Props for semi-surface piercing outboard application?

[kentuckydiesel]

I have been back and fourth about keeping my twin Johnson 70s on my '23 Lone Star CruiseLiner. The boat has a fairly light aluminum hull, and has a very shallow draft, but the engines don't have power trim/tilt, which keeps me out of the shallower areas where I would like to go. I had been considering converting the boat to inboard jet propulsion, but with the engines being in great operating condition, I hate to get rid of them and go through a bunch of extra effort converting my boat over to something it wasn't ever made to be.

Lately I have been considering fabricating a hydraulic set-back jack plate for the engines, which would allow me to have adjustability for trim, and raise/lower the engines as needed.

I am wondering, if I do this, would there be a good prop for the 70s which would allow me to raise them high enough to operate as a semi-surface piercing application like a bunch of guys do with speed applications? I would be doing this mainly to be able to run in shallower water, but wouldn't mind if there were some side benefits of less drag.

Thanks,

Phillip

 

[Texasmark]

Re: Props for semi-surface piercing outboard application?

Cupping helps to prevent "blow out". However, if you aren't going WOT in your shallow water, which I would think a bad idea for safety reasons, I doubt it would be that much of a problem. I think the jack plate is a great idea. I was going to suggest it. Turning Point Hustler is on sale on site and is a cupped alum prop for around a hundred bucks! Select props at the top of this page.

HTH,
Mark

 

[steelespike]

Re: Props for semi-surface piercing outboard application?

No doubt a twin setup is really cool but ::
assuming your 70s are from the 70s they weigh 220 lbs each A single 135 same age is 271 lbs.
Less draft,quicker hole shot more efficient setup,less drag,less complication.
Easier to setup a jack plate.
There are jet setups for most common motors but with about a 30% reduction in power.
No need for a jack plate.