is as much prop as motor height.
The easy answer is "power trim". Huge improvement to a boat of that style.
Either add on or a newer motor with in built on.

I just biiught a 13' Whaler w/a 28 HP motor w/no trim. One tilt pin position makes a huge difference in what the boat does.
I am currently shopping for a 50HP 2 cyl OMC w/trim.
If you really like your boat and plan on keeping it you might keep your eye open for something with trim.
I would guess something similar on your boat would probably make it a 50 MPH rocket.

[Kartracer]

Instigator, thanks a bunch. I realize how much I could benefit from power trim. I have been looking into adapting a cylinder to my current outboard and have also been looking for 15" motors in the 50-65 hp range with trim and haven't found too many candidates.

I have been curious with a performance prop if I would see much of a difference at that speed and with that little power. How much more would you think was possible with this setup?

[Instigator]

Instigator, thanks a bunch. I realize how much I could benefit from power trim. I have been looking into adapting a cylinder to my current outboard and have also been looking for 15" motors in the 50-65 hp range with trim and haven't found too many candidates.
I have been curious with a performance prop if I would see much of a difference at that speed and with that little power. How much more would you think was possible with this setup?

you could probably get 3 - 5 more w/a good prop which would also let you raise your motor 2 or 3 more inches but you will then have to be sure you are still getting cooling water to it.

I know that hull well and had buddies with them when I was a kid. You could build your own trim but you'll still be limited with the power you have.
A 15" would work if you could find one.

IMO, probably the best option for those boats is a later model 2 cyl OMC 50 w/trim (like I'm looking for for my Whaler). They are very, very strong motors (the 45SS race motors use this powerhead), near bullet proof, light for their power and fast.
Set up right you'd probably be in the mid 50's.

If that speed in a 10' boat doesn't scare you enough then the next choice would be the 3 cyl version of this same motor. (also raced and very fast)
They built them up to 70/75 Hp's.
I think my buddies with them were into the high 60's with this set up.

Both of the above motors also opens you up to a huge choice of props too compared to your current motor.

Gary

[whipper]

Looks great! Very resourceful.

[benski]

60 mph or even 50mph in that Invader will take bigger spheres than I've got. But the fabrication looks good and obviously is a benefit. Keep up the good work!