Engine height for V bottom

[A Mosny]

Many years ago I set up a small tunnel hull with a 75 hp Johnson and the rule of thumb was to raise the prop shaft 1" above the bottom of the boat. This worked well and I won a few races. I'm now building a small V bottom to sport around in the river. Since no experience with V bottom set up, my question is how high or low should the prop shaft be in relation to the bottom of the boat for a V bottom set up? This boat is a shallower V design and the same 75 Johnson will be the power but included will be a 6" set back due to a trim/tilt bracket being installed. My goal is to be quick down the river but still maintain some turn without blowing out the prop. Comments on prop pitch selection are also welcome. Any feedback is appreciated.

Thanks Anthony

[Ron Hill]

In the old days, we didn't have bottom water pick up nose cones, we didn't have transom jacks, we didn't have power trim and we had three blade propellers. Now there are more prop combinations than I can keep up with, three, four and five blades. I guess if there IS a "Rule of THUMB", it would be try something (Document it), try something else. The, try something else! Ask questions on BRF!

I know many a Vee Bottom running the prop shaft 2" above the bottom on a three cylinder motor.

ADD: Tunnel run the prop shaft 3 inches up into the tunnels on some boats!

[Chairman]

My experience with small (35hp GT Pro) v-bottoms is jack it up as high as you can without losing water pressure. For a 31.8 OMC without low water pickup, that ends up with the prop shaft about 1.5" below the pad.

[A Mosny]

The "try something then try something else" is the same way we did it back in the 70's. On occasion was expensive when the idea crashed and burned and my buddies ragged me for weeks. From 1.5" below to 2" above gives a range to select a start then adjust from there. I know what you mean with regard to props....pitch, diameter, number of blades, exhaust hub or no hub. I'll be thinking and asking more questions to BRF about this topic. Thanks for the tips. Much appreciated.

[89HST]

What boat?

[A Mosny]

15' Panther. Narrow boat with shallow V.

[Ron Hill]

Hey Chairman, what transom height do you run on a GT PROP Vee Bottom with stock water ick ups?

[Chairman]

I've made mine 20" high. If you mount the motor directly on the motorboard, that turns out to be a reasonable height. If you add a jackplate with a few inches of setback, there's room to go up another inch or two.

[omcstratos]

15' Panther. Narrow boat with shallow V.

I'm in the middle of a 13' panther right now. Do you have any pics of yours setup?

[A Mosny]

Chairman this seems to be the set up to start with. Transom has already been raised to support a long shaft which will put the shaft even with the bottom according to my tape measure. I'm sure there will be trials and adjustments to find a happy medium for getting out of the hole and turns without catching to much air or running hot. Comments are much appreciated.....Thanks

[A Mosny]

I'll post some when I get the boat in better shape. The floor was removed for a new fuel tank instillation, weight distribution an to remove some excess weight and inspect the strength so I would half to hang my head in shame to post now. The bottom needs to be straightened up also. It will be a several month project to complete and summer is coming so I'll get the fever and pontoon the lake.

[A Mosny]

Gentlemen, on another thought, have you any experience with hydraulic steering systems and speed boats?

[nhpoplin]

I'm in the middle of a 13' panther right now. Do you have any pics of yours setup?

You trying to bring that thing to the river omcstratos?!?!? Finally got my yamaha running and boys are starting to roll out what they been working on all winter. All i can say is its gonna be a FUN summer with some good races!!! you should come down sometime

[Fastjeff57]

Not here in eastern, PA. MORE snow coming next week!

When will this winter end?

Jeff

[nhpoplin]

When will this winter end

Man I'm drinking cold beer on the porch in 70 degree weather and ill be on the sandbar this weekend I don't know how you boys can stand it that far north

[A Mosny]

Sumter.....you hang out around the I-95 area of the lake. There is a cove on the south side that seems to be a "party" area during the summer. Careful after dark though...stumps-o-plenty.

[nhpoplin]

Actually I hang out on the river up around packs but just so happens I just moved to Bonneau which appears to right up the street from you A Mosny...been doing a little testing in the tail race lately

[A Mosny]

I'll see you this summer and most likely will be in the tailrace on Sunday. Many friends in Bonneau and Overton. I'm sure you know of the Red Neck Yot Club over by Coon Island.

[A Mosny]

Are you the same prop19 on e-bay where I'm shopping for a prop?

[nhpoplin]

I'll see you this summer and most likely will be in the tailrace on Sunday. Many friends in Bonneau and Overton. I'm sure you know of the Red Neck Yot Club over by Coon Island.

New to the area...trying to find the racing crowd around here...twisted my crank last weekend prolly be next weekend before I got it running again...what you running...most these fellas are running big boy toys...I gotta start another project to run with them...2.5 and a hydrosteam are in the plans

[Ron Hill]

Are you the same prop19 on e-bay where I'm shopping for a prop?

I started on E-bay ten years ago. Then, there were less than 1,000 propellers on E-Bay, today there are more than ten thousand props. I have more than 600 propellers listed myself. E-Bay has been a wonderful place for Hill Marine and Signature Propeller's to sell their products.

HillMarine.Com is our web page!

[nhpoplin]

I started on E-bay ten years ago. Then, there were less than 1,000 propellers on E-Bay, today there are more than ten thousand props. I have more than 600 propellers listed myself. E-Bay has been a wonderful place for Hill Marine and Signature Propeller's to sell their products.

HillMarine.Com is our web page!

Ron I owe you a few propellers...sorry for not being on the bone...took awhile to get my new motor going

[A Mosny]

Well....speed cost money....how fast you wanta go, is the phrase I always have heard. The larger boats are OK for the middle of the lake but the river gets busy on the weekends and I know of two boats at the bottom and 1 funeral so be careful and use safety gear. Rescue is not always close as on the race course and to much booze for some. Most I've watched are what I call modified tunnel hulls and there are a few Allison V bottoms. I'm restoring a '78 Johnson 75 hp stinger for this project. Bout finished with the motor and now the weather is warmer, glass resin will cure quicker so the boat is in progress. Grinding the glass is the worst part since it makes one itch like an old flea bag dog but it's gota be done. I'll finish with a custom wrap, hydraulic steering (got to think about this), trim/tilt system, and a few ideas to make it look sporty. Duck Dyanesty may want to buy it when I'm finished with all the "nice to haves, but not necessary" items such as instruments, LED lighting, built in fuel tank, and I'm working on a design for a swing away steering wheel (got to think about this also).

[A Mosny]

Business is good!! I'll be getting back to you on one or two and be asking some questions so hope you will pass on some of your knowledge. Do you know of any computer programs to input equipment data an it would recommend a prop? This may be a rainy day idea to work on. Like your picture. I'm an OMC fan and your in front of the Merc's. That will probably get me some feedback from the Merc fans, but that's all right, Merc has some good equipment also.

[omcstratos]

You trying to bring that thing to the river omcstratos?!?!? Finally got my yamaha running and boys are starting to roll out what they been working on all winter. All i can say is its gonna be a FUN summer with some good races!!! you should come down sometime

Well it's not mine, haha. I'm just helping out a friend getting his in shape. As well as a 13' Allison for another. I'm tight on money right now and don't have anything fast to run.