Prop shaft height with a bracket

[sixmassive]

I am trying to find the best propshaft hight in my boat and i also want to get a more modern bracket.

I was thinking i could buy a manual jackplate, then bring my GIL bracket to a welder so he can shorten it, so the total length of bracket w/ jackplate would be the desired final setback length, find the proper height, and then get a new bracket made and mount it to that height. that would save me from drilling tons of holes in my transom i guess.

Do they make jackplates for offshore use that you would trust?
Once the motor is mounted you can't really change the height without a jackplate correct?

thanks!

[HStream1]

With out knowing what type of boat/set up only a few questions can be answered. Pictures of your current set up would also help.

1st how much set back are you seeking? If it is a standard you can buy manual adjustable jack plates from 4 to 12" that will support 300+ HP and the holes should match the engine you currently have unless I'm missing something.

Here's the way I start.

(1) level the boat using the bottom/pad.

(2) remove the prop and using a torpedo level also level the engine at the prop shaft.

(3) Raise or lower the engine until the center line of the prop shaft is even with the bottom of the boat.

This is your starting point.

Do a couple WOT runs. record your speed and RPM's.

Raise or lower the engine in no more than 1/4" incriments repeating the WOT runs and recording the data.

When you find that sweet spot you'll know it!!!

And only make one change at a time. To many different changes and you don't know what did what.

Hope this helps.

[sixmassive]

26" sutphen Rum Runner
V8 johnson with 25" shaft. 32" setback due to the engine havin to tilt up.
The prop is about 2" above the bottom i think, havent measured it.

I would like to move the motor closer to the transom but i am not quite sure of the bet setup. This is the only 26 sutphen rigged with a Single O/B ever built. Most of the O/B models were twin merc 260s that had 23" setback. I can calculate the difference in weight moments but i dont know where the LCG is

http://i94.photobucket.com/albums/l96/isvbadman/photo-2.jpg

[rchevelle71]

26" sutphen Rum Runner
V8 johnson with 25" shaft. 32" setback due to the engine havin to tilt up.
The prop is about 2" above the bottom i think, havent measured it.

I would like to move the motor closer to the transom but i am not quite sure of the bet setup. This is the only 26 sutphen rigged with a Single O/B ever built. Most of the O/B models were twin merc 260s that had 23" setback. I can calculate the difference in weight moments but i dont know where the LCG is

http://i94.photobucket.com/albums/l96/isvbadman/photo-2.jpg

That is a heavy motor to have 32" back, from the looks of the pics, your prop is not 2" above the bottom, but could be the angle. I run my 24 pantera 24" back, and right now the shaft is similar to the way yours looks in the pic a few inches below the bottom, but mine also has a small pad. If you need a guy to make you a bracket, I have a welder in hialeah that did mine for a decent price.

[HStream1]

Well forget the set up I mentioned unless you are going to modify that lower to a LWPU. From the looks of that picture once you tilt the engine down you'll be below the botton by 2" +.

And :iagree: 32" is alot od set back for that engine/boat.

[sixmassive]

32 is the only way to tilt the motor all the way up, that is the reason it is that much. Richie Sutphen said that is too much setback, but He hasnt e mailed me back a figure that should be a little better.

I'll be putting probabaly a nose cone on it. dont know about the low water pickup. I'll be running rough seas and stuff.
JamesGang had a 31 with twin V8s and had them on 32" setback

[rchevelle71]

32 is the only way to tilt the motor all the way up, that is the reason it is that much. Richie Sutphen said that is too much setback, but He hasnt e mailed me back a figure that should be a little better.



That is why when I filled in my splashwell, I left the deck with the angle, stepdown. last pic is before tearing it down.

[sixmassive]

Thanks! I followed your build thread. I wouldn't mind hacking away at my transom for motor clearance, i am pretty experienced in fiberglass work. I would address that after i got the height determined. I also need to get a water pressure sensor to determine how high the motor is so it doesn't dehydrate. With a new bracket i want to beef up the Transom and run a brace across the upper mounts.

Maybe we'll meet up on the next run in a week or so. I can follow you to some spots.

[activator22]

What about going with a power jackplate, IIRC there are a couple out there for the V8's - if you had 5"+ inches of vertical trav, you would not need full tilt to get the bottom of the skeg higher then the bottom of the boat - maybe just 30-40 degrees. Plus the higher you go, the more clearance you are going to get on the cowl/rear deck

That should let you shorten up the setback a fair amount.

[sixmassive]

Would it be ideal for offshore though. I'll go out in almost anything

[activator22]

Shaun Torrente must be doing something similar - doesn't look like a lot of setback on his re-rigged spectre

http://i199.photobucket.com/albums/aa193/boat42/cropped212.jpg

[sixmassive]

man he has no tilt! haha

[sixmassive]

Can you change the height of a Johnson without re mounting the bracket? I know you can with mercs but i cant look at my motor right now

[Smoking Joe]

What about going with a power jackplate, IIRC there are a couple out there for the V8's - if you had 5"+ inches of vertical trav, you would not need full tilt to get the bottom of the skeg higher then the bottom of the boat - maybe just 30-40 degrees. Plus the higher you go, the more clearance you are going to get on the cowl/rear deck

That should let you shorten up the setback a fair amount.

Next year, I am looking to mount a V8 Johnson 300 with 20inch offshore leg on the back of the Wellcraft Nova. I was also looking to use a powered Jackplate to give me clearance for tilting the engine.

I was hoping not to have to scollop the rear transom area to allow clear tilting of the engine.